Search

Background: The WFS1 gene encodes the protein wolframin, which is crucial for maintaining endoplasmic reticulum homeostasis. Variants in this gene are predominantly associated with Wolfram syndrome and have been implicated in other disorders such as diabetes mellitus and psychiatric diseases, which increases the rate of clinical misdiagnosis. Methods: Patients were diagnosed with early-onset unclassified diabetes according to their clinical and laboratory data. We performed whole-exome sequencing (WES) in 165 patients, interpreting variants according to the American College of Medical Genetics/Association for Molecular Pathology (ACMG/AMP) 2015 guidelines. Variant verification was done by Sanger sequencing. In vitro experiments were conducted to evaluate the effects of WFS1 compound heterozygous variants. Results: We identified WFS1 compound heterozygous variants (p.A214fs*74/ p.F329I and p.I427S/p.I304T) in two patients with Wolfram Syndrome-Like disorders (WSLD). Both WFS1 compound heterozygous variants were associated with increased ER stress, reduced cell viability, and decreased SERCA2b mRNA levels. Additionally, pathogenic or likely pathogenic WFS1 heterozygous variants were identified in the other three patients. Conclusion: Our results underscore the importance of early genetic testing for diagnosing young-onset diabetes and highlight the clinical relevance of WFS1 variants in increasing ER stress and reducing cell viability. Incorporating these genetic insights into clinical practice can reduce misdiagnoses and improve treatment strategies for related disorders. [ABSTRACT FROM AUTHOR]

Background: Feeding difficulties frequently co‐occur with multisystem disorders attributed to rare genetic diseases. In this study, we aimed to describe the genetic manifestations and phenotype spectrum in infants experiencing feeding difficulties. Methods: This case series included infants under 6 months old with feeding difficulties admitted to the neonatal department of Children's Hospital, Zhejiang University School of Medicine from October 2018 to May 2022. All infants underwent whole‐exome sequencing (WES) during hospitalisation, and their clinical phenotypes and genetic results were analyzed. Results: Among 28 infants studied, nine were preterm and 19 were full‐term. Median admission age was 13.5 days (IQR 6.5, 35), with a median hospital stay of 16 days (IQR 10.5, 30). Overall, 12 (42.9%) cases were complicated with multiple malformations. Abnormal muscle tone (53.6%) and neurological issues (42.9%) were notable prevalent in these infants. Cranial MR abnormalities were noted in 96.2% of cases. Based on the combined analysis of WES results and clinical phenotypes, a total of 22 (78.3%) patients displayed disease‐related genetic variation identified through WES; among them, 15 (53.6%) patients received genetic diagnoses, while 7 (25%) patients were suspected diagnoses. Positive findings were more frequent in full‐term (89.5%) than preterm infants (55.6%). Ultimately, 24 (85.7%) patients were discharged alive, with 75% requiring post‐discharge tube feeding. Following discharge, five patients developed new symptoms linked to genetic variants, and two patients died. Conclusions: Feeding difficulty may constitute a facet of the phenotypic spectrum of rare genetic diseases. Whole‐exome sequencing can enhance molecular diagnosis accuracy for infants with feeding difficulties. [ABSTRACT FROM AUTHOR]

Introduction: Mutations in JAM2 have been linked to ~ 2% of primary familial brain calcification (PFBC) cases. PFBC is a rare neurological disorder characterized by excessive calcium deposition in the brain. It causes movement disorders and psychiatric problems. Six other genes were identified as causing PFBC. However, the genetic basis of ~ 50% of PFBC cases remains unknown. This study presented the results of a comprehensive analysis of five unrelated Iranian PFBC families. Methods: Clinical and paraclinical features of all patients were recorded. Whole-exome sequencing (WES) was done on the DNAs of probands. Data was analyzed, and haplotypes were determined. Results: WES identified two homozygous variants in JAM2 across four families: a novel variant, c.426dup:p.Ser143Leufs*23, in one family and a known mutation, c.685C > T:p.Arg229*, in the remaining three families. Haplotype analysis using six intragenic single-nucleotide polymorphisms (SNPs) in JAM2 revealed an identical haplotype in probands who carried the same mutation, whereas two other probands presented diverse haplotypes. Conclusion: Based on our results, p.Arg229* may be a founder mutation in the Iranian population. The variant has been detected in two out of seven other reported JAM2-related families who may originate from the Middle East and exhibit an identical haplotype. Even though this particular mutation may not be classified as a founder mutation, it does appear to be a hotspot, given that it has been observed in 45% of the 11 JAM2-associated families. Our study expanded the clinical features and mutation spectrum of JAM2 and revealed that mutations in JAM2 may be more common than previously reported. [ABSTRACT FROM AUTHOR]

Spinocerebellar ataxia type 11 (SCA11) is a rare disease and the tau tubulin kinase 2 (TTBK2) gene was the causative gene. To date, only six SCA11 families have been reported. Here, we reported a Chinese SCA11 pedigree with cerebellar ataxia. Both patients in the family demonstrated typical clinical features of cerebellar ataxia and cerebellar atrophy on brain MRI. A novel heterozygous duplication mutation (c.1211_1217dupAGGAGAA) of the TTBK2 gene was identified in the proband using whole-exome sequencing (WES), which resulted in a frameshift mutation and formed a premature stop codon (p. N406Kfs*47). The mutation was detected in the proband's affected brother, and his unaffected mother, who with a lower percentage of the mutation and considered as an asymptomatic mutation carrier. Our study delineated the genotypic spectrum of SCA11. [ABSTRACT FROM AUTHOR]

Background: The Triggering Receptor Expressed on Myeloid Cells 2 protein (TREM2) plays a crucial role in various biological processes, including osteoclast differentiation, and disease‐associated microglia (DAM) activation to regulate neuroinflammation, and phagocytosis in the brain. Genetic variations in TREM2 are implicated in neurodegenerative disorders, such as Nasu‐hakola disease (NHD), characterized by bone lesions, neuropsychiatric disorders, and early‐onset dementia. Methods: We studied 3 siblings with suspected NHD. Whole‐exome sequencing was conducted on the proband to identify the possible genetic cause(s) and by Sanger sequencing to validate the identified variants in the two other affected siblings, a healthy sister, and the parents. Results: We identified a novel homozygous deletion (c.549del; p.(Leu184Serfs*5)) in TREM2. Our literature review reveals 16 TREM2 mutations causing early‐onset dementia and bone lesions. Conclusion: These findings, alongside previous research, elucidate the clinical spectrum of TREM2‐related diseases, aiding accurate diagnosis and patient care. This knowledge is vital for understanding TREM2‐dependent DAM and its involvement in the pathogenesis of neurodevelopmental disorders which can help to develop targeted therapies and improve outcomes for TREM2‐affected individuals. [ABSTRACT FROM AUTHOR]

This study delves into the diagnostic yield of whole-exome sequencing (WES) in pediatric patients presenting with developmental delay/intellectual disability (DD/ID), while also exploring the utility of Reverse Phenotyping (RP) in refining diagnoses. A cohort of 100 pediatric patients underwent WES, yielding a diagnosis in 66% of cases. Notably, RP played a significant role in cases with negative prior genetic testing, underscoring its significance in complex diagnostic scenarios. The study revealed a spectrum of genetic conditions contributing to DD/ID, illustrating the heterogeneity of etiological factors. Despite challenges, WES demonstrated effectiveness, particularly in cases with metabolic abnormalities. Reverse phenotyping was indicated in half of the patients with positive WES findings. Neural network models exhibited moderate-to-exceptional predictive abilities for aiding in patient selection for WES and RP. These findings emphasize the importance of employing comprehensive genetic approaches and RP in unraveling the genetic underpinnings of DD/ID, thereby facilitating personalized management and genetic counseling for affected individuals and families. This research contributes insights into the genetic landscape of DD/ID, enhancing our understanding and guiding clinical practice in this particular field of clinical genetics. [ABSTRACT FROM AUTHOR]

Fibrillin-1 and fibrillin-2, encoded by FBN1 and FBN2, respectively, play significant roles in elastic fiber assembly, with pathogenic variants causing a diverse group of connective tissue disorders such as Marfan syndrome (MFS) and congenital contractural arachnodactyly (CCD). Different genomic variations may lead to heterogeneous phenotypic features and functional consequences. Recent high-throughput sequencing modalities have allowed detection of novel variants that may guide the care for patients and inform the genetic counseling for their families. We performed clinical phenotyping for two newborn infants with complex congenital heart defects. For genetic investigations, we employed next-generation sequencing strategies including whole-genome Single-Nucleotide Polymorphism (SNP) microarray for infant A with valvular insufficiency, aortic sinus dilatation, hydronephrosis, and dysmorphic features, and Trio whole-exome sequencing (WES) for infant B with dextro-transposition of the great arteries (D-TGA) and both parents. Infant A is a term male with neonatal marfanoid features, left-sided hydronephrosis, and complex congenital heart defects including tricuspid regurgitation, aortic sinus dilatation, patent foramen ovale, patent ductus arteriosus, mitral regurgitation, tricuspid regurgitation, aortic regurgitation, and pulmonary sinus dilatation. He developed severe persistent pulmonary hypertension and worsening acute hypercapnic hypoxemic respiratory failure, and subsequently expired on day of life (DOL) 10 after compassionate extubation. Cytogenomic whole-genome SNP microarray analysis revealed a deletion within the FBN1 gene spanning exons 7–30, which overlapped with the exon deletion hotspot region associated with neonatal Marfan syndrome. Infant B is a term male prenatally diagnosed with isolated D-TGA. He required balloon atrial septostomy on DOL 0 and subsequent atrial switch operation, atrial septal defect repair, and patent ductus arteriosus ligation on DOL 5. Trio-WES revealed compound heterozygous c.518C>T and c.8230T>G variants in the FBN2 gene. Zygosity analysis confirmed each of the variants was inherited from one of the parents who were healthy heterozygous carriers. Since his cardiac repair at birth, he has been growing and developing well without any further hospitalization. Our study highlights novel FBN1/FBN2 variants and signifies the phenotype–genotype association in two infants affected with complex congenital heart defects with and without dysmorphic features. These findings speak to the importance of next-generation high-throughput genomics for novel variant detection and the phenotypic variability associated with FBN1/FBN2 variants, particularly in the neonatal period, which may significantly impact clinical care and family counseling. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Feeding difficulties frequently co‐occur with multisystem disorders attributed to rare genetic diseases. In this study, we aimed to describe the genetic manifestations and phenotype spectrum in infants experiencing feeding difficulties. Methods This case series included infants under 6 months old with feeding difficulties admitted to the neonatal department of Children's Hospital, Zhejiang University School of Medicine from October 2018 to May 2022. All infants underwent whole‐exome sequencing (WES) during hospitalisation, and their clinical phenotypes and genetic results were analyzed. Results Among 28 infants studied, nine were preterm and 19 were full‐term. Median admission age was 13.5 days (IQR 6.5, 35), with a median hospital stay of 16 days (IQR 10.5, 30). Overall, 12 (42.9%) cases were complicated with multiple malformations. Abnormal muscle tone (53.6%) and neurological issues (42.9%) were notable prevalent in these infants. Cranial MR abnormalities were noted in 96.2% of cases. Based on the combined analysis of WES results and clinical phenotypes, a total of 22 (78.3%) patients displayed disease‐related genetic variation identified through WES; among them, 15 (53.6%) patients received genetic diagnoses, while 7 (25%) patients were suspected diagnoses. Positive findings were more frequent in full‐term (89.5%) than preterm infants (55.6%). Ultimately, 24 (85.7%) patients were discharged alive, with 75% requiring post‐discharge tube feeding. Following discharge, five patients developed new symptoms linked to genetic variants, and two patients died. Conclusions Feeding difficulty may constitute a facet of the phenotypic spectrum of rare genetic diseases. Whole‐exome sequencing can enhance molecular diagnosis accuracy for infants with feeding difficulties.

Abstract Background The methylcobalamin deficiency G (cblG) disorder, a rare autosomal recessive disease, is attributed to mutations in the MTR gene, resulting in heightened homocysteine levels and reduced methionine and megaloblastic anemia levels. This disease is predominantly diagnosed using MTR gene variation analysis. Case presentation Herein, we report the case of a 2.1-month-old Chinese girl with the cblG disorder with poor feeding, failure to thrive, and pancytopenia, esotropia, ocular nystagmus, and hypotonia. However, in order to determine the possible genetic cause of the disease, whole-exome sequencing was adopted and detected compound-heterozygous mutations in MTR gene. One was splicing site mutation c.1812 + 3A > G and the other was missense mutation c.2405G > A (p.A802G), which were likely disease-causing mutations (DM). Variant c.1812 + 3A > G has not been reported before in the literature. Conclusion Our data elucidated the genetic etiology of the patient and enriched the known spectrum of mutations in the MTR gene worldwide, offering exhaustive and invaluable insights for early diagnosis and appropriate medication of the cblG disorder.

Abstract Radioulnar synostosis with amegakaryocytic thrombocytopenia (RUSAT) type 2, caused by MDS1 and EVI1 complex locus (MECOM) gene mutations, is a rare inherited bone marrow failure syndrome (IBMFS) with skeletal anomalies, characterized by varying presentation of congenital thrombocytopenia (progressing to pancytopenia), bilateral proximal radioulnar synostosis, and other skeletal abnormalities. Due to limited knowledge and heterogenous manifestations, clinical diagnosis of the disease is challenging. Here we reported a novel MECOM mutation in a Chinese boy with typical clinical features for RUSAT-2. Trio-based whole exome sequencing of buccal swab revealed a novel heterozygous missense mutation in exon 11 of the MECOM gene (chr3:168818673; NM_001105078.3:c.2285G > A). The results strongly suggest that the variant was a germline mutation and disease-causing mutation. The patient received matched unrelated donor hematopoetic stem cell transplantation (HSCT). This finding was not only expanded the pathogenic mutation spectrum of MECOM gene, but also provided key information for clinical diagnosis and treatment of RUSAT-2.

Radioulnar synostosis with amegakaryocytic thrombocytopenia (RUSAT) type 2, caused by MDS1 and EVI1 complex locus (MECOM) gene mutations, is a rare inherited bone marrow failure syndrome (IBMFS) with skeletal anomalies, characterized by varying presentation of congenital thrombocytopenia (progressing to pancytopenia), bilateral proximal radioulnar synostosis, and other skeletal abnormalities. Due to limited knowledge and heterogenous manifestations, clinical diagnosis of the disease is challenging. Here we reported a novel MECOM mutation in a Chinese boy with typical clinical features for RUSAT-2. Trio-based whole exome sequencing of buccal swab revealed a novel heterozygous missense mutation in exon 11 of the MECOM gene (chr3:168818673; NM_001105078.3:c.2285G > A). The results strongly suggest that the variant was a germline mutation and disease-causing mutation. The patient received matched unrelated donor hematopoetic stem cell transplantation (HSCT). This finding was not only expanded the pathogenic mutation spectrum of MECOM gene, but also provided key information for clinical diagnosis and treatment of RUSAT-2. [ABSTRACT FROM AUTHOR]

Chorea-acanthocytosis (ChAc) is a rare autosomal recessive neurodegenerative disorder characterized by a variety of involuntary movements, predominantly chorea, and the presence of acanthocytosis in peripheral blood smears. ChAc is caused by mutations in the vacuolar protein sorting-associated protein 13A (VPS13A) gene. The aim of the present study was to conduct a clinical and genetic analysis of five patients with suspected ChAc in Iran. This study included five patients who were referred to the genetic department of the Endocrinology and Metabolism Research Institute between 2020 and 2022, with a suspicion of ChAc. Clinical features and the presence of characteristic MRI findings were evaluated in the patients. Whole-exome sequencing (WES) followed by Sanger sequencing was employed to identify the disease-causing variants. The functional effects of novel mutations were analyzed by specific bioinformatics prediction tools. WES and data analysis revealed the presence of five distinct VPS13A mutations in the patients, four of which were novel. These included one nonsense mutation (p.L984X), and three splice site mutations (c.755-1G>A, c.144+1 G>C, c.2512+1G>A). All mutations were validated by Sanger sequencing, and in silico analysis predicted that all mutations were pathogenic. This study provides the first molecular genetic characteristics of Iranian patients with ChAc, identifying four novel mutations in the VPS13A gene. These findings expand the VPS13A variants spectrum and confirm the clinical variability in ChAc patients. [ABSTRACT FROM AUTHOR]

Background: The methylcobalamin deficiency G (cblG) disorder, a rare autosomal recessive disease, is attributed to mutations in the MTR gene, resulting in heightened homocysteine levels and reduced methionine and megaloblastic anemia levels. This disease is predominantly diagnosed using MTR gene variation analysis. Case presentation: Herein, we report the case of a 2.1-month-old Chinese girl with the cblG disorder with poor feeding, failure to thrive, and pancytopenia, esotropia, ocular nystagmus, and hypotonia. However, in order to determine the possible genetic cause of the disease, whole-exome sequencing was adopted and detected compound-heterozygous mutations in MTR gene. One was splicing site mutation c.1812 + 3A > G and the other was missense mutation c.2405G > A (p.A802G), which were likely disease-causing mutations (DM). Variant c.1812 + 3A > G has not been reported before in the literature. Conclusion: Our data elucidated the genetic etiology of the patient and enriched the known spectrum of mutations in the MTR gene worldwide, offering exhaustive and invaluable insights for early diagnosis and appropriate medication of the cblG disorder. [ABSTRACT FROM AUTHOR]

Nonsyndromic hearing loss (NSHL) is a genetically diverse, highly heterogeneous condition characterised by deafness, and Gasdermin E (GSDME) variants have been identified as directly inducing autosomal dominant NSHL. While many NSHL cases associated with GSDME involve the skipping of exon 8, there is another, less understood pathogenic insertion variant specifically found in Chinese pedigrees that causes deafness, known as autosomal dominant 5 (DFNA5) hearing loss. In this study, we recruited a large Chinese pedigree, conducted whole‐exome and Sanger sequencing to serve as a comprehensive clinical examination, and extracted genomic DNA samples for co‐segregation analysis of the members. Conservation and expression analyses for GSDME were also conducted. Our clinical examinations revealed an autosomal dominant phenotype of hearing loss in the family. Genetic analysis identified a novel insertion variant in GSDME exon 8 (GSDME: NM_004403.3: c.1113_1114insGGGGTGCAGCTTACAGGGTGGGTGT: p. P372fs*36). This variant is segregated with the deafness phenotype of this pedigree. The GSDME gene was highly conserved in the different species we analysed, and its mRNA expression was ubiquitously low in different human tissues. In conclusion, we have successfully identified a novel pathogenic insertion variant of GSDME in a Chinese pedigree that causes deafness, shedding light on the genetic basis of hearing loss within this specific family. Our findings expand the spectrum of known variants associated with GSDME‐related deafness and may further support both the underlying gain‐of‐function mechanism and functional associations of GSDME hearing loss variants. [ABSTRACT FROM AUTHOR]

Abstract Background The Triggering Receptor Expressed on Myeloid Cells 2 protein (TREM2) plays a crucial role in various biological processes, including osteoclast differentiation, and disease‐associated microglia (DAM) activation to regulate neuroinflammation, and phagocytosis in the brain. Genetic variations in TREM2 are implicated in neurodegenerative disorders, such as Nasu‐hakola disease (NHD), characterized by bone lesions, neuropsychiatric disorders, and early‐onset dementia. Methods We studied 3 siblings with suspected NHD. Whole‐exome sequencing was conducted on the proband to identify the possible genetic cause(s) and by Sanger sequencing to validate the identified variants in the two other affected siblings, a healthy sister, and the parents. Results We identified a novel homozygous deletion (c.549del; p.(Leu184Serfs*5)) in TREM2. Our literature review reveals 16 TREM2 mutations causing early‐onset dementia and bone lesions. Conclusion These findings, alongside previous research, elucidate the clinical spectrum of TREM2‐related diseases, aiding accurate diagnosis and patient care. This knowledge is vital for understanding TREM2‐dependent DAM and its involvement in the pathogenesis of neurodevelopmental disorders which can help to develop targeted therapies and improve outcomes for TREM2‐affected individuals.

Abstract Background Premature ovarian insufficiency (POI) is a highly heterogeneous disease, and up to 25% of the cases can be explained by genetic causes. G protein-coupled receptor 3 (GPR3) plays an important role in oocyte arrest, and Gpr3-deficient mice exhibited POI-like phenotypes. Case presentation We identified two heterozygous missense variants of GPR3: NM_005281: c.C973T (p.R325C) and c.G772A (p.A258T) in two sporadic Han Chinese POI cases through whole exome sequencing and genetic analysis. The two patients were diagnosed as POI in their late 20s, presenting elevated serum levels of follicle stimulating hormone and secondary amenorrhea. Both variants are very rare in the population databases of ExAC, gnomAD and PGG.Han. The affected amino acids are conserved across species and the mutated amino acids are predicted deleterious with bioinformatics prediction tools and the protein three-dimensional structure analysis. Conclusions It is the first report of rare GPR3 variants associated with POI women, providing an important piece of evidence for GPR3 as a candidate gene which should be screened in POI. This finding suggested the necessity of including GPR3 in etiology study and genetic counseling of POI patients.

Kawasaki disease (KD) is an autoimmune disease of unknown etiology and has become a main cause of childhood acquired heart disease. KD is more prevalent in males than in females. The reason for this sex bias is unknown. Here, we used whole-exome sequencing (WES) to identify significantly different variants between male and female KD patients. From WES result, a total of 19,500 shared genetic variants in 8421 genes were captured via a series of filters. Further comparisons based on sex were performed to obtain 34 potential sex-biased variants in 34 genes for GO and Reactome Gene Sets enrichment analyses. Moreover, we selected 6 variants associated with immune, cells adhesion, platelet function, homeostasis, and ion channel signaling and expanded the sample size (1247 KD patients containing 713 males and 534 females, 803 healthy population containing 481 males and 322 females) for genotyping validation. From the results, USH2A/rs148135241, LMO7/rs142687160, CEMIP/rs12441101, and EFCC1/rs142391828 presented significant differences of alleles/genotypes frequency distributions between male and female only in KD patients (which were consistent with the result of WES analysis) but not in healthy population. In addition, the result also found that only EFCC1/rs142391828 polymorphism was associated with KD susceptibility. This result suggested that those four variants might play critical roles in sex bias in KD. The study would be in favor of a sex-specific genome atlas establishing and novel sex-specific precision therapies development for KD. [ABSTRACT FROM AUTHOR]

Background: Premature ovarian insufficiency (POI) is a highly heterogeneous disease, and up to 25% of the cases can be explained by genetic causes. G protein-coupled receptor 3 (GPR3) plays an important role in oocyte arrest, and Gpr3-deficient mice exhibited POI-like phenotypes. Case presentation: We identified two heterozygous missense variants of GPR3: NM_005281: c.C973T (p.R325C) and c.G772A (p.A258T) in two sporadic Han Chinese POI cases through whole exome sequencing and genetic analysis. The two patients were diagnosed as POI in their late 20s, presenting elevated serum levels of follicle stimulating hormone and secondary amenorrhea. Both variants are very rare in the population databases of ExAC, gnomAD and PGG.Han. The affected amino acids are conserved across species and the mutated amino acids are predicted deleterious with bioinformatics prediction tools and the protein three-dimensional structure analysis. Conclusions: It is the first report of rare GPR3 variants associated with POI women, providing an important piece of evidence for GPR3 as a candidate gene which should be screened in POI. This finding suggested the necessity of including GPR3 in etiology study and genetic counseling of POI patients. [ABSTRACT FROM AUTHOR]

Background and aims: The occurrence of thiamine metabolism dysfunction syndrome (THMD), a rare autosomal recessive condition, may be linked to various mutations found in the TPK1 and SLC19A3 genes. The disease chiefly manifests through ataxia, muscle hypotonia, abrupt or subacute onset encephalopathy, and a decline in developmental milestones achieved during the early stages of infancy. We present findings from an investigation that involved two individuals from Iran, both of whom experienced seizures along with ataxia and hypotonia. The underlying genetic causes were found with the use of next-generation sequencing (NGS) technology, which has facilitated the detection of causal changes in a variety of genetic disorders. Material and methods: The selection of cases for this study was based on the phenotypic and genetic information that was obtainable from the Center for Comprehensive Genetic Services. The genetic basis for the problems observed among the participants was determined through the application of whole-exome sequencing (WES). Subsequently, sanger sequencing was employed as a means of validating any identified variations suspected to be causative. Results: The first patient exhibited a homozygous mutation in the TPK1 gene, NM_022445.4:c.224 T > A:p.I75 N, resulting in the substitution of isoleucine for asparagine at position 75 (p.I75 N). In our investigation, patient 2 exhibited a homozygous variant, NM_025243.4:c.1385dupA:pY462X, within the SLC19A3 gene. Conclusions: Collectively, when presented with patients showcasing ataxia, encephalopathy, and basal ganglia necrosis, it is essential to account for thiamine deficiency in light of the potential advantages of prompt intervention. At times, it may be feasible to rectify this deficiency through the timely administration of thiamine dosages. Accordingly, based on the results of the current investigation, these variations may be useful for the diagnosis and management of patients with THMD.

Whole-exome sequencing is an evolving technology in perinatal diagnosis which allows identification of genetic etiologies that would otherwise go undetermined. In this case report, a 38-year-old Hispanic woman, G5P3013, with a monochorionic diamniotic twin gestation with one fetus displaying significant cranial abnormalities on prenatal ultrasound and magnetic resonance imaging (MRI) of the brain is presented. Fetal anomalies included bilateral ventriculomegaly, absent cavum septum pellucidum, and absent corpus callosum. Diagnostic amniocentesis with chromosome analysis, chromosomal microarray, alpha-fetoprotein, cytomegalovirus, toxoplasmosis, and parvovirus had normal results. Whole-exome sequencing for the anomalous fetus detected a de novo mosaic variant of uncertain significance (VUS) in the calcium/calmodulin dependent serine protein kinase (CASK) gene: c.1963 A > G (p.Asn655Asp). This variant was absent in the normal twin fetus, the mother, and the father. Pathogenic CASK gene mutations are associated with three syndromes: FG syndrome 4, intellectual developmental disorder and microcephaly with pontine and cerebellar hypoplasia (MICPCH), and intellectual developmental disorder with or without nystagmus. Whole-exome sequencing identified a potential etiology for the anomalies detected. The variant likely arose de novo and was the potential cause of the identified cranial abnormalities in one fetus of this monochorionic diamniotic twin gestation. Whole-exome sequencing may provide additional diagnostic utility when standard diagnostic testing is noncontributory.

The aim of this study was to screen potential susceptibility genes using whole-exome sequencing (WES) in 15 Han Chinese patients with stage III or IV periodontitis and to evaluate the quantity and quality of genomic DNA extracted from saliva. DNA was extracted from saliva epithelial cells, quality-tested, and then subjected to WES and bioinformatics analyses. All variation loci were analyzed and interpreted following the American College of Medical Genetics and Genomics (ACMG) criteria. Candidate pathogenic variation loci were identified and verified using Sanger sequencing. Correlation and functional analyses of the candidate genes were used to identify potential susceptibility genes in patients with severe periodontitis. LFNG, LENG8, NPHS1, HFE, ILDR1, and DMXL2 genes were identified in over two cases each with shared mutations. Following these analyses, the DMXL2 gene was identified as being associated with stage III and IV periodontitis. These results suggest a potential pathophysiological risk mechanism for periodontitis, but need to be verified through larger clinical studies and mechanistic experiments to determine the pathogenicity of these gene mutations and their generalizability to a wider population of periodontitis patients. By screening candidate pathogenic variation loci using WES in 15 Han Chinese patients with stage III or IV periodontitis, our study could provide a pipeline and feasibility support for the identification of susceptibility genes in patients with stage III and IV periodontitis.

Objective·To screen mutations of key genes in the leptin-melanocyte stimulating hormone (LEP-MSH) pathway by whole-exome sequencing (WES) in the obese cohort.Methods·A total of 119 obese patients aged 17－65 years old with body mass index (BMI)≥34 kg/m2, who underwent laparoscopic sleeve gastrectomy from January 2011 to July 2019 at Shanghai Sixth People′s Hospital, Shanghai Jiao Tong University School of Medicine were collected. The peripheral blood samples of the research subjects were collected, and whole genome DNA was extracted to perform WES. Bioinformatic methods were applied to detect the mutations in 16 genes in the LEP-MSH pathway (ADCY3, AGRP, BDNF, KSR2, LEP, LEPR, MC3R, MC4R, MCHR1, MRAP2, NTRK2, PCSK1, PHIP, POMC, SH2B1, and SIM1). Rare variants with the minor allele frequency in the total population less than 0.02 and in the East Asian population less than 0.01 in the 1000 Genome (1000G), Exome Aggregation Consortium (ExAC) and Genome Aggregation Database (gnomAD) were selected for subsequent analysis. Six pieces of prediction software were used to evaluate the deleteriousness of the mutations. Finally, based on the clinical information of each patient, the pathogenicity of all variants was determined according to the guidelines of America College of Medical Genetics and Genomics (ACMG), and only the "pathogenic", "likely pathogenic", and "uncertain significance" variants were retained.Results·A total of 26 variants, 22 kinds of variants were detected in 24 patients from 119 subjects, all of which were heterozygous mutations. The detected variants included 7 in SH2B1 gene (accounting for 26.92% of the total variants), 4 in MCHR1 gene (accounting for 15.38%), 3 in PHIP gene (accounting for 11.53%), 2 in ADCY3 and LEPR genes (accounting for 7.69%, respectively), and 1 in LEP, NTRK2, AGRP, KSR2, MC3R, MC4R, BDNF, and PCSK1 genes, respectively (accounting for 3.85%, respectively). There were 3 patients having the same mutation site in SH2B1 gene, and 2 patients having the same mutation sites in LEPR gene and MCHR1 gene, respectively. In addition, among these mutations, there were 12 ones not included in the East Asian population in 3 public databases, which were novel mutations in the East Asian population, located in SH2B1 (p.V209I, p.R67C, and p.L149F), KSR2 (p.P155T), LEP (p.D106N), LEPR (p.W132R), PHIP (p.K1461R), BDNF (p.N84S), PCSK1 (p.R282W), NTRK2 (p.T732M), MC3R (p.S71P), and MC4R (p.W174X).Conclusion·A total of 22 kinds of rare variations possibly associated with obesity in the LEP-MSH pathway are detected, 12 of which are novel in the East Asian population.

This study delves into the diagnostic yield of whole-exome sequencing (WES) in pediatric patients presenting with developmental delay/intellectual disability (DD/ID), while also exploring the utility of Reverse Phenotyping (RP) in refining diagnoses. A cohort of 100 pediatric patients underwent WES, yielding a diagnosis in 66% of cases. Notably, RP played a significant role in cases with negative prior genetic testing, underscoring its significance in complex diagnostic scenarios. The study revealed a spectrum of genetic conditions contributing to DD/ID, illustrating the heterogeneity of etiological factors. Despite challenges, WES demonstrated effectiveness, particularly in cases with metabolic abnormalities. Reverse phenotyping was indicated in half of the patients with positive WES findings. Neural network models exhibited moderate-to-exceptional predictive abilities for aiding in patient selection for WES and RP. These findings emphasize the importance of employing comprehensive genetic approaches and RP in unraveling the genetic underpinnings of DD/ID, thereby facilitating personalized management and genetic counseling for affected individuals and families. This research contributes insights into the genetic landscape of DD/ID, enhancing our understanding and guiding clinical practice in this particular field of clinical genetics.

Fibrillin-1 and fibrillin-2, encoded by FBN1 and FBN2, respectively, play significant roles in elastic fiber assembly, with pathogenic variants causing a diverse group of connective tissue disorders such as Marfan syndrome (MFS) and congenital contractural arachnodactyly (CCD). Different genomic variations may lead to heterogeneous phenotypic features and functional consequences. Recent high-throughput sequencing modalities have allowed detection of novel variants that may guide the care for patients and inform the genetic counseling for their families. We performed clinical phenotyping for two newborn infants with complex congenital heart defects. For genetic investigations, we employed next-generation sequencing strategies including whole-genome Single-Nucleotide Polymorphism (SNP) microarray for infant A with valvular insufficiency, aortic sinus dilatation, hydronephrosis, and dysmorphic features, and Trio whole-exome sequencing (WES) for infant B with dextro-transposition of the great arteries (D-TGA) and both parents. Infant A is a term male with neonatal marfanoid features, left-sided hydronephrosis, and complex congenital heart defects including tricuspid regurgitation, aortic sinus dilatation, patent foramen ovale, patent ductus arteriosus, mitral regurgitation, tricuspid regurgitation, aortic regurgitation, and pulmonary sinus dilatation. He developed severe persistent pulmonary hypertension and worsening acute hypercapnic hypoxemic respiratory failure, and subsequently expired on day of life (DOL) 10 after compassionate extubation. Cytogenomic whole-genome SNP microarray analysis revealed a deletion within the FBN1 gene spanning exons 7–30, which overlapped with the exon deletion hotspot region associated with neonatal Marfan syndrome. Infant B is a term male prenatally diagnosed with isolated D-TGA. He required balloon atrial septostomy on DOL 0 and subsequent atrial switch operation, atrial septal defect repair, and patent ductus arteriosus ligation on DOL 5. Trio-WES revealed compound heterozygous c.518C>T and c.8230T>G variants in the FBN2 gene. Zygosity analysis confirmed each of the variants was inherited from one of the parents who were healthy heterozygous carriers. Since his cardiac repair at birth, he has been growing and developing well without any further hospitalization. Our study highlights novel FBN1/FBN2 variants and signifies the phenotype–genotype association in two infants affected with complex congenital heart defects with and without dysmorphic features. These findings speak to the importance of next-generation high-throughput genomics for novel variant detection and the phenotypic variability associated with FBN1/FBN2 variants, particularly in the neonatal period, which may significantly impact clinical care and family counseling.

Leber congenital amaurosis (LCA) is the most severe form of inherited retinal dystrophy. RPGRIP1-related LCA accounts for 5–6% of LCA. We performed whole-exome sequencing and whole-genome sequencing (WGS) on 29 patients with clinically suspected LCA and examined ophthalmic findings in patients with biallelic pathogenic variants of RPGRIP1. In addition to five previously reported cases, we identified five cases from four families with compound heterozygous RPGRIP1 variants using WGS. Five patients had null variants comprising frameshift variants, an Alu insertion, and microdeletions. A previously reported 1339 bp deletion involving exon 18 was found in four cases, and the deletion was relatively prevalent in the Japanese population (allele frequency: 0.002). Microdeletions involving exon 1 were detected in four cases. In patients with RPGRIP1 variants, visual acuity remained low, ranging from light perception to 0.2, and showed no correlation with age. In optical coherence tomography images, the ellipsoid zone (EZ) length decreased with age in all but one case of unimpaired EZ. The retinal structure was relatively preserved in all cases; however, there were cases with great differences in visual function compared to their siblings and a 56-year-old patient who still had a faint EZ line. Structural abnormalities may be important genetic causes of RPGRIP1-related retinal dystrophy in Japanese patients, and WGS was useful for detecting them. [ABSTRACT FROM AUTHOR]

A large body of evidence indicates that women with polycystic ovary syndrome (PCOS) have a higher risk of developing Hashimoto's thyroiditis (HT) than healthy individuals. Given the strong genetic impact on both diseases, common predisposing genetic factors are possibly involved but are not fully understood. Here, we performed whole-exome sequencing (WES) for 250 women with sporadic PCOS, HT, combined PCOS and HT (PCOS+HT), and healthy controls to explore the genetic background of the joint occurrence of PCOS and HT. Based on relevant comparative analyses, multivariate logistic regression prediction modeling, and the most informative feature selection using the Monte Carlo feature selection and interdependency discovery algorithm, 77 variants were selected for further validation by TaqMan genotyping in a group of 533 patients. In the allele frequency test, variants in RAB6A, GBP3, and FNDC7 genes were found to significantly (padjusted < 0.05) differentiated the PCOS+HT and PCOS groups, variant in HIF3A differentiated the PCOS+HT and HT groups, whereas variants in CDK20 and CCDC71 differentiated the PCOS+HT and both single disorder groups. TaqMan genotyping data were used to create final prediction models, which differentiated between PCOS+HT and PCOS or HT with a prediction accuracy of AUC = 0.78. Using a 70% cutoff of the prediction score improved the model parameters, increasing the AUC value to 0.87. In summary, we demonstrated the polygenic burden of both PCOS and HT, and many common and intersecting signaling pathways and biological processes whose disorders mutually predispose patients to the development of both diseases. [ABSTRACT FROM AUTHOR]

Chronic pain is a prevalent disease with increasing clinical challenges. Genome-wide association studies in chronic pain patients have identified hundreds of common pathogenic variants, yet they only explained a portion of individual variance of chronic pain. With the advances in next-generation sequencing technologies, it is now feasible to conduct rarer variants studies in large-scale databases. Here, we performed gene-based rare variant analyses in 200,000 human subjects in the UK biobank whole-exome sequencing database for investigating 9 different chronic pain states and validated our findings in 3 other large-scale databases. Our analyses identified the SLC13A1 gene coding for sodium/sulfate symporter associated with chronic back pain and multisite pain at the genome-wide level and with chronic headache, knee, and neck and shoulder pain at the nominal level. Seven loss-of-function rare variants were identified within the gene locus potentially contributing to the development of chronic pain, with 2 of them individually associated with back pain and multisite pain. These 2 rare variants were then tested for replication in 3 other biobanks, and the strongest evidence was found for rs28364172 as an individual contributor. Transcriptional analyses of Slc13a1 in rodents showed substantial regulation of its expression in the dorsal root ganglia and the sciatic nerve in neuropathic pain assays. Our results stress the importance of the SLC13A1 gene in sulfate homeostasis in the nervous system and its critical role in preventing pain states, thus suggesting new therapeutic approaches for treating chronic pain in a personalized manner, especially in people with mutations in the SLC13A1 gene. [ABSTRACT FROM AUTHOR]

Objective·To screen mutations of key genes in the leptin-melanocyte stimulating hormone (LEP-MSH) pathway by whole-exome sequencing (WES) in the obese cohort. Methods·A total of 119 obese patients aged 17－65 years old with body mass index (BMI)≥34 kg/m2, who underwent laparoscopic sleeve gastrectomy from January 2011 to July 2019 at Shanghai Sixth People′s Hospital, Shanghai Jiao Tong University School of Medicine were collected. The peripheral blood samples of the research subjects were collected, and whole genome DNA was extracted to perform WES. Bioinformatic methods were applied to detect the mutationsin 16 genes in the LEP-MSH pathway (ADCY3, AGRP, BDNF, KSR2, LEP, LEPR, MC3R, MC4R, MCHR1, MRAP2, NTRK2, PCSK1, PHIP, POMC, SH2B1, and SIM1). Rare variants with the minor allele frequency in the total population less than 0.02 and in the East Asian population less than 0.01 in the 1000 Genome (1000G), Exome Aggregation Consortium (ExAC) and Genome Aggregation Database (gnomAD) were selected for subsequent analysis. Six pieces of prediction software were used to evaluate the deleteriousness of the mutations. Finally, based on the clinical information of each patient, the pathogenicity of all variants was determined according to the guidelines of America College of Medical Genetics and Genomics (ACMG), and only the "pathogenic", "likely pathogenic", and "uncertain significance" variants were retained. Results·A total of 26 variants, 22 kinds of variants were detected in 24 patients from 119 subjects, all of which were heterozygous mutations. The detected variants included 7 in SH2B1 gene (accounting for 26.92% of the total variants), 4 in MCHR1 gene (accounting for 15.38%), 3 in PHIP gene (accounting for 11.53%), 2 in ADCY3 and LEPR genes (accounting for 7.69%, respectively), and 1 in LEP, NTRK2, AGRP, KSR2, MC3R, MC4R, BDNF, and PCSK1 genes, respectively (accounting for 3.85%, respectively). There were 3 patients having the same mutation site in SH2B1 gene, and 2 patients having the same mutation sites in LEPR gene and MCHR1 gene, respectively. In addition, among these mutations, there were 12 ones not included in the East Asian population in 3 public databases, which were novel mutations in the East Asian population, located in SH2B1 (p.V209I, p.R67C, and p.L149F), KSR2 (p.P155T), LEP (p.D106N), LEPR (p.W132R), PHIP (p.K1461R), BDNF (p.N84S), PCSK1 (p.R282W), NTRK2 (p.T732M), MC3R (p.S71P), and MC4R (p. W174X). Conclusion· A total of 22 kinds of rare variations possibly associated with obesity in the LEP-MSH pathway are detected, 12 of which are novel in the East Asian population. [ABSTRACT FROM AUTHOR]

Objective: To define somatic variants of parathyroid adenoma (PA) and to provide novel insights into the underlying molecular mechanism of sporadic PA. Methods: Basic clinical characteristics and biochemical indices of 73 patients with PA were collected. Whole-exome sequencing was performed on matched tumor-constitutional DNA pairs to detect somatic alterations. Functional annotation was carried out by ingenuity pathway analysis afterward. The protein expression of the variant gene was confirmed by immunohistochemistry, and the relationship between genotype and phenotype was analyzed. Results: Somatic variants were identified in 1549 genes, with an average of 69 variants per tumor (range, 13-2109; total, 9083). Several novel recurrent somatic variants were detected, such as KMT2D (15/73), MUC4 (14/73), POTEH (13/73), CD22 (12/73), HSPA2 (12/73), HCFC1 (11/73), MAGEA1 (11/73), and SLC4A3 (11/73), besides the previously reported PA-related genes, including MEN1 (11/73), CASR (6/73), MTOR (4/73), ASXL3 (3/73), FAT1 (3/73), ZFX (5/73), EZH1 (2/73), POT1 (2/73), and EZH2 (1/73). Among them, KMT2D might be the candidate driver gene of PA. Crucially, 5 patients carried somatic mutations in CDC73, showed an aggressive phenotype similar to that of parathyroid carcinoma (PC), and had a decreased expression of parafibromin. Pathway analysis of recurrent potential PA-associated driver variant genes revealed functional enrichments in the signaling pathway of Notch. Conclusion: Our study expanded the pathogenic variant spectrum of PA and indicated that KMT2D might be a novel candidate driver gene and be considered as a diagnostic biomarker for PA. Meanwhile, CDC73 mutations might be an early developmental event from PA to PC. The results provided insights into elucidating the pathogenesis of parathyroid tumorigenesis and a certain basis for clinical diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Hereditary spastic paraplegia (HSP) refers to a group of heterogeneous neurological disorders mainly characterized by corticospinal degeneration (pure forms), but sometimes associated with additional neurological and extrapyramidal features (complex HSP). The advent of next-generation sequencing (NGS) has led to huge improvements in knowledge of HSP genetics and made it possible to clarify the genetic etiology of hundreds of "cold cases," accelerating the process of reaching a molecular diagnosis. The different NGS-based strategies currently employed as first-tier approaches most commonly involve the use of targeted resequencing panels and exome sequencing, whereas genome sequencing remains a second-tier approach because of its high costs. The question of which approach is the best is still widely debated, and many factors affect the choice. Here, we aim to analyze the diagnostic power of different NGS techniques applied in HSP, by reviewing 38 selected studies in which different strategies were applied in different-sized cohorts of patients with genetically uncharacterized HSP. [ABSTRACT FROM AUTHOR]

A large body of evidence indicates that women with polycystic ovary syndrome (PCOS) have a higher risk of developing Hashimoto’s thyroiditis (HT) than healthy individuals. Given the strong genetic impact on both diseases, common predisposing genetic factors are possibly involved but are not fully understood. Here, we performed whole-exome sequencing (WES) for 250 women with sporadic PCOS, HT, combined PCOS and HT (PCOS+HT), and healthy controls to explore the genetic background of the joint occurrence of PCOS and HT. Based on relevant comparative analyses, multivariate logistic regression prediction modeling, and the most informative feature selection using the Monte Carlo feature selection and interdependency discovery algorithm, 77 variants were selected for further validation by TaqMan genotyping in a group of 533 patients. In the allele frequency test, variants in RAB6A, GBP3, and FNDC7 genes were found to significantly (padjusted < 0.05) differentiated the PCOS+HT and PCOS groups, variant in HIF3A differentiated the PCOS+HT and HT groups, whereas variants in CDK20 and CCDC71 differentiated the PCOS+HT and both single disorder groups. TaqMan genotyping data were used to create final prediction models, which differentiated between PCOS+HT and PCOS or HT with a prediction accuracy of AUC = 0.78. Using a 70% cutoff of the prediction score improved the model parameters, increasing the AUC value to 0.87. In summary, we demonstrated the polygenic burden of both PCOS and HT, and many common and intersecting signaling pathways and biological processes whose disorders mutually predispose patients to the development of both diseases.

POLR3B gene encodes the 2nd largest catalytic subunit and affects the function of RNA polymerase III enzymes in transcription. Bi‐allelic variants in POLR3B pathogenically cause hypomyelinating leukodystrophy‐8 (HLD8). Herein, we recruited a family with two patients, who presented clinically with cerebellar atrophy, intellectual disability, hypogonadotropic hypogonadism, and visual problems. We identified the two affected siblings carrying the compound heterozygous variations (c.165_167del; c.1615G>T) in POLR3B by trio‐whole‐exome sequencing (trio‐WES). The qPCR and western blot showed that both transcriptional and translational levels of the mutation (c.165_167del, p.I55_K56delinsM) were sharply attenuated. Following that, a thorough functional examination of a zebrafish line disrupted for human POLR3B validated the pathogenic effects of the two mutations. Our research broadens the spectrum of HLD8‐related pathogenic POLR3B mutations and provides new molecular and animal evidence. [ABSTRACT FROM AUTHOR]

• NMNAT1 , a key enzyme for NAD+ synthesis , roles in the maintenance of NAD homeostasis of neurons. • Mutations in NMNAT1 cause syndromic and non-syndromic Leber congenital amaurosis-type 9 (LCA9). • For the first time, a probable association between a NMNAT1 variant and HSP disease is detected. • It seems NMNAT1 mutations can present phenotypic heterogeneity. • Phenotypic heterogeneity has already been reported in HSP cases with mutations in other genes. In the NAD biosynthetic network, the nicotinamide mononucleotide adenylyltransferase (NMNAT) enzyme fuels NAD as a co-substrate for a group of enzymes. Mutations in the nuclear-specific isoform, NMNAT1 , have been extensively reported as the cause of Leber congenital amaurosis-type 9 (LCA9). However, there are no reports of NMNAT1 mutations causing neurological disorders by disrupting the maintenance of physiological NAD homeostasis in other types of neurons. In this study, for the first time, the potential association between a NMNAT1 variant and hereditary spastic paraplegia (HSP) is described. Whole-exome sequencing was performed for two affected siblings diagnosed with HSP. Runs of homozygosity (ROH) were detected. The shared variants of the siblings located in the homozygosity blocks were selected. The candidate variant was amplified and Sanger sequenced in the proband and other family members. Homozygous variant c.769G> A :p.(Glu257Lys) in NMNAT1 , the most common variant of NMNAT1 in LCA9 patients, located in the ROH of chromosome 1, was detected as a probable disease-causing variant. After detection of the variant in NMNAT1 , as a LCA9-causative gene, ophthalmological and neurological re-evaluations were performed. No ophthalmological abnormality was detected and the clinical manifestations of these patients were completely consistent with pure HSP. No NMNAT1 variant had ever been previously reported in HSP patients. However, NMNAT1 variants have been reported in a syndromic form of LCA which is associated with ataxia. In conclusion, our patients expand the clinical spectrum of NMNAT1 variants and represent the first evidence of the probable correlation between NMNAT1 variants and HSP. [ABSTRACT FROM AUTHOR]

Abstract Background Central nervous system candidiasis due to Candida albicans (CNSC) in children is easily misdiagnosed and is associated with poor outcomes and a high mortality rate. There is no big data research or systematic review of CNSC. Methods Patients diagnosed as CNSC with positive culture results of Candida albicans in Beijing Children’s Hospital affiliated to Capital Medical University from March 2010 to March 2019 were included. Patients receiving immunosuppressive therapy or transplantation, or with malignant tumours were excluded. We analysed the clinical characteristics, follow-up results, drug susceptibility tests and whole-exome sequencing (WES) results. Results Thirty-three definitive patients were enrolled, including 22 males and 11 females. Twenty-five patients suffered from CNSC when they were less than 1 year old, and a total of 29 patients had high-risk factors. The main clinical manifestations were fever, convulsions, and positive neurological signs. Twenty-two patients had CNS infections alone, and 11 patients had CNS infections combined with invasive infections involving multiple sites. Twenty-seven cases had a positive CSF and/or blood culture at our hospital. All strains were susceptible to fluconazole, and 2 strains had intermediate susceptibility to voriconazole. As for amphotericin B, all the strains were wild type (WT). WES of 16 patients revealed 2 cases with CARD9 mutations, who suffered from recurrent onychomycosis or thrush before. Conclusion CNSC mostly existed in children younger than 1 year old, who all had underlying risk factors. CNSC patients with onset at an older age or with recurrent superficial fungal infections might have primary immunodeficiency.

Abstract Background Giant congenital melanocytic nevus (GCMN) is the benign nevomelanocytic proliferation. Mutations in NRAS have been previously detected in GCMN, but mutations in BRAF are generally lacking in the Chinese population. Mutated genes in this disease can estimate the risk of malignant transformation in GCMN. Therefore, it is worth investigating the genetic information of GCMN. Methods Here, we presented two cases of GCMN of the upper extremities. The clinical and histological data were analyzed. The whole exome sequencing (WES) was performed to investigate the mutational profile of peripheral venous blood (PB), normal skin (NS), small melanocytic nevus (SMN), deep penetrating and non-penetrating GCMN (dPGCMN and nPGCMN). Results We showed a reduction in the circumference of involved upper extremities in both patients. The clinical and histopathological data indicated the reduction of adipose tissue associated with the invasion of GCMN. The WES data revealed that MUC16, MAP3K15 and ABCA1 were novel potential candidate genes for the disease as well as biomarkers for predicting malignant transformation. Conclusion The MUC16, MAP3K15 and ABCA1 may serve as novel biomarkers for predicting malignant transformation and targets for the diagnoses and therapy for the GCMN.

Background: Non-syndromic oligodontia is characterized by the absence of six or more permanent teeth, excluding third molars, and can have aesthetic, masticatory, and psychological consequences. Previous studies have shown that PAX9 is associated with autosomal dominant forms of oligodontia but the precise molecular mechanisms are still unknown. Methods: Whole-exome and Sanger sequencing were performed on a cohort of approximately 28 probands with NSO, for mutation analysis. Bioinformatic analysis was performed on the potential variants. Immunofluorescence assay, western blotting, and qPCR were used to explore the preliminary functional impact of the variant PAX9 proteins. We reviewed PAX9-related NSO articles in PubMed to analyze the genotype-phenotype correlations. Results: We identified three novel PAX9 variants in Chinese Han families: c.152G>T (p. Gly51Val), c.239delC (p.Thr82Profs*3), and c.409C>T (q.Gln137Ter). In addition, two previously reported missense variants were identified: c.140G>C (p.Arg47Pro) and c.146C>T (p.Ser49Leu) (reference sequence NM_006194.4). Structural modeling revealed that all missense variants were located in the highly conserved paired domain. The other variants led to premature termination of the protein, causing structural impairment of the PAX9 protein. Immunofluorescence assay showed abnormal subcellular localizations of the missense variants (R47P, S49L, and G51V). In human dental pulp stem cells, western blotting and qPCR showed decreased expression of PAX9 variants (c.140G>C, p.R47P, and c.152G>T, p.G51V) compared with the wild-type group at both the transcription and translation levels. A review of published papers identified 64 PAX9 variants related to NSO and found that the most dominant feature was the high incidence of missing upper second molars, first molars, second premolars, and lower second molars. Conclusion: Three novel PAX9 variants were identified in Chinese Han families with NSO. These results extend the variant spectrum of PAX9 and provide a foundation for genetic diagnosis and counseling. [ABSTRACT FROM AUTHOR]

Simple Summary: The genomic landscape of breast cancer (BC) is complex. Previous research studies have not extensively elucidated the correlation of genotypes and allele variations of the PI3K, AKT-1, KLF-14, MDM4 and miRNAs 27a, miR-196a genes with the predisposition of Breast cancer in Saudi Arabia. Therefore, to cover this area of research, we conducted a case-control study on 230 subjects (115 cases and 115 controls). Genotyping was studied by using the ARMS-PCR and results were confirmed by Sanger sequencing. The novel and known gene variants were studied by Whole-exome sequencing using Illumina NovaSeq 6000 platform. Strong association was reported between the PI3K-AKT signaling pathway genes and KLF 14-AA, MDM4-GA, miR27a-GG and miR-196a-CT gene variants with the breast cancer susceptibility and progression. The results could help to classify and identify those at risk for Breast cancer in the future. WES for provide insight toward disease mechanisms for the development of more effective therapies. Genome-wide association studies have reported link between SNPs and risk of breast cancer. This study investigated the association of the selected gene variants by predicting them as possible target genes. Molecular technique advances with the availability of whole-exome sequencing (WES), now offer opportunities for simultaneous investigations of many genes. The experimental protocol for PI3K, AKT-1, KLF-14, MDM4, miRNAs 27a, and miR-196a genotyping was done by ARMS-PCR and sanger sequencing. The novel and known gene variants were studied by Whole-exome sequencing using Illumina NovaSeq 6000 platform. This case control study reports significant association between BC patients, healthy controls with the polymorphic variants of PI3K C > T, AKT-1 G > A KLF 14 C > T, MDM4 A > G, miR-27a A > G, miR-196a-2 C > T genes (p < 0.05). MDM4 A > G genotypes were strongly associated with BC predisposition with OR 2.08 & 2.15, p < 0.05) in codominant and dominant models respectively. MDM4 A allele show the same effective (OR1.76, p < 0.05) whereas it remains protective in recessive model for BC risk. AKT1G > A genotypes were strongly associated with the BC susceptibility in all genetic models whereas PI3K C > T genotypes were associated with breast cancer predisposition in recessive model OR 6.96. Polymorphic variants of KLF-14 A > G, MDM4G > A, MiR-27aA >G, miR-196a-C > T were strongly associated with stage, tamoxifen treatment. Risk variants have been reported by whole exome sequencing in our BC patients. It was concluded that a strong association between the PI3K-AKT signaling pathway gene variants with the breast cancer susceptibility and progression. Similarly, KLF 14-AA, MDM4-GA, miR27a-GG and miR-196a-CT gene variants were associated with the higher risk probability of BC and were strongly correlated with staging of the BC patients. This study also reported Low, novel, and intermediate-genetic-risk variants of PI3K, AKT-1, MDM4G & KLF-14 by utilizing whole-exome sequencing. These variants should be further investigated in larger cohorts' studies. [ABSTRACT FROM AUTHOR]

PPP2R1A-related neurodevelopmental disorder (NDD) is expressed with autosomal dominant inheritance and is typically caused by a pathogenic de novo PPP2R1A mutation. It is characterized by the predominant features of hypotonia, developmental delay, moderate-to-severe intellectual disability, agenesis of corpus callosum (ACC), ventriculomegaly, and dysmorphic features; however, none of these anomalies have been diagnosed prenatally. We report on the prenatal diagnosis of PPP2R1A-related NDD in two fetuses by whole exome sequencing. Fetus 1 had partial ACC and severe lateral ventriculomegaly; the pathogenic heterozygous c.544C > T (p. Arg182Trp) de novo missense variant in PPP2R1A was detected. Fetus 2 had severe enlargement of the lateral and third ventricles and macrocephaly; they showed a heterozygous likely pathogenic mutation in PPP2R1A gene (c.547C > T, p. Arg183Trp). Both variants were de novo. This was the first study to use trio WES to prenatally analyze fetuses with PPP2R1A variants. Prenatal diagnosis will not only expand the fetal phenotype of this rare genetic condition but also allow for an appropriate counseling of prospective parents regarding pregnancy outcomes. [ABSTRACT FROM AUTHOR]

Objective: To study the etiology of congenital hydrocephalus in genetic aqueduct stenosis. Case report: We report the case of a 31-year-old pregnant female, G2P0A1, with a history of hyperthyroidism under medical control. The patient received regular prenatal care, with no specific findings in the Level II ultrasound at 21 weeks of gestation. However, hydrocephalus was noted at GA 31 weeks. High-resolution sonography and fetal magnetic resonance imaging (MRI) reported fetal aqueduct stenosis. Maternal HSV, CMV, and toxoplasma infection were not detected. Fetal karyotype and chromosomal microarray analysis (CMA) indicated a normal. After intensive counseling, the parents decided to terminate the pregnancy due to the poor fetal prognosis. Post-mortem, a whole-exome sequencing (WES) and Sanger sequencing analysis trio study identified two compound heterozygous variants in the POMT2 gene inherited from both recessive parents. In the subsequent pregnancy, a WES survey revealed inheritance of only the maternal POMT2 gene variant; a live, healthy male baby was born. Conclusion: Extended WES represents a precision maternal medicine tool for novel prenatal diagnosis of congenital aqueduct stenosis.

Background: Infection-associated acute encephalopathy (AE) is a clinical condition caused by a variety of pathogens, particularly common viruses. In some cases, this condition could be characterized by a sudden onset and a rapid progression, leading to severe neurological sequelae, including acute encephalopathy with biphasic seizures and late reduced diffusion, hemorrhagic shock and encephalopathy syndrome, etc. Case presentation: In this study, it was reported that three previously healthy children developed acute encephalopathy/encephalitis symptoms with different neurological sequelae after either Influenza A Virus or Human Herpesvirus 1 infection, presenting with fever and convulsions. What's more, after performing the gene exon detection for these three children, it was found that there are abnormal genes corresponding to their neurological sequelae, including SLC25A19 and TICAM1. Conclusions: Therefore, comparing to children with common encephalitis, for children with encephalitis whose progression is rapid and clinical manifestations such as recurrent fever and frequent convulsions is difficult to improve, whole-exome sequencing can be a valuable tool for identifying encephalitis-associated genetic variants and providing strong evidence for prognostic prediction.

Background: Central nervous system candidiasis due to Candida albicans (CNSC) in children is easily misdiagnosed and is associated with poor outcomes and a high mortality rate. There is no big data research or systematic review of CNSC. Methods: Patients diagnosed as CNSC with positive culture results of Candida albicans in Beijing Children's Hospital affiliated to Capital Medical University from March 2010 to March 2019 were included. Patients receiving immunosuppressive therapy or transplantation, or with malignant tumours were excluded. We analysed the clinical characteristics, follow-up results, drug susceptibility tests and whole-exome sequencing (WES) results. Results: Thirty-three definitive patients were enrolled, including 22 males and 11 females. Twenty-five patients suffered from CNSC when they were less than 1 year old, and a total of 29 patients had high-risk factors. The main clinical manifestations were fever, convulsions, and positive neurological signs. Twenty-two patients had CNS infections alone, and 11 patients had CNS infections combined with invasive infections involving multiple sites. Twenty-seven cases had a positive CSF and/or blood culture at our hospital. All strains were susceptible to fluconazole, and 2 strains had intermediate susceptibility to voriconazole. As for amphotericin B, all the strains were wild type (WT). WES of 16 patients revealed 2 cases with CARD9 mutations, who suffered from recurrent onychomycosis or thrush before. Conclusion: CNSC mostly existed in children younger than 1 year old, who all had underlying risk factors. CNSC patients with onset at an older age or with recurrent superficial fungal infections might have primary immunodeficiency. [ABSTRACT FROM AUTHOR]

Heterozygous pathogenic variants in DNM1 are linked to an autosomal dominant form of epileptic encephalopathy. Recently, homozygous loss-of-function variants in DNM1 were reported to cause an autosomal recessive form of developmental and epileptic encephalopathy in unrelated patients. Here, we investigated a singleton from a first-degree cousin marriage who presented with facial dysmorphism, global developmental delay, seizure disorder, and nystagmus. To identify the involvement of any likely genetic cause, diagnostic clinical exome sequencing was performed. Comprehensive filtering revealed a single plausible candidate variant in DNM1. Sanger sequencing of the trio, the patient, and her parents, confirmed the full segregation of the variant. The variant is a deletion leading to a premature stop codon and is predicted to cause a protein truncation. Structural modeling implicated a complete loss of function of the Dynamin 1 (DNM1). Such mutation is predicted to impair the nucleotide binding, dimer formation, and GTPase activity of DNM1. Our study expands the phenotypic spectrum of pathogenic homozygous loss-of-function variants in DNM1. [ABSTRACT FROM AUTHOR]

Congenital absence of the vas deferens (CAVD) is a major cause of obstructive azoospermia. Mutations of CFTR and ADGRG2 cause the majority of CAVD. Despite this, 10%--20% of CAVD patients remain without a clear genetic diagnosis. Herein, the CFTR and ADGRG2 genes were first sequenced using Sanger sequencing in 50 CAVD patients. Whole-exome sequencing (WES) was used to further identify potential novel genetic causes in CAVD with hypospadias. In total, 29 of 50 CAVD patients carried at least one CFTR mutation, but no ADGRG2 mutation was found. 5T was found to be the most frequent variant in our CAVD populations. Seven CAVD patients with hypospadias were further analyzed using WES. No homozygous or compound heterozygous mutations related to disorders of sex development (DSDs) or male infertility were identified by WES. CAVD with hypospadias presented lower testicular volume (9.71 ± 2.14 ml vs. 14.45 ± 2.93 ml, p < 0.001) and higher FSH level (FSH: 7.28 ± 3.91 IU/L vs. 4.24 ± 1.96 IU/L, p = 0.027) than CAVD without hypospadias. It is worth noting that neither CFTR or ADGRG2 mutation nor homozygous or compound heterozygous gene mutations were identified in seven CAVD cases with hypospadias. However, nine heterozygous or hemizygous mutations were selected as potential pathogenic genes in CAVD with hypospadias. In conclusion, CFTR variants, especially 5T, play a major role in the Chinese CAVD population. CAVD with hypospadias shows relatively lower testicular spermatogenesis, suggesting a different genetic basis or pathogenic factor from cystic fibrosis/CAVD or unilateral renal agenesis/ CAVD. [ABSTRACT FROM AUTHOR]

Fibrochondrogenesis 1, an autosomal recessive syndrome, is a rare disease that causes short‐limbed skeletal dysplasia. Mutations in the gene encoding the α1 chain of type XI collagen (COL11A1) are seen to be the main cause of this disease. We present an 18‐week Iranian male aborted fetus with Fibrochondrogenesis 1 from consanguineous parents. Whole‐exome sequencing revealed a novel missense variant from G to A in exon 45 of 68 in the COL11A1 gene (NM_080629.2: c.3440G > A, [p.G1147E, g.103404625]). The mutation was confirmed by Sanger sequencing and further, MutationTaster predicted this variant to be disease‐causing. Bioinformatic analysis suggests that this variant is highly conserved in both nucleotide and protein levels, suggesting that it has an important function in the proper role of COL11A1 protein. In silico analysis suggests that this mutation alters the COL11A1 protein structure through a Glycine to Glutamic acid substitution. A missense variant from G to A in exon 45 of 68 in the COL11A1 gene (NM_080629.2: c.3440G > A, [p.G1147E, g.103404625]) is a novel pathogenic mutation that is associated with Fibrochondrogenesis 1. [ABSTRACT FROM AUTHOR]

Congenital cataracts (CCs) have significant genotypic and phenotypic heterogeneity. The major intrinsic protein (MIP) gene, one of the causative genes of CCs, plays a vital role in maintaining the homeostasis and transparency of the lens. In this study, we identified a unique phenotype of anterior umbilication of the lens in a four-generation pedigree with CCs. All patients in the observed family had nystagmus, nuclear cataracts, and elongated axial lengths compared with their healthy counterparts except for patient I:2, whose axial length was unavailable, and patientII:4, who had total cataracts. We confirmed, using Sanger sequencing based on whole-exon sequencing (WES) data, that all patients carried a heterozygous variant NM_012064.4:c.97C > T (NP_036196.1:p.R33C) in their MIP gene. To our knowledge, 29 variants of the human MIP gene and the relative phenotypes associated with CCs have been identified. Nevertheless, this is the first report on the anterior umbilication of the lens with nuclear or total opacity caused by the c.97C > T (p.R33C) variant in the MIP gene. These results also provide evidence that the elongated axial length might be associated with this variant. This study further confirms the phenotypic heterogeneity of CCs. [ABSTRACT FROM AUTHOR]

Inborn errors of immunity are known to influence susceptibility to mycobacterial infections. The aim of this study was to characterize the genetic profile of nine patients with mycobacterial infections (eight with BCGitis and one with disseminated tuberculosis) from the Republic of Moldova using whole-exome sequencing. In total, 12 variants in eight genes known to be associated with Mendelian Susceptibility to Mycobacterial Disease (MSMD) were detected in six out of nine patients examined. In particular, a novel splice site mutation c.373-2A>C in STAT1 gene was found and functionally confirmed in a patient with disseminated tuberculosis. Trio analysis was possible for seven out of nine patients, and resulted in 23 candidate variants in 15 novel genes. Four of these genes - GBP2, HEATR3, PPP1R9B and KDM6A were further prioritized, considering their elevated expression in immune-related tissues. Compound heterozygosity was found in GBP2 in a single patient, comprising a maternally inherited missense variant c.412G>A/p.(Ala138Thr) predicted to be deleterious and a paternally inherited intronic mutation c.1149+14T>C. Functional studies demonstrated that the intronic mutation affects splicing and the level of transcript. Finally, we analyzed pathogenicity of variant combinations in gene pairs and identified five patients with putative oligogenic inheritance. In summary, our study expands the spectrum of genetic variation contributing to susceptibility to mycobacterial infections in children and provides insight into the complex/oligogenic diseasecausing mode. [ABSTRACT FROM AUTHOR]

Dilated cardiomyopathy (DCM) is a complex disease affecting young adults. It is a pathological condition impairing myocardium activity that leads to heart failure and, in the most severe cases, transplantation, which is currently the only possible therapy for the disease. DCM can be attributed to many genetic determinants interacting with environmental factors, resulting in a highly variable phenotype. Due to this complexity, the early identification of causative gene mutations is an important goal to provide a genetic diagnosis, implement pre-symptomatic interventions, and predict prognosis. The advent of next-generation sequencing (NGS) has opened a new path for mutation screening, and exome sequencing provides a promising approach for identifying causal variants in known genes and novel disease-associated candidates. We analyzed the whole-exome sequencing (WES) of 15 patients affected by DCM without overloading (hypertension, valvular, or congenital heart disease) or chronic ischemic conditions. We identified 70 pathogenic or likely pathogenic variants and 1240 variants of uncertain clinical significance. Gene ontology enrichment analysis was performed to assess the potential connections between affected genes and biological or molecular function, identifying genes directly related to extracellular matrix organization, transcellular movement through the solute carrier and ATP-binding cassette transporter, and vitamin B12 metabolism. We found variants in genes implicated to a different extent in cardiac function that may represent new players in the complex genetic scenario of DCM. [ABSTRACT FROM AUTHOR]