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Introduction: Hereditary spherocytosis (HS) is a common hereditary hemolytic anemia characterized by chronic hemolysis, increased indirect serum bilirubin, the presence of reticulocytes and spherocytes in blood smears, and great heterogeneity at the clinical, biochemical, and molecular levels. The molecular pathology of HS includes genetic variants at five genes: ANK1 , EPB42 , SLC4A1 , SPTA1 , and SPTB . Alpha spectrin ( SPTA1 ) deficiency is the second leading cause of HS in Mexican patients. Aim: To assess the effects of five SPTA1 variants on the hematological phenotype of Mexican patients with HS. Materials and Methods: This study included a retrospective cohort of 227 biologically unrelated patients with HS. Variants c.4339-99C>T and c.6531-12C>T in SPTA1 were identified by the amplification-refractory mutation system polymerase chain reaction (ARMS-PCR), and variants c.5572C>T, c.5992C>G, and c.6794T>C were identified by quantitive Real Time-Polymerase Chain Reaction (qRT-PCR) allelic discrimination. Risk tests were performed for each variant with respect to HS clinical severity. Results: The SPTA1 c.5992C>G variant showed association with moderately severe HS ( p  = 0.006, odds ratio = 5.67, confidence interval 95%  = 1.6-19.9); the risk increased when the variant was in compound heterozygosity with α LELY and c.6794T>C. Lower hematological levels were observed in simple α Lely (c.5572C>T and c.6531-12C>T), and c.5992C>G heterozygotes (red blood cell [RBC] p  = 0.028 and 0.010; hemoglobin [Hb] p  = 0.030 and 0.002; packed cell volume [PCV] p  = 0.034 and 0.002 respectively), and in c.5992C>G+c.6794T>C compound heterozygotes (RBC p  = 0.043; Hb p  = 0.033; PCV p  = 0.043). Additional genetic traits were observed: 15% had HS+Gilbert syndrome and 13% HS+thalassemia. Conclusion: Although most of the studied variants are considered benign, we observed significant associations with phenotypic severity. Therefore, we recommend the inclusion of these variants in molecular screening for HS.

Sialidosis is a rare autosomal recessive disease that presents with progressive lysosomal storage of sialylated glycopeptides and oligosaccharides caused by homozygous or compound heterozygous sequence variants in the neuraminidase 1 ( NEU1 ) gene. These sequence variants can lead to sialidosis type I and II; the latter is the most severe and presents prenatally or at early age. However, sialidosis diagnosis is challenging, especially in those health systems with limited resources of developing countries. Consequently, it is necessary to dip into high-throughput molecular diagnostic tools to allow for an accurate diagnosis with better cost-effectiveness and turnaround time. We report a 4-member pedigree segregating an ultrarare missense variant, c.1109A>G; p.Tyr370Cys, in NEU1 as detected by whole-exome sequencing. Two short-lived siblings, who presented with previously unreported clinical features from such a homozygous sequence variant, were diagnosed with sialidosis type II. Additionally, we present a novel molecular model exhibiting the consequences of the variant in the sialidase-1 tridimensional structure. This study allowed us to provide a definitive diagnosis for our patients, increase our understanding of this pathogenic variant, and improve genetic counseling., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2021 by S. Karger AG, Basel.)

Microcephaly is defined by an occipital-frontal head circumference (OFD) 2 standard deviations (SD) smaller than the average expected for age, gender and population. Its incidence has been reported between 1.3 and 150 cases per 100,000 births. Currently, new clinical characteristics, causes and pathophysiological mechanisms related to microcephaly continue to be identified. Its etiology is varied and heterogeneous, with genetic and non-genetic factors that produce alterations in differentiation, proliferation, migration, repair of damage to deoxyribonucleic acid and neuronal apoptosis. It requires a multidisciplinary diagnostic approach that includes a medical history, detailed prenatal and postnatal clinical evaluation, cerebral magnetic resonance imaging, neuropsychological evaluation, and in some cases complementary tests such as metabolic screening, tests to rule out infectious processes and genetic testing. There is no specific treatment or intervention to increase cerebral growth; however, timely intervention strategies and programs can be established to improve motor and neurocognitive development, as well as to provide genetic counseling. The objective of this work is to review the available information and reinforce the proposal to carry out an etiopathogenic approach for microcephaly diagnosis and management., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2021. Published by Elsevier B.V.)

Blau syndrome (BS) is a rare, chronic autoinflammatory disease with onset before age 4 and mainly characterised by granulomatous arthritis, recurrent uveitis, and skin rash. Sporadic (also known as early-onset sarcoidosis) or familial BS is caused by gain-of-function mutations in the NOD2 gene, which encodes for a multi-task protein that plays a crucial role in the innate immune defense. We report on three Mexican patients clinically diagnosed with BS who exhibited a likely pathogenic variant in NOD2 as revealed by whole-exome sequencing (WES) and Sanger sequencing: two variants (c.1000 C > T/p.Arg334Trp and c.1538 T > C/p.Met513Thr) lie in the ATP/Mg2+ binding site, whereas the other (c.3019dupC/p.Leu1007ProfsTer2) introduces a premature stop codon disrupting the last LRR domain (LRR9) formation; all three variants are consistent with gain-of-function changes. Interestingly, all these patients presented concomitant likely pathogenic variants in other inflammatory disease-related genes, i.e. TLR10 , PRR12 , MEFV and/or SLC22A5 . Although the clinical presentation in these patients included the BS diagnostic triad, overall it was rather heterogeneous. It is plausible that this clinical variability depends partly on the patients' genetic background as suggested by our WES results. After this molecular diagnosis and given the absence of NOD2 mutations (demonstrated in two trios) and related symptoms in the respective parents (confirmed in all trios), patients 1 and 2 were considered to have sporadic BS, while patient 3, a sporadic BS-recurrent polyserositis compound phenotype. Altogether, our observations and findings underscore the overlapping among inflammatory diseases and the importance of determining the underlying genetic cause by high-throughput methods. Likewise, this study further reinforces a pathogenic link between the here found NOD2 variants and BS and envisages potential additive effects from other loci in these, and probably other patients.

Amniotic bands sequence is a congenital disorder characterized by craniofacial, body wall, and limb anomalies that may be associated with fetalplacental fibrous bands. Its prevalence has been reported to range from 0.19 to 8.1 per 10 000 births. Different theories have attempted to explain the etiology of amniotic band sequence; however, none has individually been able to support each and every defect observed, so it has been considered to be a multifactorial condition. The (pre- and post-natal) identification of anomalies suggestive of amniotic band sequence is useful for the diagnostic approach and implementation of timely therapeutic interventions favoring the release of the amniotic bands using fetoscopy with recovery of the involved distal limb perfusion, or else the possibility of performing a post-natal surgical repair. It is also helpful to provide genetic counseling. This article offers an update on the epidemiological aspects, etiological theories, risk factors, clinical characteristics, diagnosis (including antenatal diagnosis), genetic counseling, therapeutic approach, and prognosis of amniotic bands sequence., (Sociedad Argentina de Pediatría.)

We describe a patient severely affected with multiple congenital anomalies, including brain malformations and skeletal dysplasia suggestive of cranioectodermal dysplasia (CED) ciliopathy, who unusually carries several homozygosity tracts involving homozygous missense mutations in SPAG17 (exon 8; c.1069G > C; p.Asp357His) and WDR35 (exon 13; c.1415G > A; p.Arg472Gln) as revealed by homozygosity mapping and next generation sequencing. SPAG17 is essential for the function and structure of motile cilia, while WDR35 belongs to the same intraflagellar transport (IFT) gene family whose protein products are part of functional IFT A and B complexes. Formerly, SPAG17 was related - through polymorphic variants - to an influence on individuals' height; more recently, Spag17-/- mice models were reported to present skeletal and bone defects, reduced mucociliary clearance, respiratory distress, and cerebral ventricular enlargement. Homozygous or compound heterozygous mutations in WDR35 have mainly been related to CED2 or short-rib thoracic dysplasia 7, with only three cases showing some brain anomalies. Given that our patient presents these clinical features and the close functional relationship between SPAG17 and WDR35, it is feasible that the combined effects from both mutations contribute to his phenotype. To our knowledge, this patient is the first to harbor a likely pathogenic homozygous mutation in both genes at the same time. Thus, the resulting complex phenotype of this patient illustrates the heterogeneity associated with ciliopathies and further expands the clinical and mutational spectrum of these diseases. Finally, we highlight the combined use of high-throughput tools to diagnose and support the proper handling of this and other patients., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Background: Disruptive amniotic band sequence (DABS) is a sporadic, non-familial disorder with unclear etiology. Diagnosis is based on clinical features because there is currently no reliable laboratory diagnostic tests., Objective: We describe six cases of DABS with severe craniofacial deformations, three with and three without classical constrictive limb deformation., Results: The craniofacial deformities were delimited by peripheral sharply demarcated scarring., Conclusion: When a sharply demarcated linear disruptive craniofacial lesion is observed, DABS should be considered despite the absence of constrictive limb scarring.

The association of anophthalmia, arrhinia, and hypogonadism constitutes the major clinical features for Bosma arrhinia microphthalmia syndrome. However, there is variability in the presentation of this disease; arrhinia is the most constant clinical feature, which is then combined with a spectrum of anophthalmia/microphthalmia and/or hypogonadism. This rare entity is not associated with any specific genes, but the genes that are related to arrhinia and anophthalmia have been studied in an attempt to explain this phenomenon. We analyzed the PAX6 gene in a Bosma arrhinia microphthalmia syndrome patient but found no variation or mutation that could constitute or establish a causal association in our patient.

Spondylospinal thoracic dysostosis can be considered a type of spondylocostal dysostosis because of the occurrence of vertebral defects (hemivertebrae and vertebral body fusion) and thoracic anomalies (short thorax and pulmonary hypoplasia). This syndrome was described by Johnson et al. (1997) in two siblings with dwarfism, short thorax, curved spine, fusion of the vertebrae and spinal process, multiple pterygium, and arthrogryposis. We describe the case of a 16-year-old Mexican girl with the longest survival recorded (the previous oldest patient was 7 years old) and analyze the natural history and describe some new features of this rare entity.

Macrocephaly can be found isolated or associated with other anomalies as a part of specific syndrome. Benign Familial Macrocephaly (BFM) is a primary macrocephaly and autosomal dominant and multifactorial inheritances had been proposed. Cole and Hughes (5), described clinically seven patients. We report two BFM cases, a boy and his mother. The male propositus showed macrocephaly with dolicocephaly shape, frontal bossing, narrowing biparietal and a square-shaped face. Neurological examination was normal. He had two computed tomography (CT) scans of the skull, one at 7 months of age showing extracerebral fluid collection in the anterior convexity and increased interhemispheric subarachnoid space and a second normal CT scan at 3 years of age. The mother showed macrocephaly with dolycocephaly shape and dished-out mid-face. This family exhibited the full clinical spectrum of BFM, with an autosomal dominant inheritance.

Snyder-Robinson syndrome (SRS, OMIM 309583) is a rare X-linked syndrome characterized by mental retardation, marfanoid habitus, skeletal defects, osteoporosis, and facial asymmetry. Linkage analysis localized the related gene to Xp21.3-p22.12, and a G-to-A transition at point +5 of intron 4 of the spermine synthase gene, which caused truncation of the SMS protein and loss of enzyme activity, was identified in the original family. Here we describe another family with Snyder-Robinson syndrome in two Mexican brothers and a novel mutation (c.496T>G) in the exon 5 of the SMS gene confirming its involvement in this rare X-linked mental retardation syndrome., (2009 Wiley-Liss, Inc.)

We report the fifth female patient with Myhre syndrome (MS) and review the literature. She is a 13-year-old Mexican girl whose phenotype fulfills all the clinical and radiological criteria reported in MS such as typical facies, short stature, limited joint mobility, and short hands and feet. The physical habitus of MS is described and a square body shape is clearly distinguished in all cases. As the typical muscular build is present mainly in male patients, the MS muscular appearance may be hormonally influenced.

Mesomelic dysplasias (MD) are a group of skeletal disorders with exclusive or predominant shortness of the middle segment of the limbs, with or without involvement of the hands/feet or other body parts. Short stature is a usual consequence due to involvement of the lower limbs. In 2003, Camera and Camera reported an unusual upper limb MD with normal stature and radiological evidence of long bone metaphyseal dysplasia. Here, we describe a Mexican patient showing a similar clinical and radiological phenotype, in addition to esophageal atresia, palpebral ptosis and slight lower limb asymmetry. This represents the second case reported in the literature, corroborating the existence of this rare entity.

A 25-year-old woman with a mosaic 45,X/47XX,+14 karyotype is reported. She presented with short stature, short downward slanting palpebral fissures, broad nasal bridge, mouth with downturned corners, short and wide neck, swirly hyperpigmentation of the skin, and body asymmetry secondary to right hemihyperplasia. As there was an admixture of 45,X and trisomy 14, it was not possible to determine the cell line that had the greatest influence on the phenotype. We postulate that the proposita's survival until the third decade was owing to the chromosomal complementation of both aneuploidy cell lines. To our knowledge, this chromosomal association has not been previously reported.

We report on a 3-year-old girl with a typical 9p trisomy syndrome, whose 45-chromosome karyotype includes a 9p+. As assessed by G, C and Ag-NOR bands, the rearranged chromosome resulted from a 9p13-->p24 direct duplication coupled with a translocation of the whole 22q onto 9pter, had heterochromatin at the junction site, lacked both nucleolar organizing regions (NORs) and centromere dots at the unconstricted fusion point, and was present in all metaphases scored. FISH results: a 9p subtelomere probe gave a diminished signal on the 9p+ precisely at the duplication junction 9p24::9p13, but no labeling was observed at the 9;22 translocation site; a pancentromeric alphoid probe labeled all centromeres, and gave a distinct signal at the 9pter;22cen junction. Hence, her karyotype was 45,XX,rea(9;22)(9qter-->9p24::9p13-->9p24::22p10-->22qter).ish rea(9;22) (9psubtel+dim,pancen+). Parental chromosomes were normal. The distinctiveness of the present centromere-telomere fusion rests on the coupling of an intrachromosomal distal duplication with a whole-arm translocation including alphoid DNA onto the duplicated segment. The centromeric inertia of the residual alphoid DNA in the present case compares with the variable functional status of the chromosome 22 centromere in true heterodicentrics involving such a chromosome.

We describe a father-son Mexican pair with typical features of Schilbach-Rott syndrome (SRS): ocular hypotelorism, cleft palate, hypospadias (only in the child), and microcephaly. This observation documents for the first time a male to male transmission and therefore confirms that the SRS is inherited as an autosomal dominant trait with variable expressivity.