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PURPOSE: Adducins interconnect spectrin and actin filaments to form polygonal scaffolds beneath the cell membranes, and form ring-like structures in neuronal axons. Adducins regulate mouse neural development, but their function in the human brain is unknown. METHODS: We used exome sequencing to uncover ADD1 variants associated with intellectual disability (ID) and brain malformations. We studied ADD1 splice isoforms in mouse and human neocortex development with RNA Sequencing, super resolution imaging and immunoblotting. We investigated four variant ADD1 proteins and heterozygous ADD1 cells for protein expression and ADD1-ADD2 dimerization. We studied Add1 functions in vivo using Add1 knockout mice. RESULTS: We uncovered loss-of-function (LoF) ADD1 variants in four unrelated individuals affected by ID and/or structural brain defects. Three additional de novo copy number variations covering the ADD1 locus were associated with ID and brain malformations. ADD1 is highly expressed in the neocortex and the corpus callosum, while ADD1 splice isoforms are dynamically expressed between cortical progenitors and postmitotic neurons. Human variants impair ADD1 protein expression and/or dimerization with ADD2. Add1 knockout mice recapitulate corpus callosum dysgenesis and ventriculomegaly phenotypes. CONCLUSION: Our human and mouse genetics results indicate that pathogenic ADD1 variants cause corpus callosum dysgenesis, ventriculomegaly, and/or intellectual disability.

Purpose Hardikar syndrome (MIM 612726) is a rare multiple congenital anomaly syndrome characterized by facial clefting, pigmentary retinopathy, biliary anomalies, and intestinal malrotation, but with preserved cognition. Only four patients have been reported previously, and none had a molecular diagnosis. Our objective was to identify the genetic basis of Hardikar syndrome (HS) and expand the phenotypic spectrum of this disorder. Methods We performed exome sequencing on two previously reported and five unpublished female patients with a clinical diagnosis of HS. X-chromosome inactivation (XCI) studies were also performed. Results We report clinical features of HS with previously undescribed phenotypes, including a fatal unprovoked intracranial hemorrhage at age 21. We additionally report the discovery of de novo pathogenic nonsense and frameshift variants in MED12 in these seven individuals and evidence of extremely skewed XCI in all patients with informative testing. Conclusion Pathogenic missense variants in the X-chromosome gene MED12 have previously been associated with Opitz-Kaveggia syndrome, Lujan syndrome, Ohdo syndrome, and nonsyndromic intellectual disability, primarily in males. We propose a fifth, female-specific phenotype for MED12, and suggest that nonsense and frameshift loss-of-function MED12 variants in females cause HS. This expands the MED12-associated phenotype in females beyond intellectual disability.

The RASopathies are a group of similar genetic syndromes with cardiovascular abnormalities, characteristic facial features, short stature, abnormalities of the skin and musculoskeletal system, and variable neurodevelopmental challenges. The most common cardiovascular abnormalities include pulmonary valvular stenosis and hypertrophic cardiomyopathy. Congenital polyvalvular disease (CPVD) refers to congenital dysplasia of two or more cardiac valves. We diagnosed a RASopathy in two individuals with CPVD and noted that CPVD in RASopathies has rarely been reported in the literature. Thus, we performed a retrospective chart review and literature review to investigate the association and characterize the phenotype of CPVD in the RASopathies. CPVD was present in 2.5% (n = 6/243) of individuals in our RASopathy cohort. Involvement of two cardiac valves, commonly the aortic and pulmonic valves, was seen in the majority of individuals (6/8; 75%) in our cohort, but only 27% (3/11) of reported CPVD and RASopathy cases in the literature. CPVD should be considered an associated cardiovascular phenotype of the RASopathies, which has implications for diagnosis and management.

Genodermatoses are inherited disorders with skin manifestations and can present with multisystem involvement, resulting in challenges in diagnosis and treatment. To address this, the expertise of dermatology and clinical genetics through a multidisciplinary clinic (Genodermatoses Clinic) were combined. A retrospective cohort study of 45 children seen between March 2018 and February 2019 in the Genodermatoses Clinic at The Children's Hospital of Philadelphia was performed. Patient demographics, referral information, genetic testing modality, diagnoses, and patient satisfaction scores were evaluated to assess the clinic's impact. The majority of patients (42.2%) were referred from Dermatology and 86.7% were referred for diagnosis. Two-thirds of the patients were recommended genetic testing, and subsequently 73.3% completed testing. Nearly three-quarters, 26 out of 36 patients (72.2%), of our undiagnosed patients received a clinical and/or molecular diagnosis, which is imperative in managing their care. Twenty-two individuals pursued genetic testing. In eight individuals (36%), molecular testing was diagnostic. However, in two individuals the molecular diagnosis did not completely explain the phenotype. However, there are still obstacles to genetic testing, such as cost of testing and insurance barriers. Almost all (91.4%) rated the Genodermatoses Clinic as "Very Good," the top Press Ganey score. High patient satisfaction scores suggest a positive impact of the Genodermatoses clinic, emphasizing the importance to increase support for the clinical and administrative time needed for patients with genodermatoses.

We describe our experiences with organizing pro bono medical genetics and neurology outreach programs on several different resource-limited islands in the West Indies. Due to geographic isolation, small population sizes, and socioeconomic disparities, most Caribbean islands lack medical services for managing, diagnosing, and counseling individuals with genetic disorders. From 2015 to 2019, we organized 2-3 clinics per year on various islands in the Caribbean. We also organized a week-long clinic to provide evaluations for children suspected of having autism spectrum disorder. Consultations for over 100 different individuals with suspected genetic disorders were performed in clinics or during home visits following referral by locally registered physicians. When possible, follow-up visits were attempted. When available and appropriate, clinical samples were shipped to collaborating laboratories for molecular analysis. Laboratory tests included karyotyping, cytogenomic microarray analysis, exome sequencing, triplet repeat expansion testing, blood amino acid level determination, biochemical assaying, and metabolomic profiling. We believe that significant contributions to healthcare by genetics professionals can be made even if availability is limited. Visiting geneticists may help by providing continuing medical education seminars. Clinical teaching rounds help to inform local physicians regarding the management of genetic disorders with the aim of generating awareness of genetic conditions. Even when only periodically available, a visiting geneticist may benefit affected individuals, their families, their local physicians, and the community at large.

A range of clinical findings have been associated with heterozygous mutations in the Beta Tubulin (TUBB) gene, including microcephaly, structural brain abnormalities, intellectual disability, and skin creases. We report a 5-year-old male who presented for evaluation of cleft palate, cardiac defects, growth retardation, hemivertebrae causing scoliosis, and preauricular skin tags. Previous clinical exome sequencing of this patient was nondiagnostic, but reanalysis in the research setting identified a de novo missense c. 925C>G p.(Arg309Gly) mutation in TUBB. This mutation was not found in population allele frequency databases, and was classified to be likely pathogenic. This patient shares some phenotypic characteristics with previous reported patients of TUBB mutations of the two TUBB-related phenotypes: "Cortical dysplasia, complex, with other brain malformations 6" [MIM 615771] and "Circumferential Skin Creases Kunze type (CSC-KT)" [MIM 156610], but has no excess skin creases or structural brain anomalies. We also report previously undescribed features, including transposition of the great arteries and vertebral fusion, thus representing phenotype expansion of TUBB-associated disorders.

NALCN encodes a sodium ion leak channel expressed in the nervous system that conducts a persistent influx of sodium ions to facilitate action potential formation. Homozygous or compound heterozygous loss of function variants in NALCN cause infantile hypotonia with psychomotor retardation and characteristic facies-1 (IHPRF1; OMIM 615419). Through exome and Sanger sequencing, we found two siblings of Afro-Caribbean ancestry who are homozygous for a known NALCN pathogenic variant, p.Arg735Ter, leading to failure to thrive, severe hypotonia, and dolichocephaly. The older sibling died suddenly without a known etiology after evaluation but before molecular diagnosis. An international collaboration originating from a resource limited Caribbean island facilitated molecular diagnosis. Due to its small population, geographical isolation, and low socioeconomic status, the island lacks many specialty medical services, including clinical genetics. Descriptions of genetic disorders affecting individuals of Afro-Caribbean ancestry are rarely reported in the medical literature. Diagnosis of IHPRF1 is important, as individuals with biallelic pathogenic NALCN variants are severely affected and potentially are at risk for cardiorespiratory arrest. Additionally, knowing the pathogenic variants allows the possibility of prenatal or preimplantation genetic diagnosis.

More than 50 individuals with activating variants in the receptor tyrosine kinase PDGFRB have been reported, separated based on clinical features into solitary myofibromas, infantile myofibromatosis, Penttinen syndrome with premature aging and osteopenia, Kosaki overgrowth syndrome, and fusiform aneurysms. Despite their descriptions as distinct clinical entities, review of previous reports demonstrates substantial phenotypic overlap. We present a case series of 12 patients with activating variants in PDGFRB and review of the literature. We describe five patients with PDGFRB activating variants whose clinical features overlap multiple diagnostic entities. Seven additional patients from a large family had variable expressivity and late-onset disease, including adult onset features and two individuals with sudden death. Three patients were treated with imatinib and had robust and rapid response, including the first two reported infants with multicentric myofibromas treated with imatinib monotherapy and one with a recurrent p.Val665Ala (Penttinen) variant. Along with previously reported individuals, our cohort suggests infants and young children had few abnormal features, while older individuals had multiple additional features, several of which appeared to worsen with advancing age. Our analysis supports a diagnostic entity of a spectrum disorders due to activating variants in PDGFRB. Differences in reported phenotypes can be dramatic and correlate with advancing age, genotype, and to mosaicism in some individuals.

Background De novo variants in the voltage-gated calcium channel subunit α1 E gene (CACNA1E) have been described as causative of epileptic encephalopathy with contractures, macrocephaly and dyskinesias. Methods Following the observation of an index patient with developmental delay and autism spectrum disorder (ASD) without seizures who had a de novo deleterious CACNA1E variant, we screened GeneMatcher for other individuals with CACNA1E variants and neurodevelopmental phenotypes without epilepsy. The spectrum of pathogenic CACNA1E variants was compared to the mutational landscape of variants in the gnomAD control population database. Results We identified seven unrelated individuals with intellectual disability, developmental regression and ASD-like behavioral profile, and notably without epilepsy, who had de novo heterozygous putatively pathogenic variants in CACNA1E. Age of onset of clinical manifestation, presence or absence of regression and degree of severity were variable, and no clear-cut genotype–phenotype association could be recognized. The analysis of disease-associated variants and their comparison to benign variants from the control population allowed for the identification of regions in the CACNA1E protein that seem to be intolerant to substitutions and thus more likely to harbor pathogenic variants. As in a few reported cases with CACNA1E variants and epilepsy, one patient showed a positive clinical behavioral response to topiramate, a specific calcium channel modulator. Limitations The significance of our study is limited by the absence of functional experiments of the effect of identified variants, the small sample size and the lack of systematic ASD assessment in all participants. Moreover, topiramate was given to one patient only and for a short period of time. Conclusions Our results indicate that CACNA1E variants may result in neurodevelopmental disorders without epilepsy and expand the mutational and phenotypic spectrum of this gene. CACNA1E deserves to be included in gene panels for non-specific developmental disorders, including ASD, and not limited to patients with seizures, to improve diagnostic recognition and explore the possible efficacy of topiramate.

Human genetic disorders, such as Down syndrome, have a wide variety of clinical phenotypic presentations, and characterizing each nuanced phenotype and subtype can be difficult. In this study, we examined the electronic health records of 4095 individuals with Down syndrome at the Children’s Hospital of Philadelphia to create a method to characterize the phenotypic spectrum digitally. We extracted Human Phenotype Ontology (HPO) terms from quality-filtered patient notes using a natural language processing (NLP) approach MetaMap. We catalogued the most common HPO terms related to Down syndrome patients and compared the terms with those from a baseline population. We characterized the top 100 HPO terms by their frequencies at different ages of clinical visits and highlighted selected terms that have time-dependent distributions. We also discovered phenotypic terms that have not been significantly associated with Down syndrome, such as “Proptosis”, “Downslanted palpebral fissures”, and “Microtia”. In summary, our study demonstrated that the clinical phenotypic spectrum of individual with Mendelian diseases can be characterized through NLP-based digital phenotyping on population-scale electronic health records (EHRs).

The advancement of precision medicine requires new methods to coordinate and deliver genetic data from heterogeneous sources to physicians and patients. The eMERGE III Network enrolled >25,000 participants from biobank and prospective cohorts of predominantly healthy individuals for clinical genetic testing to determine clinically actionable findings. The network developed protocols linking together the 11 participant collection sites and 2 clinical genetic testing laboratories. DNA capture panels targeting 109 genes were used for testing of DNA and sample collection, data generation, interpretation, reporting, delivery, and storage were each harmonized. A compliant and secure network enabled ongoing review and reconciliation of clinical interpretations, while maintaining communication and data sharing between clinicians and investigators. A total of 202 individuals had positive diagnostic findings relevant to the indication for testing and 1,294 had additional/secondary findings of medical significance deemed to be returnable, establishing data return rates for other testing endeavors. This study accomplished integration of structured genomic results into multiple electronic health record (EHR) systems, setting the stage for clinical decision support to enable genomic medicine. Further, the established processes enable different sequencing sites to harmonize technical and interpretive aspects of sequencing tests, a critical achievement toward global standardization of genomic testing. The eMERGE protocols and tools are available for widespread dissemination.

The treatment of lymphatic anomaly, a rare devastating disease spectrum of mostly unknown etiologies, depends on the patient manifestations1. Identifying the causal genes will allow for developing affordable therapies in keeping with precision medicine implementation2. Here we identified a recurrent gain-of-function ARAF mutation (c.640T>C:p.S214P) in a 12-year-old boy with advanced anomalous lymphatic disease unresponsive to conventional sirolimus therapy and in another, unrelated, adult patient. The mutation led to loss of a conserved phosphorylation site. Cells transduced with ARAF-S214P showed elevated ERK1/2 activity, enhanced lymphangiogenic capacity, and disassembly of actin skeleton and VE-cadherin junctions, which were rescued using the MEK inhibitor trametinib. The functional relevance of the mutation was also validated by recreating a lymphatic phenotype in a zebrafish model, with rescue of the anomalous phenotype using a MEK inhibitor. Subsequent therapy of the lead proband with a MEK inhibitor led to dramatic clinical improvement, with remodeling of the patient's lymphatic system with resolution of the lymphatic edema, marked improvement in his pulmonary function tests, cessation of supplemental oxygen requirements and near normalization of daily activities. Our results provide a representative demonstration of how knowledge of genetic classification and mechanistic understanding guides biologically based medical treatments, which in our instance was life-saving.

Congenital diaphragmatic hernias (CDH) confer substantial morbidity and mortality. Genetic defects, including chromosomal anomalies, copy number variants, and sequence variants are identified in ~30% of patients with CDH. A genetic etiology is not yet found in 70% of patients, however there is a growing number of genetic syndromes and single gene disorders associated with CDH. While there have been two reported individuals with X-linked Opitz G/BBB syndrome with MID1 mutations who have CDH as an associated feature, CDH appears to be a much more prominent feature of a SPECC1L-related autosomal dominant Opitz G/BBB syndrome. Features unique to autosomal dominant Opitz G/BBB syndrome include branchial fistulae, omphalocele, and a bicornuate uterus. Here we present one new individual and five previously reported individuals with CDH found to have SPECC1L mutations. These cases provide strong evidence that SPECC1L is a bona fide CDH gene. We conclude that a SPECC1L-related Opitz G/BBB syndrome should be considered in any patient with CDH who has additional features of hypertelorism, a prominent forehead, a broad nasal bridge, anteverted nares, cleft lip/palate, branchial fistulae, omphalocele, and/or bicornuate uterus.

Background Cornelia de Lange syndrome (CdLS) comprises a recognizable pattern of multiple congenital anomalies caused by variants of the DNA cohesion complex. Affected individuals may display a wide range of phenotypic severity, even within the same family. Methods Exome sequencing and confirmatory Sanger sequencing showed the same previously described p.Arg629Ter NIPBL variant in two half‐brothers affected with CdLS. Clinical evaluations were obtained in a pro bono genetics clinic. Results One brother had relatively mild proportionate limb shortening; the other had complete bilateral hypogenesis of the upper arm with absence of lower arm structures, terminal transverse defects, and no digit remnants. His complex lower limb presentation included long bone deficiency and a deviated left foot. The mother had intellectual disability and microcephaly but lacked facial features diagnostic of the CdLS. Conclusion We describe a collaboration between a pediatrics team from a resource‐limited nation and USA‐based medical geneticists. Reports describing individuals of West Indian ancestry are rarely found in the medical literature. Here, we present a family of Afro‐Caribbean ancestry with CdLS presenting with phenotypic variability, including unusual lower limb abnormalities. The observation of this novel family adds to our knowledge of the phenotypic and molecular aspects of CdLS., We found the same pathogenic NIPBL variant in two half‐brothers who are of Afro‐Caribbean ancestry. One of the brothers has a novel lower limb presentation.

Nucleoporins (NUPs) are an essential component of the nuclear-pore complex, which regulates nucleocytoplasmic transport of macromolecules. Pathogenic variants in NUP genes have been linked to several inherited human diseases, including a number with progressive neurological degeneration. We present six affected individuals with bi-allelic truncating variants in NUP188 and strikingly similar phenotypes and clinical courses, representing a recognizable genetic syndrome; the individuals are from four unrelated families. Key clinical features include congenital cataracts, hypotonia, prenatal-onset ventriculomegaly, white-matter abnormalities, hypoplastic corpus callosum, congenital heart defects, and central hypoventilation. Characteristic dysmorphic features include small palpebral fissures, a wide nasal bridge and nose, micrognathia, and digital anomalies. All affected individuals died as a result of respiratory failure, and five of them died within the first year of life. Nuclear import of proteins was decreased in affected individuals' fibroblasts, supporting a possible disease mechanism. CRISPR-mediated knockout of NUP188 in Drosophila revealed motor deficits and seizure susceptibility, partially recapitulating the neurological phenotype seen in affected individuals. Removal of NUP188 also resulted in aberrant dendrite tiling, suggesting a potential role of NUP188 in dendritic development. Two of the NUP188 pathogenic variants are enriched in the Ashkenazi Jewish population in gnomAD, a finding we confirmed with a separate targeted population screen of an international sampling of 3,225 healthy Ashkenazi Jewish individuals. Taken together, our results implicate bi-allelic loss-of-function NUP188 variants in a recessive syndrome characterized by a distinct neurologic, ophthalmologic, and facial phenotype.

Objective We describe the clinical characteristics and genetic etiology of several new cases within the ACO2‐related disease spectrum. Mitochondrial aconitase (ACO2) is a nuclear‐encoded tricarboxylic acid cycle enzyme. Homozygous pathogenic missense variants in the ACO2 gene were initially associated with infantile degeneration of the cerebrum, cerebellum, and retina, resulting in profound intellectual and developmental disability and early death. Subsequent studies have identified a range of homozygous and compound heterozygous pathogenic missense, nonsense, frameshift, and splice‐site ACO2 variants in patients with a spectrum of clinical manifestations and disease severities. Methods We describe a cohort of five novel patients with biallelic pathogenic variants in ACO2. We review the clinical histories of these patients as well as the molecular and functional characterization of the associated ACO2 variants and compare with those described previously in the literature. Results Two siblings with relatively mild symptoms presented with episodic ataxia, mild developmental delays, severe dysarthria, and behavioral abnormalities including hyperactivity and depressive symptoms with generalized anxiety. One patient presented with the classic form with cerebellar hypoplasia, ataxia, seizures, optic atrophy, and retinitis pigmentosa. Another unrelated patient presented with ataxia but developed severe progressive spastic quadriplegia. Another patient demonstrated a spinal muscular atrophy‐like presentation with severe neonatal hypotonia, diminished reflexes, and poor respiratory drive, leading to ventilator dependence until death at the age of 9 months. Interpretation In this study, we highlight the importance of recognizing milder forms of the disorder, which may escape detection due to atypical disease presentation.

Purpose :Genitopatellar syndrome and Say–Barber–Biesecker–Young–Simpson syndrome are caused by variants in the KAT6B gene and are part of a broad clinical spectrum called KAT6B disorders, whose variable expressivity is increasingly being recognized. Methods: We herein present the phenotypes of 32 previously unreported individuals with a molecularly confirmed diagnosis of a KAT6B disorder, report 24 new pathogenic KAT6B variants, and review phenotypic information available on all published individuals with this condition. We also suggest a classification of clinical subtypes within the KAT6B disorder spectrum. Results: We demonstrate that cerebral anomalies, optic nerve hypoplasia, neurobehavioral difficulties, and distal limb anomalies other than long thumbs and great toes, such as polydactyly, are more frequently observed than initially reported. Intestinal malrotation and its serious consequences can be present in affected individuals. Additionally, we identified four children with Pierre Robin sequence, four individuals who had increased nuchal translucency/cystic hygroma prenatally, and two fetuses with severe renal anomalies leading to renal failure. We also report an individual in which a pathogenic variant was inherited from a mildly affected parent. Conclusión: Our work provides a comprehensive review and expansion of the genotypic and phenotypic spectrum of KAT6B disorders that will assist clinicians in the assessment, counseling, and management of affected individuals. Sin financiación 8.822 JCR(2020) Q1, 15/176 Genetics & Heredity 3.509 SJR (2020) Q1, 7/96 Genetics (clinical) No data IDR 2020 UEM

Background: Facial asymmetry is a common referral indication for craniofacial teams but has a wide range of causes. Prompt identification of etiology is critical to treatment, as medical and surgical interventions vary depending on the cause of asymmetry in each patient. Solution: A standardized diagnostic algorithm. What We Did That Is New: We developed an algorithm to assist in the diagnostic evaluation of facial asymmetry with a focus on next steps for medically actionable causes.

The evaluation of the neonate with congenital anomalies has always been a vital and challenging task. In recent years, many advances and challenges have complicated the process, including noninvasive prenatal screening, Zika virus, assisted reproductive technology, and rapid exome sequencing. This review will provide a context for the general evaluation of a neonate with congenital anomalies, including adaptation of the most precise terminology, definition of major and minor anomalies, and the determination of whether the anomalies are the result of a sequence, deformation, disruption, or malformation. Practical tools, including a concise family history, nutritional implication, pregnancy history, and the effects of assisted reproductive technologies are also presented. With the advent of Zika virus–associated congenital anomalies, emphasis has also been placed on travel and infection exposures. A particular challenge has been the incorporation of both pre- and postnatal genetic screening and testing into a diagnostic framework. The most common tests will be reviewed, including the practical applications of both a positive and negative result in varying contexts. It has become clear that noninvasive prenatal screening and rapid exome sequencing are having an increasing impact on the evaluation of children with congenital anomalies, and their application and evaluation of their results will be reviewed in detail. The overarching goal of this review is to provide neonatal clinicians the tools to assess, contextualize, and discuss congenital anomalies in neonates to improve communication and the diagnostic process.

RASopathies include disorders generally characterized by developmental delay, specific heart defects, short stature, cardiac hypertrophy, and facial dysmorphisms. Next-generation sequencing (NGS)-based panels have widespread acceptance as a diagnostic tool for RASopathies. The first 126 patients evaluated by clinical examination and the NGS RASopathy panel at the Children’s Hospital of Philadelphia were enrolled. We calculated diagnosis rate, correlated reported clinical findings with positive or negative test results, and identified final molecular diagnoses in 28/96 patients who tested negative for RASopathies. Twenty-four patients had pathogenic variants on the RASopathy panel, for a diagnostic yield of 19%. Reported features of pulmonic stenosis and ptosis were significantly correlated with a positive test result; no reported features were significantly correlated with a negative test result. We identified 27 different alternative diagnoses for patients originally suspected of having RASopathies. This study provides information that can assist in guiding differential diagnosis and genetic testing for patients suspected of having a RASopathy disorder. Genet Med advance online publication 20 October 2016

Epidermolysis bullosa simplex (EBS) is a skin fragility disorder resulting from mutations of structural proteins in the epidermis. We provide a brief report of long-term survival and reproduction in a mother with EBS due to keratin 5 (KRT5) c.1429G > A (p.E477K) mutation, which causes a particularly severe form of the disease.

Muenke syndrome (MIM #602849), the most common syndromic craniosynostosis, results from the recurrent pathogenic p.P250R variant in FGFR3. Affected patients exhibit wide phenotypic variability. Common features include coronal craniosynostosis, hearing loss, carpal and tarsal anomalies, and developmental/behavioral issues. Our study examined the phenotypic findings, medical management, and surgical outcomes in a cohort of 26 probands with Muenke syndrome identified at the Children’s Hospital of Philadelphia. All probands had craniosynostosis; 69.7% had bicoronal synostosis only, or bicoronal and additional suture synostosis. Three male patients had autism spectrum disorder. Recurrent ear infections were the most common comorbidity, and myringotomy tube placement the most common extracranial surgical procedure. Most patients (76%) required only one fronto-orbital advancement. de novo mutations were confirmed in 33% of the families in which proband and both parents were genetically tested, while in the remaining 66% one of the parents was a mutation carrier. In affected parents, 40% had craniosynostosis, including 71% of mothers and 13% of fathers. We additionally analyzed the medical resource utilization of probands with Muenke syndrome. To our knowledge, these data represent the first comprehensive examination of long-term management in a large cohort of patients with Muenke syndrome. Our study adds valuable information regarding neuropsychiatric and medical comorbidities, and highlights findings in affected relatives.

Nevus comedonicus syndrome (NCS) is a rare epidermal nevus syndrome characterized by ocular, skeletal, and central nervous system anomalies. We present a 23-month-old boy with a history of a congenital pulmonary airway malformation (CPAM) of the lung and a congenital cataract who developed progressive linear and curvilinear plaques of dilated follicular openings with keratin plugs (comedones) on parts of his scalp, face, and body consistent with nevus comedonicus. MRI of the brain demonstrated an aneurysm of the right internal carotid artery. Genetic testing identified NEK9 c.1755_1757del (p.Thr586del) at mean allele frequency of 28% in the nevus comedonicus. This same mutation was present in the CPAM tissue. This is the first case of a CPAM in a patient with an epidermal nevus syndrome. This case expands the phenotype of nevus comedonicus syndrome to include CPAM and vascular anomalies.

The congenital myasthenic syndromes (CMS) are a heterogeneous group of disorders caused by perturbations in signal transduction at the neuromuscular junction. Defects in muscle, skeletal, receptor tyrosine kinase (MuSK) cause two distinct phenotypes: fetal akinesia with multiple congenital anomalies (Fetal akinesia deformation sequence [MIM:208150]) and early onset congenital myasthenia (myasthenic syndrome, congenital, 9, associated with acetylcholine receptor deficiency [MIM:616325]). Myasthenia due to MuSK deficiency has variable clinical features, ranging from a milder presentation of isolated late-onset proximal muscle weakness; to a severe presentation of prenatal-onset diffuse weakness, ophthalmoplegia, respiratory failure, and vocal cord paralysis (VCP). Here, we propose to expand the phenotypic spectrum for MuSK deficiency to include isolated VCP with the absence of other classical myasthenic symptoms. We evaluated two brothers who presented in the neonatal period with respiratory failure secondary to isolated VCP. Research-based exome sequencing revealed biallelic likely pathogenic variants in MUSK (MIM:601296). Both children had normal gross motor and fine motor development. One brother had speech delay, likely due to a combination of tracheostomy status and ankyloglossia. This case report suggests that CMS should be on the differential diagnosis for familial recurrence of VCP.

Coffin-Siris syndrome (CSS, MIM 135900), is a well-described, multiple congenital anomaly syndrome characterized by coarse facial features, hypertrichosis, sparse scalp hair, and hypo/aplastic digital nails and phalanges, typically of the 5th digits. Mutations in the BAF (SWI/SNF)-complex subunits (SMARCA4, SMARCE1, SMARCB1, SMARCA2, ARID1B, and ARID1A) have been shown to cause not only CSS, but also related disorders including Nicolaides-Baraitser (MIM 601358) syndrome and ARID1B-intellectual disability syndrome (MIM 614562). At least 200 individuals with CSS have been found to have a mutation in the BAF pathway. However, to date, only three individuals with CSS have been reported to have pathogenic variants in SMARCE1. We report here three additional individuals with clinical features consistent with CSS and alterations in SMARCE1, one of which is novel. The probands all exhibited dysmorphic facial features, moderate developmental and cognitive delay, poor growth, and hypoplastic digital nails/phalanges, including digits not typically affected in the other genes associated with CSS. Two of the three probands had a variety of different organ system anomalies, including cardiac disease, genitourinary abnormalities, feeding difficulties, and vision abnormalities. The 3rd proband has not had further investigative studies. Although an increasing number of individuals are being diagnosed with disorders in the BAF pathway, SMARCE1 is the least common of these genes. This report doubles the number of probands with these mutations, and allows for better phenotypic information of this rare syndrome. © 2016 Wiley Periodicals, Inc.

SOX2 is a transcription factor that is essential for maintenance of pluripotency and has several conserved roles in early embryonic development. Heterozygous loss-of-function variants in SOX2 are identified in approximately 40% of all cases of bilateral anophthalmia/micropthalmia (A/M). Increasingly SOX2 mutation-positive patients without major eye findings, but with a range of other developmental disorders including autism, mild to moderate intellectual disability with or without structural brain changes, esophageal atresia, urogenital anomalies, and endocrinopathy are being reported, suggesting that the clinical phenotype associated with SOX2 loss is much broader than previously appreciated. In this report we describe six new cases, four of which carry novel pathogenic SOX2 variants. Four cases presented with bilateral anophthalmia in addition to extraocular involvement. Another individual presented with only unilateral anophthalmia. One individual did not have any eye findings but presented with a suprasellar teratoma in infancy and was found to have the recurrent c.70del20 mutation in SOX2 (c.70_89del, p.Asn24Argfs*65). This is this first time this tumor type has been reported in the context of a de novo SOX2 mutation. Notably, individuals with hypothalamic hamartomas and slow-growing hypothalamo-pituitary tumors have been reported previously, but it is still unclear how SOX2 loss contributes to their formation.

IF 3.269; International audience; Molecular anomalies in MED13L, leading to haploinsufficiency, have been reported in patients with moderate to severe intellectual disability (ID) and distinct facial features, with or without congenital heart defects. Phenotype of the patients was referred to "MED13L haploinsufficiency syndrome." Missense variants in MED13L were already previously described to cause the MED13L-related syndrome, but only in a limited number of patients. Here we report 36 patients with MED13L molecular anomaly, recruited through an international collaboration between centers of expertise for developmental anomalies. All patients presented with intellectual disability and severe language impairment. Hypotonia, ataxia, and recognizable facial gestalt were frequent findings, but not congenital heart defects. We identified seven de novo missense variations, in addition to protein-truncating variants and intragenic deletions. Missense variants clustered in two mutation hot-spots, i.e., exons 15-17 and 25-31. We found that patients carrying missense mutations had more frequently epilepsy and showed a more severe phenotype. This study ascertains missense variations in MED13L as a cause for MED13L-related intellectual disability and improves the clinical delineation of the condition.

Myelin Regulatory Factor (MYRF) is a transcription factor that has previously been associated with the control of the expression of myelin-related genes. However, it is highly expressed in human tissues and mouse embryonic tissues outside the nervous system such as the stomach, lung, and small intestine. It has not previously been reported as a cause of any Mendelian disease. We report here two males with Scimitar syndrome [MIM 106700], and other features including penoscrotal hypospadias, cryptorchidism, pulmonary hypoplasia, tracheal anomalies, congenital diaphragmatic hernia, cleft spleen, thymic involution, and thyroid fibrosis. Gross neurologic functioning appears to be within normal limits. In both individuals a de novo variant in MYRF was identified using exome sequencing. Neither variant is found in gnomAD. Heterozygous variants in MYRF should be considered in patients with variants of Scimitar syndrome and urogenital anomalies.

The study of embryology and human morphology can provide an enhanced understanding of anatomy in surgical intervention. This chapter will review the critical stages in embryologic development of the human face and how alterations in normal development can produce syndromic and non-syndromic changes in craniofacial, adnexal, and orbital structures.

Hardikar syndrome is a multiple congenital anomaly syndrome first characterized in 1992 by Hardikar et al. to describe two individuals with cholestasis, cleft lip/palate, retinal pigmentation, intestinal abnormalities, and genitourinary anomalies. Between 1992 and 2002, four individuals with Hardikar syndrome were reported in the literature. The fourth individual [Maluf et al. (2002), Transplantation 74:1058-1061; Poley and Proud (2008) Am J Med Genet Part A 146A:2473-2479], who had progressive cholestatic liver disease ultimately requiring liver transplantation, has continued to be followed at our institution. Recently, at the age of 14 years, during an evaluation for refractory hypertension, she was found to have developed coarctation of the aorta that was treated with aortic angioplasty and stenting, dramatically improving her hypertension. Further vascular investigation also revealed a small aneurysm of her carotid artery requiring neurosurgical evaluation and anticoagulant therapy. To our knowledge, these vascular anomalies have not been reported in Hardikar syndrome and the high association of congenital heart disease in the individuals with Hardikar syndrome has not been further addressed. Herein, we discuss this additional clinical information, speculate briefly on possible molecular etiologies, and discuss potential cardiac surveillance recommendations. We hope that broadening the known phenotype of this very rare disorder will further aid clinicians in their management and surveillance for these individuals.

Beare–Stevenson syndrome (BSS) is a rare FGFR2-associated craniosynostosis syndrome with a higher rate of sudden unexplained death than related conditions such as Apert, Pfeiffer, and Crouzon syndromes. BSS presents with craniosynostosis, cutis gyrata, and significant developmental delay in most patients who survive infancy. There have only been 21 reported patients with BSS, which limits prognostication for clinicians and likely does not capture the full extent of the phenotype. Here we report on two additional patients with molecularly confirmed BSS, one each with p.Ser372Tyr and p.Tyr375Cys mutations in FGFR2. Cloverleaf skull was identified prenatally in one patient, with initial concern for Crouzon syndrome. Prenatal 3D ultrasound was performed, but cutis gyrata was only visible on retrospective examination following the clinical diagnosis of BSS after birth. Due to phenotypic overlap with Crouzon syndrome, but worse prognosis, we recommend consideration of prenatal 3D ultrasound and mutation testing for patients with suspected Crouzon to allow for prenatal diagnosis of BSS and to enable appropriate genetic counseling and postnatal care. One of our patients was noted to have a tracheal cartilaginous sleeve, which if present could explain sudden death. Of note, tracheal cartilaginous sleeves have been reported in other FGFR2-related craniosynostosis syndromes, and are associated with 90% risk of death by two years of age without tracheostomy. Tracheal cartilaginous sleeves are often only found incidentally at autopsy as they are difficult to diagnose without direct visualization of the trachea. This association and our experience suggests that BSS patients be evaluated for tracheal cartilaginous sleeve to prevent airway compromise. © 2015 Wiley Periodicals, Inc.

Individuals with Tumor Protein P63 (TP63)-related disorders are known to present with a range of phenotypic features, including ectrodactyly, ectodermal dysplasia, cleft lip/palate, Rapp-Hodgkin, Hay-Wells, and limb-mammary syndromes. We present six individuals from three families, including a set of monozygotic twins, with pathogenic TP63 variants who had novel clinical findings. The twins were discordant for cleft lip and palate, and the type of hand malformations, but concordant for choanal atresia, and bilateral volar nail. Both failed newborn screening for severe combined immunodeficiency (SCID) due to T-cell lymphopenia. The second family included three family members across two generations. Two of these three family members had orofacial clefting, but the remaining child had a laryngeal web and hydrocele with no clefting or hand anomalies, highlighting the variable expressivity in TP63-related disorders. The individual from the third family had unilateral cleft lip and palate, hydronephrosis, and bilateral volar nails. Together, these cases illustrate that: there is significant familial variability, including discordant major but concordant minor anomalies in the first ever reported set of molecularly confirmed monozygotic twins with pathogenic variants in TP63; pathogenic variants in TP63 should be considered in individuals with volar nail, which was previously only strongly associated with 4q34 deletion syndrome; and failed SCID newborn screening due to abnormal immune functioning may be part of the phenotypic spectrum of TP63-related disorders, as it was reported in one prior individual and two of the individuals in our case series.

Because a tracheal cartilaginous sleeve (TCS) confers a significant mortality risk that can be mitigated with appropriate intervention, we sought to describe the prevalence and associated genotypes in a large cohort of children with syndromic craniosynostosis. Chart review of patients with syndromic craniosynostosis across two institutions. In a cohort of 86 patients with syndromic craniosynostosis, 31 required airway evaluation under anesthesia. TCS was found in 19, for an overall prevalence of 22%. FGFR2, TWIST1, and FGFR3 mutations were identified in children with TCS. All five children with a W290C mutation in FGFR2 had TCS, and most previously reported children with W290C had identification of TCS or early death. In contrast, TCS was not associated with other mutations at residue 290. There is an association between TCS and syndromic craniosynostosis, and it appears to be particularly high in individuals with the W290C mutation in FGFR2. Referral to a pediatric otolaryngologist and consideration of operative airway evaluation (i.e., bronchoscopy or rigid endoscopy) in all patients with syndromic craniosynostosis should be considered to evaluate for TCS. Results from genetic testing may help providers weigh the risks and benefits of early airway evaluation and intervention in children with higher-risk genotypes. Genet Med 19 1, 62–68.

A wide range of clinical findings have been associated with mutations in Syntaxin Binding Protein 1 (STXBP1), including multiple forms of epilepsy, nonsyndromic intellectual disability, and movement disorders.STXBP1mutations have recently been associated with mitochondrial pathology, although it remains unclear if this phenotype is a part of the core feature for this gene disorder. We report a 7-year-old boy who presented for diagnostic evaluation of intractable epilepsy, episodic ataxia, resting tremor, and speech regression following a period of apparently normal early development. Mild lactic acidemia was detected on one occasion at the time of an intercurrent illness. Due to the concern for mitochondrial disease, ophthalmologic evaluation was performed that revealed bilateral midperiphery pigmentary mottling. Optical coherence tomography (OCT) testing demonstrated a bilaterally thickened ganglion cell layer in the perifovea. Skeletal muscle biopsy analysis showed no mitochondrial abnormalities or respiratory chain dysfunction. Exome sequencing identified ade novoc.1651C>T (p.R551C) mutation inSTXBP1.Although mitochondrial dysfunction has been reported in some individuals, our proband had only mild lactic acidemia and no skeletal muscle tissue evidence of mitochondrial disease pathology. Thus, mitochondrial dysfunction is not an obligate feature ofSTXBP1disease.

Cerebro-Costo-Mandibular syndrome (CCMS) is a rare autosomal dominant condition comprising branchial arch-derivative malformations with striking rib-gaps. Affected patients often have respiratory difficulties, associated with upper airway obstruction, reduced thoracic capacity, and scoliosis. We describe a series of 12 sporadic and 4 familial patients including 13 infants/children and 3 adults. Severe micrognathia and reduced numbers of ribs with gaps are consistent findings. Cleft palate, feeding difficulties, respiratory distress, tracheostomy requirement, and scoliosis are common. Additional malformations such as horseshoe kidney, hypospadias, and septal heart defect may occur. Microcephaly and significant developmental delay are present in a small minority of patients. Key radiological findings are of a narrow thorax, multiple posterior rib gaps and abnormal costo-transverse articulation. A novel finding in 2 patients is bilateral accessory ossicles arising from the hyoid bone. Recently, specific mutations in SNRPB, which encodes components of the major spliceosome, have been found to cause CCMS. These mutations cluster in an alternatively spliced regulatory exon and result in altered SNRPB expression. DNA was available from 14 patients and SNRPB mutations were identified in 12 (4 previously reported). Eleven had recurrent mutations previously described in patients with CCMS and one had a novel mutation in the alternative exon. These results confirm the specificity of SNRPB mutations in CCMS and provide further evidence for the role of spliceosomal proteins in craniofacial and thoracic development.

Mowat-Wilson syndrome (MWS) is characterized by moderate to severe intellectual disability and distinctive facial features in association with variable structural congenital anomalies/clinical features including congenital heart disease, Hirschsprung disease, hypospadias, agenesis of the corpus callosum, short stature, epilepsy, and microcephaly. Less common clinical features include ocular anomalies, craniosynostosis, mild intellectual disability, and choanal atresia. These cases may be more difficult to diagnose. In this report, we add 28 MWS patients with molecular confirmation of ZEB2 mutation, including seven with an uncommon presenting feature. Among the "unusual" patients, two patients had clinical features of charge syndrome including choanal atresia, coloboma, cardiac defects, genitourinary anomaly (1/2), and severe intellectual disability; two patients had craniosynostosis; and three patients had mild intellectual disability. Sixteen patients have previously-unreported mutations in ZEB2. Genotype-phenotype correlations were suggested in those with mild intellectual disability (two had a novel missense mutation in ZEB2, one with novel splice site mutation). This report increases the number of reported patients with MWS with unusual features, and is the first report of MWS in children previously thought to have CHARGE syndrome. These patients highlight the importance of facial gestalt in the accurate identification of MWS when less common features are present.