Haploinsufficiency of the NOTCH1 Receptor as a Cause of Adams-Oliver Syndrome With Variable Cardiac Anomalies.

BACKGROUND: Adams-Oliver syndrome (AOS) is a rare disorder characterized by congenital limb defects and scalp cutis aplasia. In a proportion of cases, notable cardiac involvement is also apparent. Despite recent advances in the understanding of the genetic basis of AOS, for the majority of affected subjects, the underlying molecular defect remains unresolved. This study aimed to identify novel genetic determinants of AOS. METHODS AND RESULTS: Whole-exome sequencing was performed for 12 probands, each with a clinical diagnosis of AOS. Analyses led to the identification of novel heterozygous truncating NOTCH1 mutations (c.1649dupA and c.6049_6050delTC) in 2 kindreds in which AOS was segregating as an autosomal dominant trait. Screening a cohort of 52 unrelated AOS subjects, we detected 8 additional unique NOTCH1 mutations, including 3 de novo amino acid substitutions, all within the ligand-binding domain. Congenital heart anomalies were noted in 47% (8/17) of NOTCH1-positive probands and affected family members. In leukocyte-derived RNA from subjects harboring NOTCH1 extracellular domain mutations, we observed significant reduction of NOTCH1 expression, suggesting instability and degradation of mutant mRNA transcripts by the cellular machinery. Transient transfection of mutagenized NOTCH1 missense constructs also revealed significant reduction in gene expression. Mutant NOTCH1 expression was associated with downregulation of the Notch target genes HEY1 and HES1, indicating that NOTCH1-related AOS arises through dysregulation of the Notch signaling pathway. CONCLUSIONS: These findings highlight a key role for NOTCH1 across a range of developmental anomalies that include cardiac defects and implicate NOTCH1 haploinsufficiency as a likely molecular mechanism for this group of disorders

Pubertal presentation in seven patients with congenital adrenal hyperplasia due to P450 Oxidoreductase deficiency

Context: P450 oxidoreductase (POR) is a crucial electron donor to all microsomal P450 cytochrome (CYP) enzymes including 17α-hydroxylase (CYP17A1), 21-hydroxylase (CYP21A2) and P450 aromatase. Mutant POR causes congenital adrenal hyperplasia with combined glucocorticoid and sex steroid deficiency. P450 oxidoreductase deficiency (ORD) commonly presents neonatally, with disordered sex development in both sexes, skeletal malformations, and glucocorticoid deficiency. \ud \ud Objective: The aim of the study was to describe the clinical and biochemical characteristics of ORD during puberty. \ud \ud Design: Clinical, biochemical, and genetic assessment of seven ORD patients (five females, two males) presenting during puberty was conducted. \ud \ud Results: Predominant findings in females were incomplete pubertal development (four of five) and large ovarian cysts (five of five) prone to spontaneous rupture, in some only resolving after combined treatment with estrogen/progestin, GnRH superagonists, and glucocorticoids. Pubertal development in the two boys was more mildly affected, with some spontaneous progression. Urinary steroid profiling revealed combined CYP17A1 and CYP21A2 deficiencies indicative of ORD in all patients; all but one failed to mount an appropriate cortisol response to ACTH stimulation indicative of adrenal insufficiency. Diagnosis of ORD was confirmed by direct sequencing, demonstrating disease-causing POR mutations. \ud \ud Conclusion: Delayed and disordered puberty can be the first sign leading to a diagnosis of ORD. Appropriate testosterone production during puberty in affected boys but manifest primary hypogonadism in girls with ORD may indicate that testicular steroidogenesis is less dependent on POR than adrenal and ovarian steroidogenesis. Ovarian cysts in pubertal girls may be driven not only by high gonadotropins but possibly also by impaired CYP51A1-mediated production of meiosis-activating sterols due to mutant POR

PEDIA: prioritization of exome data by image analysis

Purpose Phenotype information is crucial for the interpretation of genomic variants. So far it has only been accessible for bioinformatics workflows after encoding into clinical terms by expert dysmorphologists. Methods Here, we introduce an approach driven by artificial intelligence that uses portrait photographs for the interpretation of clinical exome data. We measured the value added by computer-assisted image analysis to the diagnostic yield on a cohort consisting of 679 individuals with 105 different monogenic disorders. For each case in the cohort we compiled frontal photos, clinical features, and the disease-causing variants, and simulated multiple exomes of different ethnic backgrounds. Results The additional use of similarity scores from computer-assisted analysis of frontal photos improved the top 1 accuracy rate by more than 20–89% and the top 10 accuracy rate by more than 5–99% for the disease-causing gene. Conclusion Image analysis by deep-learning algorithms can be used to quantify the phenotypic similarity (PP4 criterion of the American College of Medical Genetics and Genomics guidelines) and to advance the performance of bioinformatics pipelines for exome analysis

Phenotypic spectrum and transcriptomic profile associated with germline variants in TRAF7

PURPOSE: Somatic variants in tumor necrosis factor receptor-associated factor 7 (TRAF7) cause meningioma, while germline variants have recently been identified in seven patients with developmental delay and cardiac, facial, and digital anomalies. We aimed to define the clinical and mutational spectrum associated with TRAF7 germline variants in a large series of patients, and to determine the molecular effects of the variants through transcriptomic analysis of patient fibroblasts. METHODS: We performed exome, targeted capture, and Sanger sequencing of patients with undiagnosed developmental disorders, in multiple independent diagnostic or research centers. Phenotypic and mutational comparisons were facilitated through data exchange platforms. Whole-transcriptome sequencing was performed on RNA from patient- and control-derived fibroblasts. RESULTS: We identified heterozygous missense variants in TRAF7 as the cause of a developmental delay-malformation syndrome in 45 patients. Major features include a recognizable facial gestalt (characterized in particular by blepharophimosis), short neck, pectus carinatum, digital deviations, and patent ductus arteriosus. Almost all variants occur in the WD40 repeats and most are recurrent. Several differentially expressed genes were identified in patient fibroblasts. CONCLUSION: We provide the first large-scale analysis of the clinical and mutational spectrum associated with the TRAF7 developmental syndrome, and we shed light on its molecular etiology through transcriptome studies

Am J Med Genet A

Focal facial dermal dysplasia (FFDD) (OMIM 227260) is a rare ectodermal disorder characterized by congenital bitemporal scar-like depressions resembling forceps marks and variable additional facial manifestations. No gene defects or gene loci for FFDD are known to date. We report on a large multi-generational German family with typical characteristics of FFDD and provide a detailed clinical description of four affected individuals. They had large bitemporal discolored dermal depressions, sparse lateral eyebrows, abnormal eyelashes, and dysplastic and low-set ears. Three of the four affected individuals had congenital horizontal nystagmus, which had hitherto only been reported in a single patient with FFDD. In contrast to previous assumptions about an autosomal recessive etiology of this disorder, this family provides further evidence that FFDD is inherited in an autosomal dominant mode. Although this family is not large enough to yield significant results in linkage analysis, it may, in combination with other families, contribute to the identification of a gene locus for this intriguing ectodermal disorder

Am J Med Genet A

Czech dysplasia (OMIM 609162) is a recently delineated COL2A1 disorder characterized by early-onset progressive pseudorheumatoid arthritis, platyspondyly, short third and fourth metatarsals, normal height, and the absence of ophthalmological problems or cleft palate. Czech dysplasia is caused by a specific missense mutation (R275C, c.823C > T) in the triple helical domain of the COL2A1 gene. We report on a large family with 11 patients with typical Czech dysplasia and sensorineural hearing loss. Hearing loss has hitherto not been considered as a major manifestation of Czech dysplasia. Mutation analysis documented the COL2A1 c.823C > T (R275C) mutation in all affected individuals. Thus, Czech dysplasia is possibly caused exclusively by the R275C mutation, which is a unique situation among the COL2A1 disorders. The family provides further evidence for the remarkably uniform manifestation of the clinical and radiological abnormalities and adds hearing loss to the list of major anomalies of Czech dysplasia

Microdeletions of chromosome 7p21, including TWIST1, associated with significant microcephaly, facial dysmorphism, and short stature

Saethre-Chotzen syndrome due to TWIST1 mutations is characterized by coronal synostosis, facial dysmorphism and additional variable anomalies. Small deletions comprising the whole TWIST1 account for a small proportion of patients with Saethre-Chotzen syndrome. Here we describe 3 patients with facial dysmorphism, marked microcephaly, short stature (2/3 patients), and overlapping 7p21 microdeletions. Molecular karyotyping identified small deletions of chromosome 7p21 including TWIST1 with a size of 526 kb, 9.2 Mb, and 11.7 Mb, respectively. The clinical manifestations of these patients do not resemble the typical phenotype of Saethre-Chotzen syndrome. In the two patients with larger microdeletions, severe mental retardation and significant short stature are present. Facial dysmorphism of patient 3 includes also signs of blepharophimosis-ptosis-epicanthus inversus syndrome

Two Adult Patients with Ellis-van Creveld Syndrome Extending the Clinical Spectrum

Ellis-van Creveld (EvC) syndrome is a rare autosomal recessive malformation syndrome with the main features cardiac defects, postaxial hexadactyly, mesomelic shortening of the limbs, short ribs, dysplastic nails and teeth, oral frenula and various other abnormalities while mental function is normal. We describe 2 adult EvC patients with the cardinal skeletal features of mesomelic short stature and severe, progressive genu valgum deformity, resulting from loss of function mutations in the EVC genes. While the genu valgum was the predominating and disabling feature in patient 1, patient 2 showed acroosteolyses in the distal phalanges and a symmetrical synostosis of metacarpals in his hands. Moreover, patient 2 developed synostoses in the additional fingers in adolescence which had not been present at the age of 12 years, suggesting a further progression of skeletal disease. Joint fusion of phalanges so far has not been reported in EvC syndrome. Our data further expand the phenotypic spectrum of EvC related skeletal malformations and contribute important new information on the clinical course of EvC syndrome with increasing age