0000000000205828
AUTHOR
Daniel Amram
Phenotypic spectrum and genomics of undiagnosed arthrogryposis multiplex congenital
BackgroundArthrogryposis multiplex congenita (AMC) is characterised by congenital joint contractures in two or more body areas. AMC exhibits wide phenotypic and genetic heterogeneity. Our goals were to improve the genetic diagnosis rates of AMC, to evaluate the added value of whole exome sequencing (WES) compared with targeted exome sequencing (TES) and to identify new genes in 315 unrelated undiagnosed AMC families.MethodsSeveral genomic approaches were used including genetic mapping of disease loci in multiplex or consanguineous families, TES then WES. Sanger sequencing was performed to identify or validate variants.ResultsWe achieved disease gene identification in 52.7% of AMC index pati…
Application of whole-exome sequencing to unravel the molecular basis of undiagnosed syndromic congenital neutropenia with intellectual disability
International audience; Neutropenia can be qualified as congenital when of neonatal onset or when associated with extra-hematopoietic manifestations. Overall, 30% of patients with congenital neutropenia (CN) remain without a molecular diagnosis after a multidisciplinary consultation and tedious diagnostic strategy. In the rare situations when neutropenia is identified and associated with intellectual disability (ID), there are few diagnostic hypotheses to test. This retrospective multicenter study reports on a clinically heterogeneous cohort of 10 unrelated patients with CN associated with ID and no molecular diagnosis prior to whole-exome sequencing (WES). WES provided a diagnostic yield o…
Molecular diagnosis of PIK3CA-related overgrowth spectrum (PROS) in 162 patients and recommendations for genetic testing.
Postzygotic activating mutations of PIK3CA cause a wide range of mosaic disorders collectively referred to as PIK3CA-related overgrowth spectrum (PROS). We describe the diagnostic yield and characteristics of PIK3CA sequencing in PROS. We performed ultradeep next-generation sequencing (NGS) of PIK3CA in various tissues from 162 patients referred to our clinical laboratory and assessed diagnostic yield by phenotype and tissue tested. We identified disease-causing mutations in 66.7% (108/162) of patients, with mutant allele levels as low as 1%. The diagnostic rate was higher (74%) in syndromic than in isolated cases (35.5%; P = 9.03 × 10−5). We identified 40 different mutations and found stro…