0000000000946224
AUTHOR
Eva Pipiras
Molecular characterization of 39 de novo sSMC: contribution to prognosis and genetic counselling, a prospective study.
Small supernumerary marker chromosomes (sSMCs) are structurally abnormal chromosomes that cannot be characterized by karyotype. In many prenatal cases of de novo sSMC, the outcome of pregnancy is difficult to predict because the euchromatin content is unclear. This study aimed to determine the presence or absence of euchromatin material of 39 de novo prenatally ascertained sSMC by array-comparative genomic hybridization (array-CGH) or single nucleotide polymorphism (SNP) array. Cases were prospectively ascertained from the study of 65,000 prenatal samples [0.060%; 95% confidence interval (CI), 0.042-0.082]. Array-CGH showed that 22 markers were derived from non-acrocentric markers (56.4%) a…
WWOX-related encephalopathies: delineation of the phenotypical spectrum and emerging genotype-phenotype correlation
International audience; BACKGROUND:Homozygous mutations in WWOX were reported in eight individuals of two families with autosomal recessive spinocerebellar ataxia type 12 and in two siblings with infantile epileptic encephalopathy (IEE), including one who deceased prior to DNA sampling.METHODS:By combining array comparative genomic hybridisation, targeted Sanger sequencing and next generation sequencing, we identified five further patients from four families with IEE due to biallelic alterations of WWOX.RESULTS:We identified eight deleterious WWOX alleles consisting in four deletions, a four base-pair frameshifting deletion, one missense and two nonsense mutations. Genotype-phenotype correl…
Incomplete penetrance and phenotypic variability of 6q16 deletions including SIM1.
International audience; 6q16 deletions have been described in patients with a Prader-Willi-like (PWS-like) phenotype. Recent studies have shown that certain rare single-minded 1 (SIM1) loss-of-function variants were associated with a high intra-familial risk for obesity with or without features of PWS-like syndrome. Although SIM1 seems to have a key role in the phenotype of patients carrying 6q16 deletions, some data support a contribution of other genes, such as GRIK2, to explain associated behavioural problems. We describe 15 new patients in whom de novo 6q16 deletions were characterised by comparative genomic hybridisation or single-nucleotide polymorphism (SNP) array analysis, including…