0000000000427745
AUTHOR
Hartmut Engels
Tetrasomy 18p de novo: Identification by FISH with conventional and microdissection probes and analysis of parental origin and formation by short sequence repeat typing
We report a de novo supernumerary isochromosome 18p in a child with tetrasomy 18p, analyzed by a straightforward combination of cytogenetic and molecular cytogenetic methods. The diagnostic procedure consisted of standard banding techniques and fluorescence in situ hybridization (FISH) with centromere and library DNA probes for chromosome 18, and 18p-specific FISH probes prepared by chromosome microdissection and in vitro amplification. The maternal origin as well as the most probable cell stages of formation of the supernumerary isochromosome were determined by typing of short sequence repeats (SSRs). The pattern of allelic distribution suggests a nondisjunction during meiosis followed by …
Homozygous mutations incaveolin-3cause a severe form of rippling muscle disease
Heterozygous missense mutations in the caveolin-3 gene (CAV3) cause different muscle disorders. Most patients with CAV3 alterations present with rippling muscle disease (RMD) characterized by signs of increased muscle irritability without muscle weakness. In some patients, CAV3 mutations underlie the progressive limb-girdle muscular dystrophy type 1C (LGMD1C). Here, we report two unrelated patients with novel homozygous mutations (L86P and A92T) in CAV3. Both presented with a more severe clinical phenotype than usually seen in RMD. Immunohistochemical and immunoblot analyses of muscle biopsies showed a strong reduction of caveolin-3 in both homozygous RMD patients similar to the findings in…
Bainbridge-Ropers syndrome caused by loss-of-function variants in ASXL3: a recognizable condition
International audience; Truncating ASXL3 mutations were first identified in 2013 by Bainbridge et al. as a cause of syndromic intellectual disability in four children with similar phenotypes using whole-exome sequencing. The clinical features - postulated by Bainbridge et al. to be overlapping with Bohring-Opitz syndrome - were developmental delay, severe feeding difficulties, failure to thrive and neurological abnormalities. This condition was included in OMIM as 'Bainbridge-Ropers syndrome' (BRPS, #615485). To date, a total of nine individuals with BRPS have been published in the literature in four reports (Bainbridge et al., Dinwiddie et al, Srivastava et al. and Hori et al.). In this re…
Familial Sotos syndrome caused by a novel missense mutation, C2175S, in NSD1 and associated with normal intelligence, insulin dependent diabetes, bronchial asthma, and lipedema
We report a familial Sotos syndrome in two children, boy and girl, aged 17 and 8 years, and in their 44 year old mother, who displayed normal intelligence at adult age, but suffered from insulin dependent diabetes mellitus, bronchial asthma, and severe lipedema. The underlying missense mutation, C2175S, occurred in a conserved segment of the NSD1 gene. Our findings confirm that familial cases of SS are more likely to carry missense mutations. This case report may prove useful to avoid underestimation of the recurrence rate of SS, and to demonstrate that the developmental delay may normalize, enabling an independent life and having an own family.
Genome-wide analysis for micro-aberrations in familial exstrophy of the bladder using array-based comparative genomic hybridization
OBJECTIVE: Exstrophy of the bladder (EB) is part of the bladder-exstrophy-epispadias complex (BEEC). Because familial occurrence of BEEC is rare, exogenous factors are thought to play a major role in the etiology of most BEEC cases. We aimed to investigate a possible genetic basis of BEEC in a consanguineous kindred of Moroccan origin with three members showing the same phenotypic expression of BEEC. PATIENTS AND METHODS: The three affected males (two cousins and their maternal uncle) all presenting with nonsyndromic classic EB, were born in Morocco or The Netherlands. One Moroccan patient had an open bladder surface for 22 years due to late surgical reconstruction, avoided upright posture …
New insights into the clinical and molecular spectrum of the novel CYFIP2-related neurodevelopmental disorder and impairment of the WRC-mediated actin dynamics.
International audience; Purpose: A few de novo missense variants in the cytoplasmic FMRP-interacting protein 2 (CYFIP2) gene have recently been described as a novel cause of severe intellectual disability, seizures, and hypotonia in 18 individuals, with p.Arg87 substitutions in the majority.Methods: We assembled data from 19 newly identified and all 18 previously published individuals with CYFIP2 variants. By structural modeling and investigation of WAVE-regulatory complex (WRC)-mediated actin polymerization in six patient fibroblast lines we assessed the impact of CYFIP2 variants on the WRC.Results: Sixteen of 19 individuals harbor two previously described and 11 novel (likely) disease-ass…