Guía clínica para el diagnóstico y seguimiento de la distrofia miotónica tipo 1, DM1 o enfermedad de Steinert / Clinical guide for the diagnosis and follow-up of myotonic dystrophy type 1, MD1 or Steinert's disease

No disponible

Aplasia cutis congenita with dystrophic epidermolysis bullosa: clinical and mutational study.

BACKGROUND: Aplasia cutis congenita (ACC) has been associated with all clinical forms of inherited epidermolysis bullosa (EB), including dominant and recessive dystrophic EB (DDEB and RDEB). To date, only a few patients with DEB specifically combined with ACC have been described and genotyped and almost all cases represent dominant forms of the condition. OBJECTIVES: The aim of this study was to describe new mutations of COL7A1 in patients with DEB and ACC and investigate possible genotype-phenotype correlations. METHODS: Twenty-two patients with DEB and ACC were included among the 123 patients with DEB whose COL7A1 mutations have been identified in the Reference Centre in Nice. RESULTS: Seven patients presented a severe generalized RDEB phenotype (RDEB-sev-gen), while the other 15 suffered from milder phenotypes. We identified 28 mutations in COL7A1, of which nine are novel. Patients with severe phenotypes have mostly mutations leading to premature termination codon (PTC) and/or splice-site or missense mutations. Patients with the milder phenotypes have mostly glycine or arginine substitutions associated or not with other types of mutations. All amino acid substitutions fell within the carboxyl portion of the triple helix domain (THD) of collagen VII, close to the THD interruptions. CONCLUSIONS: Our findings suggest that ACC is a frequent manifestation in patients with DEB irrespective of the severity of the disease, and is due to leg rubbing in utero. In children with a moderate form of DEB with no or moderate skin fragility, a glycine substitution near the THD interruption domain of the collagen VII leading to thermolabile protein could explain this phenomenon.

Cognitive profile in a large French cohort of adults with Prader-Willi syndrome: differences between genotypes.

BACKGROUND: Prader-Willi syndrome (PWS) is a rare genetic disorder characterised by developmental abnormalities leading to somatic and psychological symptoms. These include dysmorphic features, impaired growth and sexual maturation, hyperphagia, intellectual delay, learning disabilities and maladaptive behaviours. PWS is caused by a lack of expression of maternally imprinted genes situated in the 15q11-13 chromosome region. The origin is a 'de novo' deletion in the paternal chromosome in 70% of the cases and a maternal uniparental disomy in 25%. The two main genotypes show differences, notably regarding cognitive and behavioural features, but the mechanisms are not clear. This study assessed cognitive impairment in a cohort of adults with genetically confirmed PWS, analysed their profiles of cognitive strengths and weaknesses, and compared the profiles in terms of genotype. METHODS: Ninety-nine male and female adults participated, all inpatients on a specialised unit for the multidisciplinary care of PWS. The Wechsler Adult Intelligence Scale (WAIS-III) was administered to all patients in identical conditions by the same psychologist. Eighty-five patients were able to cope with the test situation. Their scores were analysed with non-parametric statistical tools. The correlations with sex, age and body mass index were explored. Two genotype groups were compared: deletion (n = 57) and non-deletion (n = 27). RESULTS: The distribution of intelligence quotients in the total cohort was non-normal, with the following values (medians): Full Scale Intelligence Quotient (FSIQ): 52.0 (Q1:46.0; Q3:60.0), Verbal Intellectual Quotient (VIQ): 53.0 (Q1:48; Q3:62) and Performance Intellectual Quotient (PIQ): 52.5 (Q1:48; Q3:61). No correlation was found with sex, age or body mass index. Comparison between groups showed no significant difference in FSIQ or VIQ. PIQ scores were significantly better in the deletion group. The total cohort and the deletion group showed the VIQ = PIQ profile, whereas VIQ > PIQ was observed in the non-deletion group. The subtest scores in the two groups showed significant differences, with the deletion group scoring better in three subtests: object assembly, picture arrangement and digit symbol coding. Some relative strengths and weaknesses concerned the total cohort, but others concerned only one genotype. DISCUSSION: We documented a global impairment in the intellectual abilities of a large sample of French PWS patients. The scores were slightly lower than those reported in most other studies. Our data confirmed the previously published differences in the cognitive profiles of the two main PWS genotypes and offer new evidence to support this hypothesis. These results could guide future neuropsychological studies to determine the cognitive processing in PWS. This knowledge is essential to improve our understanding of gene-brain-behaviour relationships and to open new perspectives on therapeutic and educational programmes.