Phenotype variability of two FAP families with an identical APC germline mutation at codon 1465: a potential modifier effect?

We report the cases of two familial adenomatous polyposis (FAP) families who presented with the same 2 base pair deletion (AG) at codon 1465 of the adenomatous polyposis coli (APC) gene, but showed phenotypic variability. The mutation was revealed by a simple nonradioactive method using a heteroduplex analysis and identified by a sequence analysis. This observation suggests the responsibility of modifier genes in FAP patients' phenotype.

CTG instability in myotonic dystrophy: molecular genetic analysis of families from south-eastern France with characteristics of intergenerational variation in CGT repeat numbers.

We report clinical, genetical and genealogical findings in 149 French families from the Rhône-Alpes area studied over a 5-year period. There was a significant excess of DM females compared to DM males with (CTG) repeat sizes between 1-2 kb. The mean maternal (CTG) repeat size was higher than paternal repeat size.

X-linked dominant Charcot-Marie-Tooth neuropathy (CMTX): new mutations in the connexin32 gene.

X-linked dominant Charcot-Marie-Tooth (CMTX) neuropathy has been mapped to the Xq13 region. Subsequently, several mutations that could account for CMTX have been detected in the coding part of the connexin32 (Cx32) gene, which is located within this region. In order to develop more specific diagnostic tools, we have begun a systematic screening of families with dominant CMTX for mutations in the coding region of the Cx32 gene.

Molecular diagnosis of Charcot-Marie-Tooth 1A disease and hereditary neuropathy with liability to pressure palsies by quantifying CMT1A-REP sequences: consequences of recombinations at variant sites on chromosomes 17p11.2-12.

The most frequent form of Charcot-Marie-Tooth disease (CMT1A; OMIM118.220) is the result of a duplication on chromosome 17 in pll.2-p12.

Genetic heterogeneity in Niemann-Pick C disease: a study using somatic cell hybridization and linkage analysis.

The primary molecular defect underlying Niemann-Pick C disease (NPC) is still unknown. A wide spectrum of clinical and biochemical phenotypes has previously been documented. Indication of genetic heterogeneity has recently been provided for one patient.