Copy number variation upstream of PMP22 in Charcot-Marie-Tooth disease.

In several individuals with a Charcot-Marie-Tooth (CMT) phenotype, we found a copy number variation (CNV) on chromosome 17p12 in the direct vicinity of the peripheral myelin protein 22 (PMP22) gene. The exact borders and size of this CNV were determined by Southern blot analysis, MLPA, vectorette PCR, and microarray hybridization analyses. All patients from six apparently unrelated families carried an identical 186-kb duplication different from the commonly reported 1.

Early onset neuropathy in a compound form of Charcot-Marie-Tooth disease.

A 2-year-old boy presented with early-onset Charcot-Marie-Tooth disease (CMT). His parents had not been diagnosed previously with CMT, but on careful examination they showed clinical signs of CMT and reduced nerve conduction velocities. Genetic analysis identified the boy as a heterozygote for both a peripheral myelin protein 22 (PMP22) duplication and a mutation in the lipopolysaccharide-induced-tumour-necrosis-factor-alpha-factor (LITAF) gene, whereas each parent only had one mutated CMT gene.

Clinical comparison between AVED patients with 744 del A mutation and Friedreich ataxia with GAA expansion in 15 Moroccan families.

Fifteen Moroccan families with a phenotype resembling Friedreich Ataxia (FA) were studied. Seven families (13 patients) had the 744 del A mutation in the alpha-tocopherol transfer protein (alpha-TTP) gene, characteristic of ataxia with vitamin E deficiency (AVED). The other eight families (16 patients) had GAA expansions in the first intron of the frataxin gene.