In this issue of Clinical Chemistry, two groups, Badano et al. (1 ) from Baylor College of Medicine and Latour et al. (2 ) from France, report on PCR of short tandem repeats (STRs) for the diagnosis of Charcot-Marie-Tooth type 1A (CMT1A). CMT1A is caused by the duplication of a 1.4-Mb region on chromosome 17p12 that includes the peripheral myelin protein 22 (PMP22) gene. The increased gene dosa...

Introduction Charcot-Marie-Tooth disease (CMT) is the most common genetic nerve disorder. The most prevalent form, CMT1A, is characterised by demyelinating neuropathy with progressive foot and ankle weakness, contractures and deformity. The wide range of foot/ankle manifestations in CMT1A complicates the assessment, diagnosis and therapy. We aimed to characterise foot and ankle strength, flexib...

The majority of cases of Charcot-Marie-Tooth type 1A (CMT1A) and of hereditary neuropathy with a liability to pressure palsies (HNPP) are the result of heterozygosity for the duplication or deletion of peripheral myelin protein 22 gene (PMP22) on 17p11.2. Southern blots, pulsed-field gel electrophoresis (PFGE), fluorescence in situ hybridization (FISH) and polymorphic marker analysis are curren...

BACKGROUND A 1.5-Mb microduplication containing the gene for peripheral myelin protein 22 (PMP22) on chromosome 17p11.2-12 is responsible for 75% of cases of the demyelinating form of Charcot-Marie-Tooth disease (CMT1A). Methods for molecular diagnosis of CMT1A use Southern blot and/or amplification by PCR of polymorphic poly(AC) repeats (microsatellites) located within the duplicated region, o...

OBJECTIVE Charcot-Marie-Tooth 1A (CMT1A) disease is the most common inherited neuropathy that lacks of therapy and of molecular markers to assess disease severity. Herein, we have pursued the identification of potential biomarkers in plasma samples and skin biopsies that could define the phenotype of CMT1A patients at mild (Mi), moderate (Mo) and severe (Se) stages of disease as assessed by the...

We identified Charcot-Marie-Tooth disease type 1A (CMT1A) in a family with schwannomas in the spinal cord and median nerve. The CMT1A in this family showed an autosomal dominant pattern, like other CMT patients with PMP22 duplication, and the family also indicated a possible genetic predisposition to schwannomas by 'mother-to-son' transmission. CMT1A is mainly caused by duplication of chromosom...

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant neuropathy, most often associated with a deletion of the 17p11.2 region, which is duplicated in 70% of patients with Charcot-Marie-Tooth type 1 (CMT1A). Most de novo CMT1A and HNPP cases have been of paternal origin. A rare case of de novo HNPP of maternal origin was analysed to determine the underlying mec...

Charcot-Marie-Tooth disease type 1A (CMT1A), the most frequent form of CMT, is caused by a 1.5 Mb duplication on the short arm of chromosome 17. Patients with CMT1A typically have slowed nerve conduction velocities (NCVs), reduced compound motor and sensory nerve action potentials (CMAPs and SNAPs), distal weakness, sensory loss and decreased reflexes. In order to understand further the molecul...

Duplication of the gene for the peripheral myelin protein 22 (PMP22) is the most common cause for Charcot-Marie-Tooth neuropathy type 1a (CMT1A) neuropathy. In early stages of the disease PMP22 is overexpressed in nerve biopsies from CMT1A patients. Recent studies with genetically modified Schwann cells have demonstrated that the altered expression of PMP22 modulates cell growth. Thus we hypoth...

The most frequent form of Charcot-Marie-Tooth disease (CMT1A; OMIM118.220) is the result of a duplication on chromosome 17 in p1 l.2-pl2. This region contains PMP22, a gene expressed in peripheral myein. The mutation results from an unequal crossing-over involving repeated sequences, CMT1A-REP, located on both sides of the duplicated region. The reciprocal product of this recombmation is a dele...