Mild recurrent neuropathy in CMT1B with a novel nonsense mutation in the extracellular domain of the MPZ gene
- aService de Neurologie, Hôpital du Haut Levêque, USN, Avenue de Magellan, CHU Bordeaux, 33604 Pessac, France, bUnité de Neurogénétique Moléculaire, Hospices civils de Lyon, 69005 Lyon, France, cLaboratoire de Neuropathologie, Université de Bordeaux II, 33076 Bordeaux, France
- Dr A Laguenyalain.lagueny{at}chu-bordeaux.fr
- Received 19 May 2000
- Revised 25 July 2000
- Accepted 28 September 2000
Abstract
Clinical, electrophysiological, and neuropathological features are reported associated with a novel heterozygote point mutation in the extracellular domain of the MPZ gene, where a transversion at codon 71 in exon 3 leads to a codon stop: Glu71stop (ie GAA→TAA). A 36 year old woman developed a mild recurrent neuropathy after intensive manual work. The motor nerve conduction velocities were slow without conduction blocks and the nerve biopsy showed signs of demyelination-remyelination, axonal loss, and regular uncompacted myelin lamellae. She inherited the mutation from her father who displayed the same mutation with a normal phenotype. This nonsense mutation may cause a dosage difference of normal P0, and is probably underrepresented in the current mutation data bases. This report further extends the phenotype of MPZ mutations and also emphasises that mild phenotype of CMT1B may be more frequent than has been appreciated.
