The phenotypic manifestations of autosomal recessive axonalCharcot–Marie–Tooth due to a mutation in Lamin A/C gene

Abstract

Charcot–Marie–Tooth disease constitutes a genetically heterogeneous group of hereditary motor and sensory peripheral neuropathies. The axonal type of Charcot–Marie–Tooth is designated type 2. Six loci for autosomal dominant and three for recessive Charcot–Marie–Tooth type 2 have been reported so far. In this study we report the phenotype of autosomal recessive axonal Charcot–Marie–Tooth type 2 due to a recently-described mutation (c.892C>T–p.R298C) in a gene encoding Lamin A/C nuclear envelope proteins and the first gene in which a mutation leads to autosomal recessive Charcot–Marie–Tooth type 2. We have explored eight patients from four Algerian families. The onset is usually in the second decade and the course is rapid, involving upper limbs and proximal muscles, leading to a severe condition in less than 4 years. Many different mutations in Lamin A/C have been identified as causing variable phenotypes, such as limb girdle muscular dystrophy type 1B, autosomal dominant and recessive Emery–Dreyfuss muscular dystrophy, dilated cardiomyopathy with atrioventricular conduction defect, and Dunnigan-type familial partial lipodystrophy should prompt us to fully investigate the skeletal and cardiac muscles in patients affected with autosomal recessive Charcot–Marie–Tooth type 2 carrying a mutation in LMNA.