Genetic Heterogeneity of Hereditary Motor and Sensory Neuropathy Type VI

Abstract

Charcot-Marie-Tooth disease comprises a heterogeneous group of neurologic disorders that share peripheral motor and sensory neuropathy. A classification of these disorders was proposed in 1975, defining seven types of hereditary motor and sensory neuropathy. Clinical features of hereditary motor and sensory neuropathy type VI are muscle weakness and atrophy in leg and hand muscles, leading to progressive disability and loss of vision and progressing to blindness due to optic atrophy. Hereditary motor and sensory neuropathy type VI was first reported in 1879 by Vizioli, who described a kinship in which a father and two sons presented with peroneal muscular atrophy in association with optic atrophy. Since then, at least nine similar cases have been reported: three sporadic cases, two pairs of siblings who were offspring of consanguineous parents, and one pair of siblings who were offspring of unrelated parents, suggesting autosomal recessive inheritance. Vertical transmission has been reported only by Vizioli. We present a father and two offspring (one boy and one girl) with the above-mentioned characteristic features of hereditary motor and sensory neuropathy type VI. Vizioli's kinship and the present family show that hereditary motor and sensory neuropathy type VI is a genetically heterogeneous disorder, with either an autosomal recessive or autosomal dominant pattern of inheritance. (J Child Neurol 1995;10:459-463).