Molecular genetics and clinical aspects of inherited disorders of nerve and muscle.

Rapid progress has been made in elucidating the molecular genetic basis of several neuromuscular disorders in the past year. Candidate genes have been identified or analysed in hereditary motor and sensory neuropathy (HMSN) type I, X-linked bulbospinal neuronopathy and non-dystrophic myotonic disorders, and further mutations causing amyloidosis have been identified. A familial amyotrophic lateral sclerosis (ALS) locus maps to chromosome 21 in some families, and the chronic childhood spinal muscular atrophy (SMA), facioscapulohumeral muscular dystrophy (FSHD) and malignant hyperthermia loci have been localized more precisely.