Prevalence of hereditary motor and sensory neuropathy in Cantabria.

One hundred and forty-four patients with hereditary motor and sensory neuropathy (HMSN) were selected from within a defined area (Cantabria) in Northern Spain, from 1974 to 1984. The series comprises 49 index cases and 95 affected relatives. The prevalence ratio was 28.2 cases per 100,000. The results of the study indicate that the majority of the cases were hereditary as a dominant trait. The prevalence for the Type I HMSN cases did not differ from that of Type II cases. Previous population-surveys of these disorders are compared.