Hereditary sensory neuropathy: biopsy study of an autosomal dominant variety.

We studied sural nerve biopsies from a family in which three members in two generations (father, son, and daughter) had a dominantly inherited neuropathy (HSAN-I). There was marked loss of myelinated fibers, especially those of large diameter, and there was comparable loss of unmyelinated fibers. These quantitative findings differed from another reported case that provided basis for the classification of dominant and recessively inherited sensory neuropathies. Few patients have been studied, so ultrastructural and morphometric data have limited value in classification of these disorders, for which there is still no known biochemical marker.