Hereditary motor and sensory neuropathy associated with cerebellar atrophy (HMSNCA): a new disease.

Seven patients with hereditary motor and sensory neuropathy associated with cerebellar atrophy (HMSNCA) are presented. This is the first comprehensive evaluation of what is a unique disorder, half way between the cerebellar atrophies and the hereditary motor and sensory neuropathies. In addition to cerebellar ataxia and peripheral neuropathy, the most frequent features in HMSNCA were nystagmus, dysarthria, mental impairment and tremor. Pyramidal signs or autonomic nerve dysfunction was never revealed. Scoliosis or kyphoscoliosis was not noted. Progression of the disorder was very slow, most of the patients being ambulatory more than 10 years after the onset. Most of the patients had hypoalbuminemia. Half-life periods of serum albumin were normal and decreased synthesis of albumin in the liver was suspected. An autosomal recessive inheritance was strongly suggested, because of healthy consanguineous parents and affected siblings in these families. The segregation ratio was 0.32 +/- 0.10 and was close to the expected ratio of 0.25 in an autosomal recessive inheritance.