[A family of hereditary motor and sensory neuropathy with spastic paraplegia (HMSN type V)].

Three siblings with hereditary motor and sensory neuropathy with spastic paraplegia (HMN V) were described. Their grandfather was suspected to have the similar symptoms. Their parents were normal and not consanguineous. The first case was a 54-year-old woman. She has suffered from difficulty in walking since the age of 10 years. Distal muscular weakness and wasting began at 20 years old. She was admitted to our hospital for investigation in 1988. Results of examination of the brain, cranial nerve, and cerebellar function were normal. The deep reflexes were hyperactive in the arm and knee, while absent at the ankle. Babinski's sign was definitely positive. Muscular weakness and wasting were noted in intrinsic hand muscles and in those below her knees. There were pes cavus and hammer toes, and the gait was spastic. Mild sensory disturbance was noted in distal limbs. The conduction velocity of motor nerve fibers of her limbs was below normal and that of sensory nerve fibers normal. Muscle biopsy of biceps brachii revealed neurogenic changes. Sural nerve biopsy showed decreased number of myelinated fibers of large diameter and formation of small oinion-bulb. The second and third cases were her brothers and proven to have the similar condition, but their onset of illness were earlier and their affections were more severe. A few cases of HMSN V with nerve biopsy findings have so far been reported and the family presented here is the first report in Japan.