Aplasia Of Extensor Muscles Of Fingers, Unilateral, With Generalized Polyneuropathy

Among the 9 children of parents related as first cousins once removed, Hamanishi et al. (1986) found 3 (a female and 2 males) with a curious combination of manifestations: congenital unilateral flexion deformities of the thumb and some fingers, and 'polyneuropathic electrophysiologic findings' in all 4 limbs. The sibs were young adults at the time of report. At operation, the extensor muscles and their tendons were absent or hypoplastic. The hand without flexion deformities showed hypesthesia and hypohidrosis on the radial side. It appears that the polyneuropathy was asymptomatic. It was noted in the case of the oldest that 'sensory disturbance was first noticed in the right hand when she was 11 years old.'