New type of synpolydactyly of hands and feet in two unrelated males.

An 18-year-old Japanese boy and a 10-year-old Chinese boy both had nearly complete cutaneous syndactyly of the fingers and toes, six diphalangeal fingers on each hand, six toes on each foot (except the right foot of patient 2), and short, deformed, and on occasion partially fused metacarpals and metatarsals. Neither had other malformations and were of normal intelligence. The accessory toes in patient 1 were mesoaxial, each situated between the hallux and the third toe, whereas those in patient 2 were postaxial. In view of these findings, the disorder in 2 individuals is likely to represent a hitherto undescribed type of nonsyndromic synpolydactyly.