Bilateral aplasia of the tibia, polydactyly and absent thumb in father and daughter.

The syndrome of bilateral aplasia of the tibia, polydactyly with or without syndactyly, and absence of the thumbs, was first reported in 1915 by Werner in a twenty-year-old woman in her sixth month of pregnancy who requested an abortion because the pregnancy was causing her difficulties. The patient had no thumbs and six fingers, each with a metacarpal bone. There were eight toes on the left foot and seven on the right. The lower limbs were very short and there was aplasia of the tibiae; movement was greatly reduced at the “knee-ankle” joint. She delivered a normal baby at term. There were no affected relatives. In 1918 Davidson reported the second case, in a two-year-old baby. The patient had no thumbs and five well formed fingers of equal length, each with a metacarpal bone. He was able to use both hands well. Each foot had eight formed toes. The lower limbs were very short and there was a complete absence of the tibiae ; the fibulae were present but articulation was faulty at both ends. The lower legs were unstable and the child walked with difficulty by inverting his feet and bearing weight on the outer sides of the legs. There were no affected relatives. Fifty years later Reber (1968) described the first familial case. His propositus was an eight-year-old boy with bilateral aplasia of the tibiae, polydactyly of feet, and ten fingers with three phalanges each. The father also had ten fingers but no thumbs. Two fourth degree relatives had ectrodactyly, but were not themselves related. A “secondary case” with heptadactyly was only an eighth degree relative of the proband. These defects in distant relatives are probably unrelated to those of the proband and his father. A second familial case was reported by Eaton and McKusick (1969), who described a man with absent thumbs and pre-axial polydactyly of the feet, but with normal tibiae. His two daughters and one granddaughter showed polydactyly of the toes, hypoplastic tibiae, absent patellae, absent thumbs and polydactyly of the fingers. The findings in the above two families strongly suggest the existence ofan autosomal dominant gene with variable expressivity, causing absent thumbs and manual polydactyly, with or without varying degrees of tibial hypoplasia and pedal polydactyly. This paper reports a case of virtually identical expression of the syndrome in father and daughter.