The genetics of and associated clinical findings in humero-radial synostosis.

This paper compares the manifestations of sporadic, dominantly inherited and recessively inherited humero-radial synostosis with the aim of determining ways of separating these forms on clinical grounds. The genetic forms are characterized by bilateral involvement and by lack of the distal ulnar malformations and the absence of digits that are common in the sporadic cases. The majority of patients with the dominantly inherited form have a characteristic pattern of anomalies, including brachymesophalangy, and the recessive cases have a high frequency of malformations in addition to those of the limbs. Consanguinity is frequent in the families of recessive cases. Four additional patients are presented; two of them illustrate many of the features of the phocomelic syndrome reported by Herrmann et al. (1969). A possible teratogenic cause of these cases is discussed.