Humeroradial Synostosis

Hunter et al. (1976) concluded that humeroradial synostosis occurs as either a dominant or a recessive (see 236400) malformation and also as part of the SC phocomelia syndrome (269000). Families with dominant inheritance were reported by Romanus (1933), Fuhrmann et al. (1966) and Mouchet and St. Pierre (1931).

Lenz and Rehmann (1976) reported a remarkable kindred in which 12 of the 27 persons in 4 generations had bilateral humeroradial synostosis and the other 15 had ventral luxation of the radius. In addition, various degrees of malformations and aplasia of the carpal, tarsal and interphalangeal joints as well as shortening of the proximal phalanx of the thumbs were observed. The authors considered this to be a distinct syndrome.

Humeral 'bifurcation' due to humeroradial synostosis, and amelia (see 601360) are both very rare limb anomalies. Marles et al. (2003) described a Canadian Aboriginal boy with both of these limb deficiencies. The family history was unremarkable, but the proband had been exposed prenatally to cocaine at the time of limb development. His exposure was thought to be the likely cause.