Humeroradial Synostosis

In 2 of 3 sons of third-cousin parents, Keutel et al. (1970) described humeroradial synostosis. Frostad (1940) reported recessive inheritance. The parents were from the same small village. The parents in the family reported by Schroder (1932) were likewise consanguineous. Humeroradial synostosis also occurs with the syndrome of multiple synostoses with brachymesophalangy (186500), with Pfeiffer syndrome (101600), and with the SC phocomelia syndrome (269000).

Ramer and Ladda (1989) described sibs with nearly identical humeroradial synostosis. They found records of 9 families with 19 affected individuals with this phenotypic and genetic pattern. Despite the skeletal malformations, functional capability in these patients has been good. Most have been productively employed, and all were able to master their self-care skills. Ramer and Ladda (1989) included among the 9 families that reported by Frankel (1942) in which renal failure accompanied by hematuria and proteinuria developed in young adulthood. Since these patients had patellar subluxation or hypoplasia as well, it is likely that they had the nail-patella syndrome (161200), not the disorder discussed in this entry.

Richieri-Costa et al. (1986) reported the case of an 11-month-old girl whose parents were first cousins and who had plagiobrachycephaly, prominent forehead, broad nasal root, small ears with hypoplastic lobes, an unusual type of multiple synostoses involving humeroradial, carpal, tarsal, and phalangeal joints, and apparent agenesis of the distal phalanges of the postaxial digits. Mental and somatic development was normal. Autosomal recessive inheritance was suggested.