In a family with genetically dominant joint aplasia, 12 of the 27 involved members in four generations had bilateral humeroradial synostoses; the rest, 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 thumb were observed. All other similar cases described in the available literature differ significantly from those described here.