Figure 1.

Phenotypes of the right hands of patients carrying L441P and R438L mutations. (A) The L441P mutation is associated with brachydactyly, characterized by a short index finger and bending of finger V (clinodactyly). X-rays show missing middle phalanges in finger II and hypoplasia of the middle phalanges in finger V. (B) The phenotype is very similar to that of BDA2, which is caused by mutations in BMPR1B. (C) The R438L mutation results in SYM1, characterized by bony fusion of the proximal interphalangeal joint of finger V and an abnormal interphalangeal joint in finger IV. (D) The phenotype is very similar to that of SYM1, which is caused by mutations in NOG.