Congenital curved nail of the fourth toe

Five cases of congenital curved nail of the fourth toe are reported. Patients included four males and one female; four cases were bilateral, and one was unilateral. There were no other significant associated anomalies of the extremities, and only the fourth toes were affected. The features of the deformity are a curved nail and hypoplasia of the soft tissue and bone of the distal phalanx of the fourth toe. This anomaly may be transmitted autosomally and is unique in that it may be of mesodermic origin.