Double little toenails: Report of 4 familial cases.

Double little toenails, or accessory nails of the fifth toe, are a rare and particular deformity distinct from other nail dysplasias. We describe 4 cases of female patients, including a 6-year-old girl, experiencing this bilateral condition after birth. The nail anomaly shows an autosomal-dominant type of transmission that affects only female individuals. The subjects examined were from a family without marriages between blood relatives and without neuroectodermal hereditary diseases. The 4 patients had no bone alterations of the terminal phalanges of the fifth toe or alterations of the joints of the toes or hair. One patient had nail deformity associated with epilepsy; another patient, associated with an infection of an accessory nail.