Mondo Description Odonto-onycho dysplasia-alopecia syndrome is a rare, genetic ectodermal dysplasia syndrome characterized by almost total alopecia with only sparse, thin, brittle, slow-growing scalp hair, fair and sparse eyebrows and eyelashes, absent axillary and pubic hair, fragile and brittle fingernails, thick and brittle toenails (both with a subungual corneal layer), hypodontia, microdontia, widely spaced teeth with hypoplastic enamel, mild palmoplantar keratosis, cafe-au-lait spots and areolae anomalies. There have been no further descriptions in the literature since 1985.