Mondo Description Ectodermal dysplasia-syndactyly syndrome is a rare, genetic ectodermal dysplasia syndrome characterized by sparse to absent scalp hair, eyebrows, and eyelashes (with pili torti when present), widely spaced, conical-shaped teeth with peg-shaped, conical crowns and enamel hypoplasia and palmoplantar hyperkeratosis, associated with partial cutaneous syndactyly in hands and feet.