Report of a further family with dominant deafness‐onychodystrophy (DDOD) syndrome

Abstract

Deafness and onychodystrophy is a presumed autosomal dominant condition previously reported in five families. We report on a three-generation family with three affected members with absent finger and toenails, finger-like thumbs, and severe sensorineural deafness. In the hands, the first and fifth digits had absent nails and bulbous swelling of the distal phalanx. The second, third, and fourth digits were relatively spared. In the feet,there were hypoplastic great toenails and absent nails on second to fifth toes. Intelligence was normal. In addition to deafness and onychodystrophy, other features in this family included subtle facial dysmorphism in two individuals, cutis aplasia in one individual, epilepsy in one individual, and sudden infant death in two family members, one of whom had deafness and onychodystrophy and one who did not. A full autopsy of both infants did not reveal a cause. SNP microarray analysis of one family member showed no evidence of copy number change. This family's condition fits within the spectrum of dominant deafness-onychodystrophy syndrome (DDOD) and further characterises this rare condition.