Denouement and Discussion
Hereditary Osteo-Onycho Dysplasia
(HOOD, Fong's Syndrome, Touraine Syndrome, Nail-Patella Syndrome)CONTRIBUTED BY FORREST G. MOYER, MD, ALLENTOWN, PA
There is absence, hypoplasia, or dislocation of the patellas, deformity or absence of the nails, bony projections (iliac horns) arising from the central area of the external iliac fossa, and elbow deformities.
Transmitted as a mendelian dominant trait which is probably mediated by a single mutant autosomal gene with variable expressivity.
There is an equal distribution, although some reports have shown a higher incidence in females.
The nail involvement may range from a slight longitudinal ridging to complete absence of the nail. Most commonly involved are the thumb and great toe, and there is decreased nail involvement as one goes from the thumb to the little finger. There may be a longitudinal