Images of Memorable Cases: Cases 96 & 97 Both of these patients had impaired renal function. 96 & 97. Hereditary osteo-onycho-dysplasia (HOOD) Also known as the nail-patella syndrome and Fong’s disease, this is a genetic disorder of ectodermal and mesodermal tissues characterized by dysplastic nails, deformed elbows, small or absent patellas, and bilateral iliac horns. It is transmitted by an autosomal dominant gene with complete penetrance and variable expressivity, affecting males and females equally. Although the patient on the left is Black, this disorder appears almost exclusively in Caucasians. Renal disease is common and probably constitutes part of the syndrome. Histologically, the kidney shows a variety of cortical and medullary changes.