St. Helena familial genu valgum.

A kindred on the mid-Atlantic island of St. Helena has severe "knock knees" and variable lesser malalignment at the elbows and wrists. The disorder is the consequence of hypoplasia of the corresponding bony condyles, with subsequent progressive degenerative osteoarthrophy. Inheritance is autosomal dominant and the condition seems to be a private syndrome which has arisen on the island by recent mutation. In view of the geographical localisation of the disorder and the anatomical distribution of the abnormalities, we propose the title "St. Helena Familial Genu Valgum".