A family of 133 members showing unusual manifestations of vitamin
D-resistant hypophosphatemic osteomalacia was studied. The hypophosphatemic
children did not have rickets or clinical femoral bowing: the
hypophosphatemic young adults had minimum clinically evident femoral
bowing; and the older adults (age forty and older) were progressively
disabled by severe bowing. The disorder appears to be an X-linked dominant,
with almost complete penetrance of the hypophosphatemic trait. The etiology
of this disorder could not be determined.