Congenital pocomelia in monozygotic twins.

Phocomelia is the congenital absence of legs and arms, resulting In the hands and feet being in close proximity to the trunk. Occasionally deformed intermediate segments may be demonstrated radiologically (Carey, 1919), though the limb girdles and digital elements may appear normal. In the past decade interest has been taken in abnormalities showing phocomelia as a result of thalidomide taken by the mother during pregnancy. It has been shown (Lenz and Knapp, 1962) that a critical period of sensitivity, 34 to 50 days after the last menstrual cycle or 20 to 36 days' ovulation age, exists in the human in those cases having thalidomide deformities. These results have recently been reproduced in mammals, including primates (Hendricks et al., 1966). Similar defects are known to have existed many years before the use of this drug. Two paintings, one entitled Handschriften depicting the armless town clerk of Nuremberg at the end of the sixteenth century (Oertel, 1962), and the other by Goya