PROXIMAL FEMORAL FOCAL DEFICIENCY (PFFD) AND FIBULAR A HYPOPLASIA (FA/H) - A MODEL OF A DEVELOPMENTAL FIELD DEFECT/

Proximal femoral focal deficiency (PFFD) and fibular a/hypoplasia (FAM ) are distinct malformations of the lower limbs. Both can occur as iso lated defects or in association with other limb malformations. In fact , fibular defects frequently are present in PFFD, and, conversely, fem oral abnormalities can be found in the presence of a typical FAH pictu re. We report on 5 patients with a variable combination of femoral and fibular defects. In one of them unilateral PFFD was associated with l ateral foot defects, in the absence of fibular abnormalities, and with a phenotype similar to that observed in the femoral hypoplasia/unusua l face syndrome (FH/UFS). Another patient had isolated PFFD on one sid e, with controlateral absence of femur, fibula, and tibia. Another pat ient had a PFFD, fibular hypoplasia, and abnormalities of fibular foot rays, and the last 2 patients, a father and son, had, respectively, b ilateral foot malformations plus fibular and tibial hypoplasia in the father and a PFFD in the son. These observations represent a further d emonstration of the existence of a fibular developmental field, and co ntribute to the definition of its spatial boundaries. The variable inv olvement of elements comprised in the developmental field can be expla ined by multifactorial etiology. (C) 1995 Wiley-Liss, Inc.