Abstract
Proximal femoral focal deficiency (PFFD) is a rare skeletal dysplasia, characterized
by hypoplasia of the subtrochanteric femur with variable degrees of shortening of
the femoral shaft. There are numerous gene e.g. TBX4, FGF, FGFR, TP63 and HOX responsible
for limb formation, type and its shape. Normal limb development is three dimensional;
proximodistal axis regulated by AER; anteroposterior axis (preaxial/postaxial) governed
by SHH with ZPA and dorsoventral axis controlled by LMX1B. Primigravida with diamniotic
dichorionic twins in first trimester was found to have absent right femur, fibula
and left femural bone with hypoplastic right foot in one foetus. Right tibia, both
left tibia and fibula and left foot were visualized normally. Bilateral humerus, radius
and ulna along with digits were visualized with no evidence of oligodactyly. Twin
II had no major limb reduction defect. Both nasal bones, hard palate were visualized;
nuchal translucency was within normal range for the foetus of 13 weeks 3 days of duration;
suggestive of bilateral PFFD; Aitken type 4 in Twin I. We are the first to describe
bilateral PFFD in the first trimester of pregnancy. Nuchal scan provides a window
of opportunity to the foetal medicine specialists to screen the foetus for major congenital
anomalies and to proceed with further investigation or with selective reduction as
in this case so as to optimize the pregnancy outcome. Identification of PFFD at 13
weeks with foetal reduction helped in minimizing the risk to the surviving foetus.
Keywords
Femoral - Deficiency - Genes - DADC - Skeletal - PFFD - First - Trimester - Aitken
