Causal study of isolated ulnar-fibular deficiency in Hungary, 1975-1984.

A population-based and validated data set of 114 cases with isolated ulnar-fibular deficiency was evaluated in Hungary, 1975-1984. Ulnar-fibular type had the third most common birth prevalence (0.07 per 1000) among isolated congenital limb deficiency types. This type is relatively rarely associated with nonlimb defects, a single limb is affected in two-thirds of cases, nearly all other cases had femur-fibula-ulna (FFU) dysostosis. Upper and lower limbs, right and left sides, are equally affected, however, there is an obvious male excess (71%). Case-control analysis indicated a lower birth weight due to intrauterine growth retardation, higher birth order, lower socioeconomic status of parents, and a more frequent reported subfertility. The family study identified one familial cluster (one siboccurrence) among 331 first-degree relatives.