Birth prevalence of different congenital limb deficiency types in a revised, population based Hungarian material, 1975-1984.

998 cases affected with limb reduction deficiency were evaluated in Hungary, 1975-1984. Through the check-up of other sources of ascertainments, the Hungarian Congenital Abnormality Registry was found to be 98.4% complete. The proportion of misdiagnoses was 12.6%. In the period encompassed by the study, the birth prevalence of revised cases affected with congenital limb reduction deficiency was 0.55 per 1000 total births. Isolated and multiple cases were separated. The birth prevalence of revised isolated cases was 0.35 per 1000. Six types were separated based on their phenotypic manifestations. As the number of affected limbs, ratio of isolated and multiple cases and sex ratio showed obvious differences, etiological factors should be evaluated separately in these different types of congenital limb deficiencies.