Reduction deformities, twinning and mortality in Brazilian Whites and Negroes.

A series of house-to-house surveys in Central Brazil revealed 32 cases of reduction deformities of the limbs (brachydactyly, synbrachydactyly, ectrodactyly, amely, adactyly, achiry, apody, etc.) among 58,761 births (0.54 per thousand, being 0.66 per thousand among Whites and 0.43 per thousand among Mulattoes and Negroes). No sibship was found with two or more equally affected singleton members. One case of concordance among twins is referred. There were no parity, inbreeding, race and sex effects. Both hands and both feet were also equally affected. Precocious mortality and twinning were significantly higher among affected individuals. The presence of cleft lip and palate in one of our index patients may also reflect an etiological relationship. Among the sibs, the total incidence of congenital malformations was similar to that generally accepted for general populations.