Polydactyly in the multiethnic 'Negev' population at southern Israel.

The objective of this study was to characterize the prevalence, ethnic mix, and associated malformations of polydactyly in a multiethnic population. A retrospective analysis of 189 polydactyly patients was carried out. The incidence of polydactyly was 0.5/1000 live births and was higher in the Bedouin population. Preaxial polydactyly was 10 times more prevalent in the Jewish population and sporadic, and postaxial polydactyly was more prevalent in the consanguineous Bedouin population and associated with other malformations. We conclude that the pathologies in embryogenesis leading to preaxial and postaxial polydactyly vary, with the former occurring sporadically compared with the latter, which predominates in consanguineous families and syndromes.