Waardenburg syndrome and Hirschsprung disease: Evidence for pleiotropic effects of a single dominant gene

Abstract

Segregation and linkage analysis was performed on published data on 5 families segregating for Waardenburg syndrome (WS) and Hirschsprung disease (HRSD). Two of these families demonstrated parental consanguinity. On the basis of these families, autosomal recessive inheritance of the combination WS‐HRSD has been postulated. However, a single dominant gene with pleiotropic effects leading to WS and HRSD, with a more severe phenotype in homozygotes, is more plausible. A model of gene action incorporating stochastic effects is compatible with these observations.