Clinical expression of co-inherited Dubin-Johnson and thalassaemic heterozygous states.

Dubin-Johnson syndrome is a worldwide prevalent familial conjugated hyperbilirubinaemia. The identification of multidrug resistance-associated protein 2 provided an understanding of the complex metabolic impairment involved in this syndrome. We report the first family with modified clinical expression of Dubin-Johnson heterozygous state due to genotypic interaction with co-inherited beta and deltabeta thalassaemia, an interaction that has never been described.