Familial cutis tricolor: a possible example of paradominant inheritance.

Cutis tricolor is a recently described skin disorder characterized by the coexistence of congenital hyper- and hypopigmented macules adjacent to each other on a background of normal skin. It has been considered to represent an example of didymosis (twin spotting), which is a particular form of loss of heterozygosity. Cutis tricolor may occur as a cutaneous feature of various multisystem birth defects. We report two sisters with cutis tricolor. One of them had, in addition, unilateral hypoplasia of the breast. This familial occurrence of cutis tricolor may best be explained by the concept of paradominant inheritance. 2003.