Idiopathic cholestasis of pregnancy in a large kindred.

A past history of idiopathic cholestasis of pregnancy (ICP) was detected in 10 out of the 32 multiparous women in the last two generations of a large kindred. The affected women are distributed in five family units, sharing Chilean-born great-grandparents. The connection between the ICP-affected women and the common trunk is given both by male and female parents. Five cases are concentrated in one family unit, where the mother and all her daughters have been affected by the disease. The role of genetic factors in the pathogenesis of ICP is supported by this study. It is proposed that the disease may be transmitted as a predisposing trait by individuals of either sex and that non-genetic factors may influence its expressivity. A reliable test to identify all the genetic carriers seems indispensable to define the pattern of inheritance in this disease.