Congenital bile duct dilatation--possibly an hereditary condition.

A female patient underwent resection of a large choledochal cyst and hepaticojejunostomy when she was 11 years old at Tokyo Medical and Dental University Hospital. Her mother, 48 years old, also had congenital bile duct dilatation (CBD) with cancer. The mother had an anomalous pancreatico-biliary ductal junction. To investigate the possibility of a genetic link, family members of another three consecutive CBD cases were examined for bile duct dilatation and anomalous pancreatico-biliary junction. Endoscopic retrograde choledocho-pancreatography (ERCP) revealed an anomalous pancreatico-biliary ductal junction, without bile duct dilatation in the mother of a 17-year-old CBD patient. Two familial occurrences of CBD had been reported in the Japanese literature. Their combinations were; a father--a daughter and two sisters, respectively. Considering that the sex ratio of CBD is one male to 2.6 females, our results suggest that CBD or anomalous pancreatico-biliary ductal junction may be 1) an X-linked dominant trait or 2) autosomal dominant trait with relatively low penetrance in males. Since anomalous pancreatico-biliary ductal junction does not necessarily develop into bile duct dilatation, more familial investigations on pancreatico-biliary ductal junction and bile duct dilatation are essential to clarify the genetic contribution to CBD.