Arteriohepatic dysplasia (Alagille syndrome): extreme variability among affected family members.

We describe a three-generation family in which five individuals have arteriohepatic dysplasia (Alagille syndrome) with striking differences in the degree of severity. Two sisters presented with neonatal jaundice, peripheral pulmonic stenosis, and characteristic facial appearance including a broad forehead, deep-set eyes, prominent nose, and pointed chin. One died at 5 years of cirrhosis with portal hypertension and the other at 18 months of congestive heart failure. Their asymptomatic 32-year-old mother and 35-year-old maternal aunt have a similar facial appearance, pulmonic stenosis, skeletal anomalies, and bilateral posterior embryotoxon. Neither has evidence of clinical liver disease. The maternal grandfather, who refused evaluation, has a similar appearance, a history of liver disease, and a heart murmur. Extreme intrafamilial variability has not been reported previously and most affected individuals described in the past have followed a benign course. The pattern of severity in this family suggests the possibility of a maternal factor augmenting the clinical expression in affected offspring. The skeletal anomalies and posterior embryotoxon are valuable signs in detecting asymptomatic but affected individuals who are at risk for having offspring with this potentially lethal condition.