Pyruvate kinase deficiency as a cause of extreme hyperbilirubinemia in neonates from a polygamist community

Neonatal hemolytic jaundice is a risk factor for kernicterus. pyruvate kinase (pk) deficiency is a rare cause of neonatal hemolytic jaundice, with a prevalence estimated at 1 case per 20 000 births in the united states, but with a higher prevalence among the amish communities in pennsylvania and ohio. we discovered four neonates with pk deficiency born in a small community of polygamists. all four had early, severe, hemolytic jaundice. pk deficiency should be considered in neonates with early hemolytic, coombs-negative, non-spherocytic jaundice, particularly in communities with considerable consanguinity. such cases should be recognized early and managed aggressively to prevent kernicterus.