Molecular basis of inherited bilirubin disorders in pediatrics

Jaundice in an infant or older child may reflect accumulation of either unconjugated or conjugated bilirubin and could be related to inherited bilirubin disorders. In this review we will consider some new insights related to bilirubin metabolism, particularly the molecular approach to inherited bilirubin disorders. Within this context the enzyme UGT1A1 plays a central role and three clinical conditions appear related with mutations in this gene: Crigler-Najjar type I, type II and Gilbert’s syndrome. The last one is found in all the populations examined with a 5-18% prevalence. This high prevalence makes Gilbert’s syndrome a polymorphic entity able to influence other Mendelian conditions (ie. thalassemia, inherited spherocytosis); such association can affect the level of serum bilirubin and the risk of gallstones