UGT1A6 and cholelithiasis: Fifteen SNPs in UGT1A1, UGT1A3, UGT1A4, UGT1A5, UGT1A6, UGT1A7, UGT1A8 and UGT1A9 reached genome-wide significance for association with total bilirubin levels in the CSSCD cohort; 13 of these were also associated with the presence or history of cholelithiasis.