Due to the strong linkage disequilibrium between the rs4148325 variant and the UGT1A1*28 allele (r2 = 0.88 and D′ = 0.98) [11], the majority of rs4148325 TT homozygotes likely have Gilbert’s syndrome, with lower gene expression and diminished bilirubin metabolism. The gene discussed is UGT1A1; the disease is Gilbert syndrome.