UGT1A1 and Gilbert syndrome: Several polymorphisms in the UDP-GT family 1 member A1 (UGT1A1) gene, on chromosome 2, have been associated with Gilbert’s syndrome, but the most common one is a TATA box polymorphism (rs8175347), consisting of a (TA)5–7 repeat within the UGT1A1 promoter designated UGT1A1*28 [27].