UDP glucuronosyltransferase family 1 member A1 (UGT1A1, OMIM entry number * 191740), on chromosome 2q37, encodes the UGT1A1 enzyme, which plays a key role in bilirubin conjugation; the levels of UGT1A1 are reduced in individuals with GS. Here, UGT1A1 is linked to Gerstmann syndrome.