Three Novel Single Nucleotide Polymorphisms of UGT1A9in a Thai Population

The human UDP-glucuronosyltransferase, UGT1A9, catalyzes glucuronidation of various endobiotics and xenobiotics. In this study, we sequenced the promoter and exon 1 regions of the UGT1A9gene in 93 Thai individuals and identified 7 genetic polymorphisms. The allele frequencies of all 3 novel single nucleotide polymorphisms (SNPs): 454A>G and 455A>C (N152A) and 760C>T (R254X) were 0.005. The other 4 known polymorphisms, −688A>C, −440T>C, −331C>T and −118A(T)1<,AT (UGT1A9* 1b), were identified and found to have frequencies of 0.124, 0.978, 0.968 and 0.532, respectively.