title: Differences in frequencies of UGT1A9, 1A7, and 1A1 genetic polymorphisms in Chinese Tibetan versus Han Chinese populations.
abstract: As part of a series of pharmacogenomics studies of the Chinese population, we investigated genetic polymorphisms of some UGT1A regions. The three genes that were analyzed were UGT1A9, 1A7, and 1A1; we sequenced their exons, together with promoters, surrounding introns and 3'-untranslated regions (3'UTR) in 100 unrelated-healthy Chinese Tibetan individuals. We compared the data with information on Han Chinese of the same region, which we downloaded from the HapMap database. We identified 40 polymorphisms; 16 of them were shared by the two populations. We then analyzed their linkage disequilibrium map. The UGT1As cluster can be divided into two linkage blocks in the Tibetan population: Block 1 (UGT1A9, UGT1A7), Block 2 (3'-UTR). Furthermore, we identified haplotypes and selected their tagSNPs. In exon 1 of UGT1A7 gene, 393G>A (Arg131Gln, rs17868324) was found at a frequency of 44.4% in the Tibetan population, compared to only 0.7% in the Han population. The linkage blocks in the Han Chinese sample differed from that of the Chinese Tibetan group; the former had Block 1 (UGT1A9, UGT1A7), Block 2 (UGT1A7), and Block 3 (3'-UTR). These findings provide fundamental information for future molecular genetic studies of the UGT1A gene cluster as well as for personalized medicine in Chinese.
authors.affiliation: National Engineering Research Center for Miniaturized Detection System, College of Life Sciences, Northwest University, Xi'an, Shaanxi, China.
authors.forename: W
authors.initials: W
authors.lastname: Yan
authors.forename: Y W
authors.initials: YW
authors.lastname: Wang
authors.forename: F F
authors.initials: FF
authors.lastname: Yang
authors.forename: M
authors.initials: M
authors.lastname: Wang
authors.forename: X Q
authors.initials: XQ
authors.lastname: Zhang
authors.forename: J
authors.initials: J
authors.lastname: Dong
authors.forename: E
authors.initials: E
authors.lastname: Chen
authors.forename: J
authors.initials: J
authors.lastname: Yang
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000483:Alleles; D001483:Base Sequence; D002681:China; D005006:Ethnicity / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D014453:Glucuronosyltransferase / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics; D008297:Male; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic / Q000235:genetics; D017422:Sequence Analysis, DNA; D018609:Tibet; D000090264:UDP-Glucuronosyltransferase 1A9; D055815:Young Adult; D000099148:UGT1A1 Enzyme
chemical_list: D020413:3' Untranslated Regions; D014453:Glucuronosyltransferase; D000090264:UDP-Glucuronosyltransferase 1A9; D000099148:UGT1A1 Enzyme; C000715591:UGT1A9 protein, human; C524630:UGT1A7 protein, human