OBJECTIVETo investigate the genetic variations of the six transmembrane epithelial antigen of prostate 4 gene (STEAP4) in Chinese Uygur patients with metabolic syndrome (MetS) and to analyze the association of the representative genetic variations of STEAP4 gene with MetS in the population.

METHODSThe sequences of STEAP4 gene functional region (all exons, exon-intron boundaries and the putative promoter region, including the -1 kb 5'and 3'untranslated regions) were amplified and sequenced for patients with MetS. The representative variations were selected based on the function (missense mutation) and linkage disequilibrxium (γ² > 0.8) and genotyped with TaqMan-PCR method in 1910 general populations (682 MetS and 1228 non-MetS controls). The subjects were selected from the cross-sectional study of obesity, hypertension, diabetes, dyslipidemia from January to February 2007 among Uygur people, a relatively isolated population with a relatively homogeneous environment, in Hextian area in Xinjiang Uygur Autonomous Region.

RESULTS(1) Fourteen novel and six known single nucleotide polymorphisms (SNPs) or mutations, including 2 missense mutations, were identified at the functional region of STEAP4 gene in 96 Uygur patients with MetS. The minor allele frequencies of the SNPs of STEAP4 gene in Uygur population were different from that in European and Chinese Han in Beijing area. (2) The SNP 364G/A (rs34741656, Ala122Thr) was significantly associated with MetS [dominant model P = 0.034, OR = 0.757(95%CI: 0.584-0.982) adjusted for age and gender], and was associated with fasting blood glucose (FBG) (P = 0.049) and 2-hour postprandial glucose (2HPG) (P = 0.027) levels in controls. In this SNP, the AA carriers had lower blood glucose levels compared with subjects carrying GG and GT genotypes. (3) The common haplotype H4 (rs8122/rs1981529/ rs34741656, G-A-A), may be associated with MetS (permutation P = 0.089).

CONCLUSIONSTEAP 4 genetic polymorphisms may be associated with MetS risk in Chinese Uygur population.