RESUMO
<p><b>BACKGROUND</b>Genome-wide association studies for type 2 diabetes mellitus (T2DM) identified FTO gene as a locus conferring increased risk for common obesity in many populations with European ancestry. However, the involvement of FTO gene in obesity or T2DM related metabolic traits has not been consistently established in Chinese populations. The objective of this study was to investigate the association of FTO genetic polymorphisms with metabolic syndrome (MetS) in Han Chinese.</p><p><b>METHODS</b>We tested 41 FTO single nucleotide polymorphisms (SNPs) for association between FTO and MetS-related traits. There were a total of 236 unrelated subjects (108 cases and 128 controls), grouped according to the International Diabetes Federation (IDF) criteria.</p><p><b>RESULTS</b>Of the 41 SNPs examined, only SNP rs8047395 exhibited statistical significance (P = 0.026) under a recessive model, after Bonferroni adjustment for multiple testing (OR 1.64, 95%CI 1.11-2.42; P = 0.014). The common distributions of this polymorphism among Chinese--with a minor allele frequency (MAF) of 36% in the control group versus 48% in the MetS group--greatly improved our test power in a relatively small sample size for an association study. Previously identified obesity- (or T2DM-) associated FTO SNPs were less common in Han Chinese and were not associated with MetS in this study. No significant associations were found between our FTO SNPs and any endophenotypes of MetS.</p><p><b>CONCLUSIONS</b>A more common risk-conferring variant of FTO for MetS was identified in Han Chinese. Our study substantiated that genetic variations in FTO locus are involved in the pathogenesis of MetS.</p>