Single Nucleotide Polymorphism in FTO rs9939609 and Obesity Among Asians and Caucasians: A Meta-Analysis

Scope: FTO is now confirmed as the gene responsible for obesity but epidemiological studies showed various results based on different locations in the gene and in which ethnic group the polymorphism was found. The objective of this meta analysis was to contrast reports on FTO and obesity association among Asian and Caucasian ancestries. Methods and Results: This study was done by a literature search from PUBMED using a combination of terms of “FTO”, “obesity”, “BMI”, “weight” and “waist circumference” between January 2007 and February 2012. Observation studies were collected from several countries in Europe and North America reflecting Caucasian ethnic group and countries in South, East and South East Asia reflecting Asian ethnic group. FTO rs9939609 was the most studied loci. The minor allele frequency (MAF) of A allele of rs9939609 in Asians (es=24.77; 95%CI=20.91-28.63; I2=60.79%) was lower as compared to Caucasians (es=41.03; 95% CI=40.48-41.68; I2=0%). The OR for obesity of rs9939609 SNP was not different between Asians (es=1.31; 95%CI=1.12-1.49; I2=0%) and Caucasians (es=1.27; 95%CI=1.18 - 1.36; I2=31.65%). Conclusion: Although Caucasians have higher minor allele frequency (MAF) of FTO rs9939609 than Asians, the effect of this SNP on obesity is similar. This might explain higher prevalence of obesity in Caucasians.