Intron-specific Single Nucleotide Polymorphisms of Fat Mass and Obesity- Associated Gene in Obese and Overweight Individuals of the Indian Adult Population- A Pilot Study.

Background: The Fat mass and obesity-associated gene (FTO) and its involvement in weight gain and obesity is well-known. However, no reports have been published on the Indian population regarding the relationship between single nucleotide polymorphisms (SNPs) in its intronic region and obesity. The aim of this pilot study was to evaluate the frequency and association of SNPs in intron-1 of the FTO gene in obese and overweight Indian adults.

Methods: This study group consisted of 80 adults, aged 23.5 ± 8.9 yr, with a mean BMI of 28.8 ± 6.2 kg/m2. Genomic DNA was isolated, exons1-3 & intron1 of FTO were amplified using polymerase chain reaction and sequenced by ABI sequencing detection system. The reported SNPs rs1420185, rs8050136, rs1121980 and rs55872725 were checked for their presence or absence in this group of the adult Indian population.

Results: No mutations were found in the exonic sequence of FTO, however, the association of rs1420185, rs8050136, rs1121980 and rs55872725 SNPs was identified in this population. The genotypic frequency at FTO rs8050136 was 32.2% for C>A, at rs55872725 it was 45.7% for C>T, at rs1420185 it was 27.1% for T>C and at rs1121980 it was 30.5% for G>A. All four SNPs in combination were observed in 6 participants (10.2%), all of whom were found to be either obese or overweight.

Conclusion: These findings indicate that Indians with these SNPs are most likely to be at increased risk of obesity.