Analysis of SNPs of MC4R , GNB3 and FTO gene polymorphism in obese Saudi subjects.

Said Salama Moselhy1,4,6,7*, Yasmeen A Alhetari1, Archana Iyer1,4,5, Etimad A Huwait1,
Maryam A AL-Ghamdi1, Shareefa AL-Ghamdi1, Khadijah Saeed Balamash1, Ashraf A Basuni2,8,
Mohamed N Alama3, Taha A Kumosani1,4,5, Soonham Sami Yaghmoor4,5
1. Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia.
2. Department of Biochemistry, Faculty of Medicine, King Abdulaziz University (Rabigh), Kingdom of Saudi Arabia.
3. Consultant cardiologist, King Abdulaziz University hospital, Jeddah, Kingdom of Saudi Arabia.
4. Experimental biochemistry Unit, King Fahd Medical Research Center (KFMRC), KAU, 80216 Jeddah 21589, Saudi
Arabia.
5. Production of natural products for industerial health Resaerch Group, King Abdulaziz University, Jeddah,
Kingdom of Saudi Arabia.
6. Bioactive natural Research Group,King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia.
7. Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo, Egypt.
8. Department of Biochemistry, Liver Institute, Menofya University, Egypt.

Abstract
Background: The goal of this study was to analyze the association between the FTO rs17817449 (G>T), G protein beta3
subunit (GNB3) C825T and Melanocortin 4 receptor (MC4R) A822G single nucleotide polymorphism (SNP) with obesity in
Saudi subjects.

Methods: The subjects were divided into 2 groups according to BMI: Obese (BMI> 29.9) and non- obese control (BMI<24.9).
Genotyping of the target genes were determined by polymerase chain reaction (PCR) followed by restriction fragment length
polymorphism analysis (RFLP).

Results: We demonstrated the association of the FTO genotype TT with increased weight, BMI and leptin levels in both males
and females. However, there was no association of genotype TT with fasting blood glucose, triglycerides and cholesterol levels.
Regarding GNB3 rs5443 polymorphism, the likelihood of obesity was linked to the TT genotype which was also associated with
increased leptin levels. On the other hand, the SNP of MC4R A822G did not exhibit any signifcant association with obesity
among studied subjects and showed only the presence of homozygous AA genotype.

Conclusion: The polymorphism of FTO gene rs17817449 and GNB3 gene rs5443 (C825T) may be a genetic determinant of
obesity in Saudi population whereas impact of MC4R Asn274Ser change could not be detected.

Keywords: Obesity, FTO gene-polymorphism.