Association of Serum Resistin Level and Resistin (RETN) Gene (-420C>G) Polymorphism in Pakistani Women with Polycystic Ovarian Syndrome

Abstract

Objective: The objective of the present study was to investigate the association of altered serum resistin levels to RETN gene (420C>G) polymorphism in women with polycystic ovarian syndrome (PCOS) and in healthy controls. Material and Methods: Eighty (40 PCOS cases and 40 healthy controls) individuals were included. Whole blood and serum samples were taken from all participants. Enzyme linked immunosorbent (ELISA) was performed for measuring the levels of serum resistin. Whole blood was used for extracting total genomic DNA by the phenol-chloroform method. Polymerase chain reaction with fragment length polymorphism was performed for detecting single nucleotide polymorphism (SNP) in the promoter region (-420 C>G) of the resistin (RETN) gene by amplifying the oligonucleotide sequence of the SNP. The amplified products were first confirmed on 2.0% agarose gel for product size, and then restriction digestion of these products was performed by using the Bpil restriction enzyme. After completion of digestion, the products were resolved on 2.5% agarose gel with a 100 bp DNA ladder, and the bands were inspected to infer genotype. Data analysis was done using SPSS software and the association between serum resistin levels and RETN genotypes was analyzed. Results: There was no significant difference (p=0.125) observed in serum resistin levels between PCOS cases (mean±SD=19.33±3.50) and healthy controls (mean±SD= 13.48±1.31). The frequency of the G allele was high in PCOS cases (65%) than in controls (53.7%). The GG genotype frequency of SNP (-420 C>G) was high in PCOS cases (40%) than in controls (20%), but no association was found (p=0.148). The high serum resistin levels were significantly associated with the GG genotype in PCOS cases (p=0.027). Conclusion: High serum resistin levels are not associated with the genotypes of RETN (-420 C>G) polymorphism in PCOS women and controls, although women with PCOS had high GG genotype levels of serum resistin. Further studies with large sample size should be conducted to explore the mechanism of genetic factors in complex diseases like PCOS.