rs4889 polymorphism in KISS1 gene, its effect on polycystic ovary syndrome development and anthropometric and hormonal parameters in Saudi women

BACKGROUND: Kisspeptin is involved in female reproduction. This study was designed to i- estimate kisspeptin levels in women with polycystic ovary syndrome (PCOS), in comparison with controls, ii- study the correlations between kisspeptin and PCOS-related reproductive hormones, and iii- investigate the relation between KISS1 gene polymorphisms and hormone levels in women suffering from PCOS. METHODS: The investigation was a clinically designed study on 28 women with PCOS, and 30 normal, healthy women with no signs of PCOS as controls. Blood samples were collected between day 3 and day 6 of the menstrual cycle in both groups at 8:00 a.m., and circulating levels of LH, FSH and kisspeptin were estimated. DNA was extracted from whole blood and all coding exons of KISS1 gene were sequenced. RESULTS: Women with PCOS had higher LH levels and BMI compared to controls. Plasma kisspeptin levels were positively correlated with LH levels. There was no statistically significant difference between the groups in terms of kisspeptin and FSH levels. The SNP rs4889 C/G, a non-synonymous SNP, was investigated in the PCOS group. The frequency of GG genotype was significantly higher in the PCOS compared to the controls. These patients were more obese, had higher kisspeptin and FSH levels. CONCLUSION: The results of the study show that the genetic variation of KISS1 gene may be a factor contributing to PCOS development. The association between the gene and the gene variation and PCOS need further validation in large-scaled and functional studies.