VNTR I/I genotype of insulin gene is associated with the increase of follicle number independent from polycystic ovary syndrome

Abstract

We suggest that INS VNTR genotypes are not associated with PCOS in general, but could have a certain influence on the phenotypic spectrum of the syndrome.

Lack of association of INS VNTR polymorphism with polycystic ovary syndrome: a meta-analysis

“…This indicated the presence of a certain relationship between anovulation and insulin related genes. Kadri et al [24] also observed that the mean ovarian follicle number was lower in VNTR I/III and III/III individuals compared to VNTR I/I individuals, while Michelmore et al [35] also declared that both III/III genotype and paternal class III allele transmission were significantly related to the increased number of PCOS features and to reduced insulin sensitivity among women with PCO.…”

“…In total, 13 case-control studies [21][22][23][24][25][26][27][28][29][30] including 1,767 cases and 4,181 controls, were included in the analysis. Waterworth DM [21] and Powell BL [23] were conducted on the anovulatory PCOS.…”

Association of insulin gene variable number of tandem repeats regulatory polymorphism with polycystic ovary syndrome

“…The included studies were limited to those conforming to HWE and those with high NOS score (P7). Three studies [10,14,18] with relatively low NOS score (<7) and one study [10] being not in agreement with HWE (P < 0.05) were excluded. The corresponding pooled ORs were not materially altered indicating that our results were robust (Table 2).…”

“…Our initial search identified a total of 476 potentially eligible articles. Based on our inclusion criteria, a total of 8 articles were involved in this meta-analysis [10,[12][13][14][15][16][17][18]. There was perfect inter-rater reliability for the selection of studies to be included in the meta-analysis, with Kappa values of 0.834 based on titles and abstracts and 0.857 based on full texts.…”

“…Another family-based study also showed that PCOS was associated with the III alleles [11]. In addition, numerous genetic associated studies with case-control design have focused on the association of INS VNTR and POCS [10,[12][13][14][15][16][17][18]. However, results of different studies have been inconsistent, suggesting that it is unclear whether INS VNTR is associated with PCOS or not.…”