Identification of the G994T polymorphism in exon 9 of plasma platelet-activating factor acetylhydrolase gene as a risk factor for polycystic ovary syndrome.

BACKGROUND

Low-grade chronic inflammation and greater risks of cardiovascular diseases are often present in patients with polycystic ovary syndrome (PCOS). Platelet-activating factor (PAF) acetylhydrolase (PAF-AH) hydrolyzes and inactivates PAF and PAF-like oxidized phospholipids that are potent lipid mediators involved in inflammation and atherosclerosis. Deficiency of this enzyme is caused by a missense mutation (G994 --> T) in exon 9 of the plasma PAF-AH gene. The aim of the study was to investigate a possible association of this polymorphism with the risk of PCOS and to evaluate the effects of the genotype on the activity and distribution of PAFAH in Chinese patients.

METHODS

A total of 661 subjects (346 patients with PCOS and 315 healthy control women) from a population of Chinese Han nationality in Chengdu area were included in this study. PAFAH G994T genotype was studied using PCR and restriction fragment length polymorphism analysis. Total plasma PAF-AH, high-density lipoprotein (HDL)-associated PAF-AH (H-PAF-AH) and low-density lipoprotein (LDL)-associated PAF-AH (L-PAF-AH) activities were measured by the trichloroacetic acid precipitation procedure using [(3)H-acetyl] PAF and PAF C-16 as a substrate.

RESULTS

The prevalence of the mutant genotype (GT + TT) was significantly more frequent in patients with PCOS than in control subjects (12.7 versus 6.0%, P = 0.003). Genotype (GT + TT) remained a significant predictor for PCOS (P = 0.020) in prognostic models including age, body mass index, insulin resistance index, triglyceride, HDL and LDL as covariates. There was a significant difference in plasma PAF-AH, L-PAF-AH and H-PAF-AH activities between GG and GT genotypes in both the patient and control groups. The ratio of L-PAF-AH to H-PAF-AH activities was significantly higher after adjustment for multiple variables in patients with GT genotype compared with patients with GG genotype (P = 0.003). There were no significant differences in clinical, biochemical and metabolic parameters according to PAFAH G994T genotyping in patients with PCOS and control women.

CONCLUSIONS

The G994T polymorphism in PAFAH gene may be one of the genetic determinants for PCOS in Chinese Han women.