Polycystic ovary syndrome (PCOS), the most common endocrine disorder in women, is diagnosed based on three criteria, including a polycystic ovarian morphology. Women with PCOS have elevated serum Anti-Müllerian Hormone (AMH) levels. Furthermore, the AMH production per follicle is suggested to be higher in PCOS patients. Combined, this implies an aberrant regulation of ovarian AMH expression. However, little is known about AMH gene regulation. Hence, this study aims to investigate the regulation of AMH gene expression in PCOS patients. We have taken a genetic approach through association analysis. Associated variants were analyzed in vitro to assess their functional impact on the promoter activity.

A cohort of 700 Caucasian PCOS women were included. All two-allelic common single nucleotide polymorphisms (SNPs), located in the region Chr19:2,245,353-2,250,827bp, were selected. The analysis was performed by a linear regression model and a dominant carrier allele model. Models were adjusted for age, BMI and total follicle count. KK1 cells were used to assess the functional effects. The variants were introduced in the promoter by site-directed mutagenesis.

We assessed a total of 11 imputed SNPs. The polymorphism rs10406324 (–210 A>G) was associated with serum AMH levels in the linear regression model analysis (β = -0.52, p=6.08e-07) and dominant allele carrier model analysis (AA: 9.85ng/ml +/-0.27 (n=645) vs AG/GG: 7.60ng/ml +/-0.84 (n=54/n=1), F=16.2, p=6.48e-05). Functional analysis showed 45% lower basal activity of the -210 G variant (P=0.06). In silico analysis suggested a decrease in binding affinity of the transcription factors SF1 and ESRRA for the –210G AMH variant. Co-transfection with SF1 resulted in a similar fold increase in AMH promoter activity in both promoter variants.

In conclusion, our results showed that the human AMH promoter polymorphism –210 A>G is associated with lower serum AMH levels in Caucasian PCOS women and lead to reduced basal activity of the AMH promoter. However, replication studies and functional studies remain necessary.