P-556 Genetic variation in genes related to folliculogenesis and steroidogenesis in Caucasian and Asian women: Baby steps towards a pharmacogenetic approach in assisted reproductive techniques
Authors: Neves A  R , Casarini L , Garcia S , Vuong N  L , Blockeel C , Simoni M , Polyzos N  P 
Published: July 2024

Abstract

Study question
What is the impact of single nucleotide polymorphisms (SNPs) in genes related to the folliculogenesis and steroidogenesis on ovarian response to stimulation?

Summary answer
SMAD2 rs13381619 and COMT rs4680 variants are associated with the follicular output rate (FORT).

What is known already
The prediction of ovarian response (OR) is crucial for an optimal and individualized management. Despite the good accuracy of ovarian reserve markers in the prediction of OR, a proportion of patients are unexpected hypo-responders. Therefore, a link between OR and individual genotype has been suggested. However, the available evidence is limited by small sample sizes and heterogeneous study designs, including patients with different profiles and allowing for dose adjustments during treatment. Our aim was to analyze the association between SNPs in genes related to folliculogenesis and steroidogenesis and OR in an ethnic diverse population treated with the same fixed-dose protocol.

Study design, size, duration
This is a secondary analysis of a multicenter multinational prospective study, including 368 patients from Vietnam, Belgium, and Spain (168 from Europe and 200 from Asia) recruited from 11/2016-06/2019. The study included predicted normal responders &lt;38 years old undergoing their first or second ovarian stimulation (OS) cycle. All patients underwent OS in an antagonist protocol with a fixed daily dose of 150 IU rFSH until triggering.

Participants/materials, setting, methods
First, an interactome was developed using “FSHR” and “LHCGR” as keyword imputed in the Homo sapiens STRING database for protein network analysis. Genetic information from sixty-eight final SNPs involved in the folliculogenesis and steroidogenesis was obtained and used for clustering analysis. Secondly, genotype-phenotype analysis was performed. The prevalence of hypo-responders (&lt;10 oocytes retrieved), number of oocytes retrieved, FORT and follicle to oocyte index (FOI) were compared between different SNPs genotypes.

Main results and the role of chance
Clustering analysis revealed four distinct genetic clusters according to the selected SNPs related to folliculogenesis and steroidogenesis. Principal component analysis (PCA) was used to display individuals’ distribution according to the fertility centre, resulting in an obvious distribution according to ethnicity. However, PCA failed to demonstrate a clinically significant association between our interactome and the outcomes of interest. We further refined our SNP panel by categorizing SNPs according to their physiological pathway and analyzed their individual impact on OR. Following multivariable linear regression adjusting for patient’s age, Anti-Mullerian hormone (AMH), duration of stimulation and ethnicity, SMAD2 rs13381619 genotype GC (estimated mean difference (EMD) 11.57, 95% Confidence interval (CI) 2.66-20.49), and COMT rs4680 genotype AA (EMD 18.31, 95% CI 4.91-31.72) were associated with improved FORT. No impact of the studied polymorphisms was found on the prevalence of hypo-response, number of oocytes retrieved nor FOI.

Limitations, reasons for caution
The study was performed in young women with a normal ovarian reserve to eliminate biases related to age-related fertility decline, precluding the extrapolation of the results to other populations. Moreover, the low prevalence of some genotypes might have limited the analysis of some of the included variants.

Wider implications of the findings
Our findings confirm the variation of SNPs prevalence according to ethnic diversity, highlighting the importance of the intercontinental design of our study. Moreover, a novel association between SMAD2 and COMT variants and OR was reported, opening new opportunities for further pharmacogenetics studies and paving the way towards personalized medicine.

Trial registration number
Not applicable