O-303 Contribution of targeted sequencing for genetic diagnosis of premature ovarian insufficiency in clinical practice
Authors: Sassi A , Okutman O , Marangoni M , Van Dooren S , Gheldof A , Alvaro Mercadal B , Pintiaux A , Abramowicz M , Desir J , Delbaere A 
Published: June 2023

Abstract

Study question
What is the diagnostic yield of custom designed gene panel for patients with premature ovarian insufficiency (POI)?

Summary answer
The diagnostic yield of our POI gene panel (POIGP) is 7.3%

What is known already
POI is a specific female syndrome with a high clinical and genetic heterogeneity. It is characterized by a premature exhaustion of the ovarian function and infertility and affects approximately 1% of women. POI can be related to genetic factors which include chromosomal abnormalities, FMR1 premutation and rare variants in numerous genes. The advent of high throughput sequencing methods has led to the identification of an increasing number of variants implicated in the development of POI over the last decades. However, POI etiologies still remain undetermined in the majority of cases.

Study design, size, duration
An observational analytic cohort study of 150 patients presenting idiopathic POI (normal karyotype, absence of FMR1 premutation, absence of adrenal and/or ovarian antibodies) recruited prospectively at three Belgian academic and university hospitals between 2016 and 2021.

Participants/materials, setting, methods
Patients were included if they experienced POI, as defined by ESHRE guidelines on POI (2016). POI genes included in the panel were selected from PubMed using different key words mainly premature ovarian insufficiency, gonadal dysgenesis, hypergonadotropic hypogonadism, ovarian failure and genetics. The panel included 156 genes, variants were filtered based on allele frequency (≤1%) in latest available population databases and classified according to ACMG/AMP (American College of Medical Genetics/Association for Molecular Pathology) guidelines 2015.

Main results and the role of chance
Our analysis revealed a potential causative variant for 11 patients in the following genes: MEIOB, BMP4, CFTR, FANCA, FSHR, FANCG, MLH1, MRPS22 and STARD9. This means that the diagnostic yield of our POI gene panel (POIGP) is 7.3%.
Patients were mainly Caucasian (63%), North African (17%) and sub-Saharan African (13%). They presented primary amenorrhea in 14.7% of cases. Consanguinity and/or a family history of POI or early menopause in 28% of cases. Mean patient’s age (years) at POI diagnosis was 28.9± 8.5 (mean ± SD). The overall mean coverage was 229X, and more than 95% of the target exome was represented with more than 30-fold coverage.

Limitations, reasons for caution
The present study was limited to monogenic etiologies of POI, potential oligogenic causes have not been searched. Functional studies and/or family segregation were not performed for the identified variants.

Wider implications of the findings
Our findings show the importance of targeted next generation sequencing in clinical practice and highlight the limit of our current genetic knowledge in the field of POI. A regular update of genes included in POIGP will improve its diagnostic yield.

Trial registration number
P2016/196/CCB B406201628264