Genetic study on candidates for oocyte donation

Abstract

There is a rising demand for assisted reproductive medicine, including sperm, oocyte and embryo donation. Besides medical and legal considerations, genetic testing, including carrier screening (CS) for multiple autosomal and X-linked recessive disorders plays an essential role in evaluating hereditary risk among donors and therefore exclude them from the donation process. A retrospective study was conducted on oocyte donors from a private clinic of assisted reproduction between June 2014 and September 2023. Pre and post-test procedures were performed at the private clinic while karyotyping and carrier screening for Cystic Fibrosis (CF), Fragile X syndrome and Spinal Muscular Atrophy (SMA) were performed at the Genetic Unit of Faculty of Medicine, University of Porto. Among 581 donors, 81 women were excluded from the donation process since 5/563 had an alteration in karyotype, 57/581 were carriers of a Cystic Fibrosis Transmembrane conductance Regulator (CFTR) pathogenic variant or had a 5T allele, 11/394 had Survival of Motor Neuron 1 (SMN1) deletion and 8/426 had an intermediate or premutation allele in Fragile X Messenger Ribonucleoprotein (FMR1) gene. While recommendations from fertility societies advocate for comprehensive screening, opinions differ on the mandatory implementation of expanded carrier screening (ECS). In conclusion, the genetic tests and the pre- and post-test counseling is imperative to optimize reproductive outcomes in the oocyte donation process.