# Genetic study on candidates for oocyte donation

## TL;DR

This study examines the genetic screening of oocyte donors to identify hereditary risks and determine eligibility for donation.

## Contribution

The study provides empirical data on the prevalence of genetic disorders among oocyte donors in a specific clinic over a nine-year period.

## Key findings

- 81 out of 581 donors were excluded due to genetic abnormalities or carrier status.
- Common exclusions included Cystic Fibrosis, Fragile X syndrome, and Spinal Muscular Atrophy.
- The study highlights the importance of genetic testing and counseling in 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 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 who underwent genetic testing 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, Fragile
X syndrome and Spinal Muscular Atrophy 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 pathogenic variant or had a 5T
allele, 11/394 had Survival of Motor Neuron 1 deletion and 8/426 had an
intermediate or premutation allele in Fragile X Messenger Ribonucleoprotein
gene. While recommendations from fertility societies advocate for
comprehensive screening, opinions differ on the mandatory implementation of
expanded carrier screening.

In conclusion, the genetic tests and the pre and post-test counseling is
imperative to optimize reproductive outcomes in the oocyte donation
process.