Expanding families: a pilot study on preconception expanded carrier screening in Bahrain.

Abstract

Background: Preconception expanded carrier screening (ECS) is a genetic test that enables the identification of at-risk carriers of recessive disorders by screening for up to hundreds of genes. Next-generation sequencing (NGS) development has paved the way for its integration into ECS. This study aims to identify the carrier genetic status of couples experiencing or anticipating conception challenges through NGS-based ECS and to gain an overview of the rare genetic disorders in a population with increased consanguinity.

Methods: Thirty couples who presented to the Genetic Disease Clinic between 2015 and 2024 with failed reproductive outcomes or with a positive personal or family history of genetic disorders and underwent ECS were included and retrospectively analyzed.

Results: Fifty-four individuals (90.00%) were found to carry at least one variant of 95 identified genes, totaling 174 variants. Six individuals (10.00%) tested negative for any variant. Seven individuals had one variant (11.67%), 13 had two variants (21.67%), and 34 had 3 or more variants (56.67%). The most common variants identified were of HBA, HBB, CYP21A2, and G6PD genes. Most of the detected variants were unknown or unexpected (n = 143, 82.18%). Eight couples carried two or more variants in common. Consanguinity was reported in 14 couples (46.67%).

Conclusions: Preconception ECS is crucial for reproductive planning, permitting couples to evaluate their combined genetic risks and make informed decisions, reducing the chance of having children with genetic disorders.