Implementation of a New Genetic Screening Test for of Genetic Recessive Diseases in a Program of Oocyte Donation

Abstract

BackgroundCurrent screening for carriers of genetic diseases in oocyte donors includes the assessment of risk of transmission of inherited diseases based on personal and family history of genetic disorders. Most assisted reproduction centers also include karyotyping, mutational screening of the CFTR gene and directed the study of fragile X premutation. Next generation sequencing (NGS) technologies of have allowed to expand genetic screening to a large number of diseases at a reasonable cost.Objective • Develop a new genetic test (qCarrier) based on NGS technology for extended recessive diseases in the field of reproductive medicine screening. • Implementation of the carrier screening test in our oocyte donation program.Material and MethodsThe test covers 200 genes (68 in full sequence analysis and targeted screening of 132 known mutations) associated with autosomal recessive diseases 185 (AR) and 11 linked to chromosome X. The test was developed by NGS technology and allows characterization of a broad spectrum of mutations (point, indels, rearrangements and CNVs). The expanded carrier screening is performed on all candidate of oocyte donors and on the male partner of the recipient of oocytes. We discard from the oocyte donor program all candidates that are carriers of X-linked disease. The heterozygous carrier status for an autosomal recessive condition is no a reason for exclusion as a donor, but it involves the selection of a recipient whose male partner is not a carrier of disease mutations in the same gene.ResultsThe validation of the test showed high sensitivity (>99%). It has made the extended carrier screening a total of 445 oocyte donor candidates and a total of 587 male partners of oocyte recipients. The implementation of the test in our OD program has identified 57% of patients/donors carriers least a pathogenic mutation.Conclusions • The implementation of the test in oocyte donors program has identified a 3% allocation at high risk of disease autosomal recessive. Two percent of donor candidates to enter the oocyte donors program are carriers of pathogenic mutations linked to the X chromosome. • The expanded carrier screening is a useful tool to reduce the rate of newborns affected of genetic diseases in children born through oocyte donors program. • The implementation of the test in clinical settings requires pre and post-test genetic counseling to ensure adequate information, consent of patients and safeguard the fundamental ethical issues facing patients and oocyte donors.