A Decade of Molecular Preimplantation Genetic Diagnosis of 350 Blastomeres for Beta-Thalassemia Combined with HLA Typing, Aneuploidy Screening and Sex Selection in Iran

Abstract

Background: Preimplantation genetic diagnosis (PGD) has been developed to detect genetic disorders before pregnancy which is usually done on blastomeres biopsied from 8-cell stage embryos obtained from in vitro fertilization method (IVF).

Here we report molecular PGD results for diagnosing of beta thalassemia (beta-thal) which are usually accompanied with evaluating chromosomal aneuploidies, HLA typing and sex selection.

Methods: In this study, haplotype analysis was performed using short tandem repeats (STRs) in a multiplex nested PCR and the causative mutation was detected by Sanger sequencing.

Results: We have performed PGDs on 350 blastomeres from 55 carrier couples; 142 blastomeres for beta-thal only, 75 for beta-thal and HLA typing, 76 for beta-thal in combination with sex selection, and 57 for beta-thal and aneuploidy screening. 150 blastomeres were transferable, 15 pregnancies were happened, and 11 babies born.

We used 6 markers for beta-thal, 36 for aneuploidy screening, 32 for sex selection, and 35 for HLA typing. To our knowledge combining all these markers together and the number of STR markers are much more than any other studies which have ever done.

Conclusions: PGD is a powerful diagnostic tool for carrier couples who desire to have a healthy child and wish to avoid medical abortion.