Successful four-factor preimplantation genetic testing: α- and β-thalassemia, human leukocyte antigen typing, and aneuploidy screening

ABSTRACT

Our study established an effective next-generation sequencing (NGS) protocol for four-factor preimplantation genetic testing (PGT) using  α- and β-thalassemia, human leukocyte antigen (HLA) typing, and aneuploidy screening. Three couples, in whom both partners were α- and β-double thalassemia carriers, underwent PGT between 2016 and 2018. These individuals sought an opportunity for hematopoietic stem cell transplantation to save their children from β-thalassemia major. A total of 35 biopsied trophectoderm samples underwent multiple displacement amplification (MDA). PGT for α- and β-thalassemia and HLA typing were performed on MDA products using NGS-based single-nucleotide polymorphism (SNP) haplotyping. Although two samples failed MDA, 94.3% (33/35) of samples were successfully amplified, achieving conclusive PGT results. Furthermore, 51.5% (17/33) of the embryos were diagnosed as unaffected non-carriers or carriers. Of the 17 unaffected embryos, nine (52.9%) were tested further  and identified as euploid via NGS-based aneuploid screening, in which five had HLA types matching affected children. One family did not achieve any unaffected euploid embryos. The two other families transferred HLA-matched and unaffected euploid embryos, resulting in two healthy ‘savior babies.’ NGS-PGT results were confirmed in prenatal diagnosis. Therefore, NGS-SNP was effective in performing PGT for multipurpose detection within a single PGT cycle.

KEYWORDS:

• Thalassemia
• human leukocyte antigen typing
• next-generation sequencing
• preimplantation genetic testing

Acknowledgments

The authors thank Taylor & Francis Editing Services for providing the English polish.

Disclosure statement

The authors report no conflicts of interest.

Ethics approval

The Research Ethics Committee of the First Affiliated Hospital of Sun Yat-sen University approved our study. Written consent from three families was obtained before the study commenced.

Author contributions

Protocol design: DC, XS, YX; Patient counseling: YX; Execution: XS, YX, CD, QY; Manuscript preparation: DC, XS; Manuscript revision: Y-WX, YZ, CZ; Supervision: CZ.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This study was supported by the Guangdong Provincial Key Laboratory of Reproductive Medicine [2012A061400003] and the Guangzhou Science and Technology Project: Development and Application of The Reagents for Preimplantation Diagnosis and Screening by Next-Generation Sequencing [201704020217]. , the National Key R&D Program of China [2016YFC1000205], the National Natural Science Foundation of China [32000589], and the Guangdong Basic and Applied Basic Research Foundation [2114050000636].