Karyomapping in preimplantation genetic testing for β-thalassemia combined with HLA matching: a systematic summary

J Assist Reprod Genet. 2019 Dec;36(12):2515-2523. doi: 10.1007/s10815-019-01595-7. Epub 2019 Nov 22.

Abstract

Purpose: To investigate the validity, accuracy, and clinical outcomes of Karyomapping in preimplantation genetic testing (PGT) for β-thalassemia combined with human leukocyte antigen (HLA) matching.

Methods: A total of 128 cycles from January 2014 to December 2017 were identified, and 1205 embryos were biopsied. The case group included 88 cycles using Karyomapping for PGT-HLA, compared with 40 cycles using polymerase chain reaction-short tandem repeat (PCR-STR) as the control group.

Results: There were significant differences in the HLA matching rate (21.34 vs. 14.37%), the matched transferable embryo rate (9.79 vs. 14.07%), the clinical pregnancy rate (65.08 vs. 41.86%), and the spontaneous miscarriage rate (2.44 vs. 22.22%) between the case and control groups. In the case group, nearly 1/3 (33.37%) of the embryos showed aneuploidy. According to the results of single nucleotide polymorphism (SNP) haplotype analysis, the recombination rates of HBB (hemoglobin subunit beta) and HLA were 11.46% and 5.61% respectively. HLA gene recombination was mostly distributed between HLA-A and HLA-B and the downstream region of HLA-DQB1. In addition, STR analysis could be considered in the case of copy-neutral loss of heterozygosity (LOH) in the region where the HLA gene is located.

Conclusion: Karyomapping contributes to accurate selection of matched embryos, along with aneuploidy screening. However, STRs assist identification in cases of LOH in the target region.

Keywords: Genetic testing; HLA matching; Karyomapping; Preimplantation; β-Thalassemia.

MeSH terms

  • Adult
  • Biopsy
  • Embryo Transfer
  • Female
  • HLA-A Antigens / genetics*
  • HLA-B Antigens / genetics*
  • HLA-DQ beta-Chains / genetics
  • Hemoglobin Subunits / genetics
  • Humans
  • Karyotyping / methods*
  • Loss of Heterozygosity / genetics
  • Pregnancy
  • Pregnancy Rate
  • Preimplantation Diagnosis*
  • beta-Thalassemia / diagnosis*
  • beta-Thalassemia / genetics
  • beta-Thalassemia / pathology

Substances

  • HLA-A Antigens
  • HLA-B Antigens
  • HLA-DQ beta-Chains
  • HLA-DQB1 antigen
  • Hemoglobin Subunits