Short tandem repeats haplotyping of the HLA region in preimplantation HLA matching

Abstract

Recently, preimplantation genetic diagnosis (PGD) has been considered for several indications beyond its original purpose, not only to test embryos for genetic disease but also to select embryos for a nondisease trait, such as specific human leukocyte antigen (HLA) genotypes, related to immune compatibility with an existing affected child in need of a haematopoetic stem cell (HSC) transplant. We have optimized an indirect single-cell HLA typing protocol based on a multiplex fluorescent polymerase chain reaction (PCR) of short tandem repeat (STR) markers scattered throughout the HLA complex. The assay was clinically applied in 60 cycles from 45 couples. A conclusive HLA-matching diagnosis was achieved in 483/530 (91.1%) of the embryos tested. In total, 74 (15.3%) embryos revealed an HLA match with the affected siblings, 55 (11.4%) of which resulted unaffected and 46 (9.5%) have been transferred to the patients. Nine pregnancies were achieved, five healthy HLA-matched children have already been delivered and cord blood HSCs, were transplanted to three affected siblings, resulting in a successful haematopoietic reconstruction.

Rapid protocol for pre‐conception genetic diagnosis of single gene mutations by first polar body analysis: a possible solution for the Italian patients

“…Moreover, pre-implantation HLA matching (Verlinsky et al, 2001;Fiorentino et al, 2005) would be not possible.…”

Nine polymorphic STR loci in the HLA region in the Shaanxi Han population of China

“…Studying the short tandem repeat sequences within pathogenic genes and analyzing the genetic linkage within a family has been useful for detecting the disease linked with the microsatellite markers. The STR with high polymorphism in the HLA region could be used indirectly in HLA typing in PGD and it has already become a kind of effective tool (Rechitsky et al, 2004;Fiorentino et al, 2005). To improve the accuracy of HLA typing in PGD, it has been necessary to strengthen the analysis of STRs of the HLA region, especially the polymorphic STR loci with high heterozygosity and power of discrimination.…”

Eleven years of preimplantation genetic diagnosis for human leukocyte antigen matching: is there room for improvement?

“…Subsequently, indirect HLA-haplotyping was introduced. On the basis of the linkage analysis, it provides a more generic methodology and has been the preferred approach since 2004 [3,5]. The methodological strategies used vary, some being PCR-based alone and others including an initial step of whole-genome amplification [6].…”