Complex preimplantation genetic diagnosis for beta-thalassaemia, sideroblastic anaemia, and human leukocyte antigen (HLA)-typing

Abstract

Preimplantation genetic diagnosis (PGD) to select histocompatible siblings to facilitate curative haematopoeitic stem-cell transplantation (HSCT) is now an acceptable option in the absence of an available human leukocyte antigen (HLA) compatible donor. We describe a case where the couple who requested HLA-PGD, were both carriers of two serious haematological diseases, beta-thalassaemia and sideroblastic anaemia. Their daughter, affected with sideroblastic anaemia, was programmed to have HSCT. A multiplex-fluorescent-touchdown-PCR protocol was optimized for the simultaneous amplification of: the two HBB-gene mutated regions (c.118C4T, c.25-26delAA), four short tandem repeats (STRs) in chr11p15.5 linked to the HBB gene, the SLC25A38 gene mutation (c.726C4T), two STRs in chr3p22.1 linked to the SLC25A38 gene, plus eleven informative STRs for HLA-haplotyping (chr6p22.1-21.3). This was followed by real-time nested PCR and high-resolution melting analysis (HRMA) for the detection of HBB and SLC25A38 gene mutations, as well as the analysis of all STRs on an automatic genetic analyzer (sequencer). The couple completed four clinical in vitro fertilization (IVF)/PGD cycles. At least one matched unaffected embryo was identified and transferred in each cycle. A twin pregnancy was established in the fourth PGD cycle and genotyping results at all loci were confirmed by prenatal diagnosis. Two healthy baby girls were delivered at week 38 of pregnancy. The need to exclude two familial disorders for HLA-PGD is rarely encountered. The methodological approach described here is fast, accurate, clinically-validated, and of relatively low cost.

Preimplantation Genetic Testing for HLA-matching: An Overview of Clinical Application and Utility

“…The most frequently requested indication for preimplantation HLA typing involves concurrent testing for beta-hemoglobinopathies. A highly multiplexed PGT-HLA protocol has been reported for this indication that supports detection of any mutation [42,43].…”

“…The probability of an affected child having an HLA-matched sibling is 25% if there is one sibling in the family. With more than one sibling the chances will increase (e.g., 43.7% with two siblings), overall, only 30% of patients are able to find an HLA identical match within their family [28]. Indeed, 75% of betathalassemia patients do not have HLA matched siblings [29].…”

SLC25A38 Congenital Sideroblastic Anemia: Phenotypes and genotypes of 31 individuals from 24 families, including 11 novel mutations, and a review of the literature

“…B. An et al, 2019;Andolfo et al, 2020;Fouquet et al, 2019;Guernsey et al, 2009;Kakourou et al, 2016;Kannengiesser et al, 2011;Kim, Shah, Bottomley, & Shah, 2018;Kucerova et al, 2011;Le Rouzic et al, 2017;Liu et al, 2013;Mehri et al, 2018;Ravindra et al, 2020;Shefer Averbuch et al, 2018;Ulirsch et al, 2019;Uminski et al, 2020;Wong et al, 2015). Here we describe the clinical phenotypes and genotypes of an additional 31 individuals from 24 families, including 11 novel mutations.…”

Tek Gen Hastalığı ve HLA Uyumunda Preimplantasyon Genetik Tanı: Tek Merkez Deneyimi

“…Aileye potansiyel YÜT/PGT sınırlamaları, işlem güvenliği, kesinlik ve başarı oranlarını kapsayan ayrıntılı genetik danışma verilmelidir. Her aşamada psikolojik değerlendirme ve destek sağlanmalı, bu süreçte çalışan olan tüm uzmanlar aileyi ayrıntılı olarak bilgilendirmelidir (7,8)…”