Robust preimplantation genetic testing of the common F8 Inv22 pathogenic variant of severe hemophilia A using a highly polymorphic multi-marker panel encompassing the paracentric inversion.
Minh Tam Nguyen, Thanh Tung Nguyen, Duy Bac Nguyen, Thi Mai Nguyen, Kim Ngan Nguyen, Van Nhat Minh Ngo, Van Dieu Nguyen, Ngoc Anh Tran, Mulias Lian, Arnold S C Tan, Samuel S Chong, Tien Truong Dang
{"title":"Robust preimplantation genetic testing of the common F8 Inv22 pathogenic variant of severe hemophilia A using a highly polymorphic multi-marker panel encompassing the paracentric inversion.","authors":"Minh Tam Nguyen, Thanh Tung Nguyen, Duy Bac Nguyen, Thi Mai Nguyen, Kim Ngan Nguyen, Van Nhat Minh Ngo, Van Dieu Nguyen, Ngoc Anh Tran, Mulias Lian, Arnold S C Tan, Samuel S Chong, Tien Truong Dang","doi":"10.1186/s12959-023-00552-w","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Hemophilia A (HEMA) is an X-linked bleeding disorder caused by reduced/absent coagulation factor VIII expression, as a result of pathogenic variants in the F8 gene. Preimplantation prevention of HEMA should ideally include direct pathogenic F8 variant detection, complemented by linkage analysis of flanking markers to identify the high-risk F8 allele. Linkage analysis is particularly indispensable when the pathogenic variant cannot be detected directly or identified. This study evaluated the suitability of a panel of F8 intragenic and extragenic short tandem repeat markers for standalone linkage-based preimplantation genetic testing for monogenic disorder (PGT-M) of the Inv22 pathogenic variant, an almost 600 kb paracentric inversion responsible for almost half of all severe HEMA globally, for which direct detection is challenging.</p><p><strong>Methods: </strong>Thirteen markers spanning 1 Mb and encompassing both F8 and the Inv22 inversion interval were genotyped in 153 unrelated females of Viet Kinh ethnicity.</p><p><strong>Results: </strong>All individuals were heterozygous for ≥ 1 marker, ~ 90% were heterozygous for ≥ 1 of the five F8 intragenic markers, and almost 98% were heterozygous for ≥ 1 upstream (telomeric) and ≥ 1 downstream (centromeric) markers. A prospective PGT-M couple at risk of transmitting F8 Inv22 were fully informative at four marker loci (2 intra-inversion, 1 centromeric, 1 telomeric) and partially informative at another five (2 intra-inversion, 3 centromeric), allowing robust phasing of low- and high-risk haplotypes. In vitro fertilization produced three embryos, all of which clearly inherited the low-risk maternal allele, enabling reliable unaffected diagnoses. A single embryo transfer produced a clinical pregnancy, which was confirmed as unaffected by amniocentesis and long-range PCR, and a healthy baby girl was delivered at term.</p><p><strong>Conclusion: </strong>Robust and reliable PGT-M of HEMA, including the common F8 Inv22 pathogenic variant, can be achieved with sufficient informative intragenic and flanking markers.</p>","PeriodicalId":22982,"journal":{"name":"Thrombosis Journal","volume":null,"pages":null},"PeriodicalIF":2.6000,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10588207/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Thrombosis Journal","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1186/s12959-023-00552-w","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"HEMATOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Hemophilia A (HEMA) is an X-linked bleeding disorder caused by reduced/absent coagulation factor VIII expression, as a result of pathogenic variants in the F8 gene. Preimplantation prevention of HEMA should ideally include direct pathogenic F8 variant detection, complemented by linkage analysis of flanking markers to identify the high-risk F8 allele. Linkage analysis is particularly indispensable when the pathogenic variant cannot be detected directly or identified. This study evaluated the suitability of a panel of F8 intragenic and extragenic short tandem repeat markers for standalone linkage-based preimplantation genetic testing for monogenic disorder (PGT-M) of the Inv22 pathogenic variant, an almost 600 kb paracentric inversion responsible for almost half of all severe HEMA globally, for which direct detection is challenging.
Methods: Thirteen markers spanning 1 Mb and encompassing both F8 and the Inv22 inversion interval were genotyped in 153 unrelated females of Viet Kinh ethnicity.
Results: All individuals were heterozygous for ≥ 1 marker, ~ 90% were heterozygous for ≥ 1 of the five F8 intragenic markers, and almost 98% were heterozygous for ≥ 1 upstream (telomeric) and ≥ 1 downstream (centromeric) markers. A prospective PGT-M couple at risk of transmitting F8 Inv22 were fully informative at four marker loci (2 intra-inversion, 1 centromeric, 1 telomeric) and partially informative at another five (2 intra-inversion, 3 centromeric), allowing robust phasing of low- and high-risk haplotypes. In vitro fertilization produced three embryos, all of which clearly inherited the low-risk maternal allele, enabling reliable unaffected diagnoses. A single embryo transfer produced a clinical pregnancy, which was confirmed as unaffected by amniocentesis and long-range PCR, and a healthy baby girl was delivered at term.
Conclusion: Robust and reliable PGT-M of HEMA, including the common F8 Inv22 pathogenic variant, can be achieved with sufficient informative intragenic and flanking markers.
期刊介绍:
Thrombosis Journal is an open-access journal that publishes original articles on aspects of clinical and basic research, new methodology, case reports and reviews in the areas of thrombosis.
Topics of particular interest include the diagnosis of arterial and venous thrombosis, new antithrombotic treatments, new developments in the understanding, diagnosis and treatments of atherosclerotic vessel disease, relations between haemostasis and vascular disease, hypertension, diabetes, immunology and obesity.