{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T05:09:35Z","timestamp":1778821775905,"version":"3.51.4"},"reference-count":33,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T00:00:00Z","timestamp":1778803200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>\n                      Hemophilia A (HA) is an X-linked recessive bleeding disorder caused by mutations in the\n                      <jats:italic>F8<\/jats:italic>\n                      gene, which exhibits complex molecular mechanisms and high genetic heterogeneity. This study aimed to perform carrier screening and genetic analysis in five phenotypically normal females to identify\n                      <jats:italic>F8<\/jats:italic>\n                      variants and assess their implications for genetic counseling and prenatal diagnosis.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      Genomic DNA was extracted from peripheral blood samples. High-throughput sequencing was used to screen for mutations in 455 genes associated with genetic diseases. Long-range PCR (LR-PCR) was employed to detect the inversion of introns 1 and 22 of the\n                      <jats:italic>F8<\/jats:italic>\n                      gene. Sanger sequencing validated small deletions. To clarify the complex variations of Subject 4, qPCR, CNV-seq and SV-seq analyses were conducted on her affected uncle.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Subject 1 carried an intron 22 inversion (Inv22) of the\n                      <jats:italic>F8<\/jats:italic>\n                      gene. Subjects 2 and 4 carried intron 1 inversions (Inv1). Subject 3 had a small deletion (c.3168_3187del), and Subject 5 had a frameshift deletion (c.4379delA). Notably, Subject 4 was found to carry a rare complex structural variant involving Inv1. QPCR suggested potential duplications in the corresponding genomic region of Subject 4\u2019s uncle. SV-seq identified two duplications on the X chromosome in her uncle, which may disrupt\n                      <jats:italic>F8<\/jats:italic>\n                      gene function.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>\n                      All five subjects carried pathogenic\n                      <jats:italic>F8<\/jats:italic>\n                      gene variants, and one affected individual had a pathogenic variant of the gene. Although carriers are asymptomatic, they can transmit the mutant allele to their offspring. Molecular genetics in carriers is crucial for improving genetic screening, prenatal diagnosis, and the development of targeted therapies for HA. This study further enriches the mutation spectrum of the\n                      <jats:italic>F8<\/jats:italic>\n                      gene and underscores the importance of comprehensively detecting inversions, copy number variations, and structural rearrangements in the molecular diagnosis of hemophilia A.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmed.2026.1805568","type":"journal-article","created":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T04:27:04Z","timestamp":1778819224000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Genetic analysis of F8 mutations in five hemophilia a carriers"],"prefix":"10.3389","volume":"13","author":[{"given":"Huizi","family":"Sun","sequence":"first","affiliation":[{"name":"Department of Central Laboratory, Fujian Key Clinical Specialty of Laboratory Medicine, Department of Obstetrics and Gynecology, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Libin","family":"Mei","sequence":"additional","affiliation":[{"name":"Department of Reproductive Medicine, Department of Obstetrics and Gynecology, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]},{"name":"Xiamen Key Laboratory of Reproduction and Genetics, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xuemei","family":"He","sequence":"additional","affiliation":[{"name":"Department of Reproductive Medicine, Department of Obstetrics and Gynecology, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]},{"name":"Xiamen Key Laboratory of Reproduction and Genetics, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Haijie","family":"Gao","sequence":"additional","affiliation":[{"name":"Department of Reproductive Medicine, Department of Obstetrics and Gynecology, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]},{"name":"Xiamen Key Laboratory of Reproduction and Genetics, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xianjing","family":"Huang","sequence":"additional","affiliation":[{"name":"Department of Reproductive Medicine, Department of Obstetrics and Gynecology, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]},{"name":"Xiamen Key Laboratory of Reproduction and Genetics, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiayan","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Central Laboratory, Fujian Key Clinical Specialty of Laboratory Medicine, Department of Obstetrics and Gynecology, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Meijiao","family":"Cai","sequence":"additional","affiliation":[{"name":"Department of Central Laboratory, Fujian Key Clinical Specialty of Laboratory Medicine, Department of Obstetrics and Gynecology, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ping","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Reproductive Medicine, Department of Obstetrics and Gynecology, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]},{"name":"Xiamen Key Laboratory of Reproduction and Genetics, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yunsheng","family":"Ge","sequence":"additional","affiliation":[{"name":"Department of Central Laboratory, Fujian Key Clinical Specialty of Laboratory Medicine, Department of Obstetrics and Gynecology, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanru","family":"Huang","sequence":"additional","affiliation":[{"name":"Department of Central Laboratory, Fujian Key Clinical Specialty of Laboratory Medicine, Department of Obstetrics and Gynecology, Women and Children's Hospital, School of Medicine, Xiamen University","place":["Xiamen, Fujian, China"]},{"name":"School of Public Health, Xiamen University","place":["Xiamen, Fujian, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,5,15]]},"reference":[{"key":"ref1","doi-asserted-by":"crossref","first-page":"3983","DOI":"10.1182\/blood.V92.11.3983","article-title":"The life cycle of coagulation factor VIII in view of its structure and function","volume":"92","author":"Lenting","year":"1998","journal-title":"Blood"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"1447","DOI":"10.1016\/S0140-6736(11)61139-2","article-title":"Modern haemophilia care","volume":"379","author":"Berntorp","year":"2012","journal-title":"Lancet"},{"key":"ref3","doi-asserted-by":"crossref","first-page":"560","DOI":"10.1055\/s-0037-1615621","article-title":"Definitions in hemophilia. Recommendation of the scientific subcommittee on factor VIII and factor IX of the scientific and standardization committee of the international society on thrombosis and Haemostasis","volume":"85","author":"White","year":"2001","journal-title":"Thromb Haemost"},{"key":"ref4","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1038\/ng1193-236","article-title":"Inversions disrupting the factor VIII gene are a common cause of severe haemophilia a","volume":"5","author":"Lakich","year":"1993","journal-title":"Nat Genet"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"1183","DOI":"10.1002\/pd.2393","article-title":"Inverse shifting PCR based prenatal diagnosis of hemophilia-causative inversions involving int22h and int1h hotspots from chorionic villus samples","volume":"29","author":"Radic","year":"2009","journal-title":"Prenat Diagn"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"168","DOI":"10.1182\/blood.V99.1.168","article-title":"Recurrent inversion breaking intron 1 of the factor VIII gene is a frequent cause of severe hemophilia a","volume":"99","author":"Bagnall","year":"2002","journal-title":"Blood"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"1098795","DOI":"10.3389\/fgene.2023.1098795","article-title":"F8 gene inversion and duplication cause no obvious hemophilia a phenotype","volume":"14","author":"Li","year":"2023","journal-title":"Front Genet"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"541","DOI":"10.1111\/j.1365-2516.2010.02444.x","article-title":"Prevalence of the factor 8 gene intron 1 inversion in Chinese haemophiliacs and its application to carrier detection and prenatal diagnosis in haemophilia a families","volume":"17","author":"Lu","year":"2011","journal-title":"Haemophilia"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/j.critrevonc.2016.04.005","article-title":"Principles of genetic variations and molecular diseases: applications in hemophilia a","volume":"104","author":"Lannoy","year":"2016","journal-title":"Crit Rev Oncol Hematol"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"519","DOI":"10.1016\/j.jmoldx.2014.05.002","article-title":"Copy number variation sequencing for comprehensive diagnosis of chromosome disease syndromes","volume":"16","author":"Liang","year":"2014","journal-title":"J Mol Diagn"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"3228","DOI":"10.1093\/bioinformatics\/btr563","article-title":"SVseq: an approach for detecting exact breakpoints of deletions with low-coverage sequence data","volume":"27","author":"Zhang","year":"2011","journal-title":"Bioinformatics"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"124","DOI":"10.1016\/j.bcmd.2009.11.006","article-title":"Prenatal diagnosis of hemophilia a, presenting a new mutation in the FVIII gene","volume":"44","author":"He","year":"2010","journal-title":"Blood Cells Mol Dis"},{"key":"ref13","doi-asserted-by":"publisher","first-page":"23","DOI":"10.18388\/abp.2018_2339","article-title":"Identification of six novel factor viii gene variants using next generation sequencing and molecular dynamics simulation","volume":"66","author":"Al-Allaf","year":"2019","journal-title":"Acta Biochim Pol"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"e97337","DOI":"10.1371\/journal.pone.0097337","article-title":"Mutations in intron 1 and intron 22 inversion negative haemophilia a patients from Western India","volume":"9","author":"Nair","year":"2014","journal-title":"PLoS One"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"711","DOI":"10.1111\/hae.13569","article-title":"Review of molecular mechanisms at distal Xq28 leading to balanced or unbalanced genomic rearrangements and their phenotypic impacts on hemophilia","volume":"24","author":"Lannoy","year":"2018","journal-title":"Haemophilia"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"e0151800","DOI":"10.1371\/journal.pone.0151800","article-title":"Successful phenotype improvement following gene therapy for severe hemophilia a in privately owned dogs","volume":"11","author":"Callan","year":"2016","journal-title":"PLoS One"},{"key":"ref17","doi-asserted-by":"publisher","first-page":"503","DOI":"10.1159\/000539099","article-title":"Two-compound heterozygous deletions affecting TUBGCP6 in a patient with microcephaly and ocular abnormalities and in an unborn sibling with abnormal Sulcation","volume":"15","author":"Pal","year":"2024","journal-title":"Mol Syndromol"},{"key":"ref18","doi-asserted-by":"crossref","first-page":"2206","DOI":"10.1182\/blood.V86.6.2206.bloodjournal8662206","article-title":"Factor VIII gene inversions in severe hemophilia a: results of an international consortium study","volume":"86","author":"Antonarakis","year":"1995","journal-title":"Blood"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"450","DOI":"10.1515\/CCLM.2007.093","article-title":"Haemophilia a: molecular insights","volume":"45","author":"Castaldo","year":"2007","journal-title":"Clin Chem Lab Med"},{"key":"ref20","doi-asserted-by":"publisher","first-page":"e88","DOI":"10.1111\/hae.14206","article-title":"Mutation analysis in the F8 gene in 485 families with haemophilia a and prenatal diagnosis in China","volume":"27","author":"Feng","year":"2021","journal-title":"Haemophilia"},{"key":"ref21","doi-asserted-by":"publisher","first-page":"1041","DOI":"10.3390\/life14081041","article-title":"Comprehensive screening of genetic variants in the coding region of F8 in severe hemophilia a reveals a relationship with disease severity in a Colombian cohort","volume":"14","author":"Sarmiento Doncel","year":"2024","journal-title":"Life (Basel)"},{"key":"ref22","doi-asserted-by":"publisher","first-page":"e1001111","DOI":"10.1371\/journal.pgen.1001111","article-title":"The characterization of twenty sequenced human genomes","volume":"6","author":"Pelak","year":"2010","journal-title":"PLoS Genet"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"824","DOI":"10.1182\/bloodadvances.2016002923","article-title":"Novel approach to genetic analysis and results in 3000 hemophilia patients enrolled in the my life, our future initiative","volume":"1","author":"Johnsen","year":"2017","journal-title":"Blood Adv"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"1756","DOI":"10.1111\/j.1538-7836.2006.02055.x","article-title":"DNA microarray analysis for the detection of mutations in hemophilia a","volume":"4","author":"Berber","year":"2006","journal-title":"J Thromb Haemost"},{"key":"ref25","doi-asserted-by":"crossref","first-page":"S69","DOI":"10.1055\/s-0037-1619754","article-title":"Unusual genomic rearrangements in introns 1 and 22 of the F8 gene","volume":"31","author":"Zimmermann","year":"2011","journal-title":"Hamostaseologie"},{"key":"ref26","doi-asserted-by":"publisher","first-page":"718","DOI":"10.1016\/j.ajhg.2011.04.017","article-title":"Loss of BRCC3 deubiquitinating enzyme leads to abnormal angiogenesis and is associated with syndromic moyamoya","volume":"88","author":"Miskinyte","year":"2011","journal-title":"Am J Hum Genet"},{"key":"ref27","doi-asserted-by":"publisher","first-page":"195","DOI":"10.1111\/jth.12061","article-title":"Aberrant F8 gene intron 1 inversion with concomitant duplication and deletion in a severe hemophilia a patient from southern Italy","volume":"11","author":"Sanna","year":"2013","journal-title":"J Thromb Haemost"},{"key":"ref28","doi-asserted-by":"publisher","first-page":"264","DOI":"10.1160\/TH13-10-0892","article-title":"Identification and characterisation of a novel aberrant pattern of intron 1 inversion with concomitant large insertion and deletion within the F8 gene","volume":"112","author":"You","year":"2014","journal-title":"Thromb Haemost"},{"key":"ref29","doi-asserted-by":"publisher","first-page":"53","DOI":"10.1080\/16078454.2020.1867793","article-title":"An aberrant F8 intron 1 inversion with concomitant large duplication and deletion in a Chinese severe hemophilia a patient","volume":"26","author":"Wang","year":"2021","journal-title":"Hematology"},{"key":"ref30","doi-asserted-by":"publisher","first-page":"1098","DOI":"10.3390\/diagnostics12051098","article-title":"Experience of low-pass whole-genome sequencing-based copy number variant analysis: a survey of Chinese tertiary hospitals","volume":"12","author":"Zheng","year":"2022","journal-title":"Diagnostics (Basel)"},{"key":"ref31","doi-asserted-by":"publisher","first-page":"363","DOI":"10.1007\/s00439-022-02510-4","article-title":"Mate-pair genome sequencing reveals structural variants for idiopathic male infertility","volume":"142","author":"Dong","year":"2023","journal-title":"Hum Genet"},{"key":"ref32","doi-asserted-by":"publisher","first-page":"15","DOI":"10.1186\/s12958-020-00572-5","article-title":"Successful pregnancy after prenatal diagnosis by NGS for a carrier of complex chromosome rearrangements","volume":"18","author":"Ou","year":"2020","journal-title":"Reprod Biol Endocrinol"},{"key":"ref33","doi-asserted-by":"publisher","first-page":"155","DOI":"10.1186\/s13052-025-01987-9","article-title":"SVseq discloses the genomic complexity of different prenatal, de novo, apparently balanced chromosome rearrangements detected by CMA and karyotype","volume":"51","author":"Qin","year":"2025","journal-title":"Ital J Pediatr"}],"container-title":["Frontiers in Medicine"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmed.2026.1805568\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T04:27:05Z","timestamp":1778819225000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmed.2026.1805568\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,15]]},"references-count":33,"alternative-id":["10.3389\/fmed.2026.1805568"],"URL":"https:\/\/doi.org\/10.3389\/fmed.2026.1805568","relation":{},"ISSN":["2296-858X"],"issn-type":[{"value":"2296-858X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,15]]},"article-number":"1805568"}}