Severe hemophilia A caused by an unbalanced chromosomal rearrangement identified using nanopore sequencing.
F8
chromosome aberrations
duplication
gene fusion
hemophilia A
nanopore sequencing
Journal
Journal of thrombosis and haemostasis : JTH
ISSN: 1538-7836
Titre abrégé: J Thromb Haemost
Pays: England
ID NLM: 101170508
Informations de publication
Date de publication:
07 2019
07 2019
Historique:
received:
14
03
2019
accepted:
18
04
2019
pubmed:
26
4
2019
medline:
15
7
2020
entrez:
26
4
2019
Statut:
ppublish
Résumé
Essentials No F8 genetic abnormality is detected in about 2% of severe hemophilia A patients. Detection of F8 structural variants remains a challenge. We identified a new F8 rearrangement in a severe hemophilia A patient using nanopore sequencing. We highlight the value of single-molecule long-read sequencing technologies in a genomics laboratory. No F8 genetic abnormality is detected in about 2% of severe hemophilia A patients using conventional genetic approaches. In these patients, deep intronic variation or F8 disrupting genomic rearrangement could be causal. To characterize, in a genetically unresolved severe hemophilia A patient, a new Xq28 rearrangement disrupting F8 using comprehensive molecular techniques including nanopore sequencing. Long-range polymerase chain reaction (PCR) performed throughout F8 identified a nonamplifiable region in intron 25 indicating the presence of a genomic rearrangement. F8 messanger ribonucleic acid (mRNA) analysis including 3'rapid amplification of complementary deoxyribonucleic acid (cDNA) ends and nanopore sequencing found the presence of a F8 fusion transcript in which F8 exon 26 was replaced by a 742-bp pseudoexon corresponding to a noncoding region located at the beginning of the long arm of chromosome X (Xq12; chrX: 66 310 352-66 311 093, GRCh37/hg19). Cytogenetic microarray analysis found the presence of a Xq11.1q12 gain of 3.8 Mb. The PCR amplification of junction fragments and fluorescent in situ hybridization (FISH) analysis found that the Xq11q12 duplicated region was inserted in the F8 intron 25 genomic region. We characterized a novel genomic rearrangement in which a 3.8-Mb Xq11.1q12 gain inserted in the F8 intron 25 led to an aberrant fusion transcript in a patient with severe hemophilia A (HA), using comprehensive molecular techniques. This study highlights the value of single-molecule long-read sequencing technologies for molecular diagnosis of HA especially when conventional genetic approaches have failed.
Sections du résumé
Essentials No F8 genetic abnormality is detected in about 2% of severe hemophilia A patients. Detection of F8 structural variants remains a challenge. We identified a new F8 rearrangement in a severe hemophilia A patient using nanopore sequencing. We highlight the value of single-molecule long-read sequencing technologies in a genomics laboratory.
BACKGROUND
No F8 genetic abnormality is detected in about 2% of severe hemophilia A patients using conventional genetic approaches. In these patients, deep intronic variation or F8 disrupting genomic rearrangement could be causal.
OBJECTIVE
To characterize, in a genetically unresolved severe hemophilia A patient, a new Xq28 rearrangement disrupting F8 using comprehensive molecular techniques including nanopore sequencing.
RESULTS
Long-range polymerase chain reaction (PCR) performed throughout F8 identified a nonamplifiable region in intron 25 indicating the presence of a genomic rearrangement. F8 messanger ribonucleic acid (mRNA) analysis including 3'rapid amplification of complementary deoxyribonucleic acid (cDNA) ends and nanopore sequencing found the presence of a F8 fusion transcript in which F8 exon 26 was replaced by a 742-bp pseudoexon corresponding to a noncoding region located at the beginning of the long arm of chromosome X (Xq12; chrX: 66 310 352-66 311 093, GRCh37/hg19). Cytogenetic microarray analysis found the presence of a Xq11.1q12 gain of 3.8 Mb. The PCR amplification of junction fragments and fluorescent in situ hybridization (FISH) analysis found that the Xq11q12 duplicated region was inserted in the F8 intron 25 genomic region.
CONCLUSION
We characterized a novel genomic rearrangement in which a 3.8-Mb Xq11.1q12 gain inserted in the F8 intron 25 led to an aberrant fusion transcript in a patient with severe hemophilia A (HA), using comprehensive molecular techniques. This study highlights the value of single-molecule long-read sequencing technologies for molecular diagnosis of HA especially when conventional genetic approaches have failed.
Identifiants
pubmed: 31021037
doi: 10.1111/jth.14460
pii: S1538-7836(22)14363-1
doi:
Substances chimiques
F8 protein, human
839MOZ74GK
Factor VIII
9001-27-8
Types de publication
Case Reports
Langues
eng
Sous-ensembles de citation
IM
Pagination
1097-1103Informations de copyright
© 2019 International Society on Thrombosis and Haemostasis.