Deep Intronic Variant c.5999-277G>A of F8 Gene May Be a Hot-Spot Mutation for Mild Hemophilia A Patients Without Mutation in Exonic DNA

Chia-Yau Chang, Cherng-Lih Perng, Shin-Nan Cheng, Shu-Hsia Hu, Tzu-Ying Wu, Shyr-Yi Lin, Yeu-Chin Chen

Research output: Contribution to journalArticle

Abstract

BACKGROUND: In 10-18% of mild type Hemophilia A (HA) patients, mutations cannot be found by routine DNA analysis.

OBJECTIVE: We aimed to identify the genetic defects by mRNA analysis of F8 gene in mild HA patients without mutation in exonic DNA.

PATIENTS AND METHODS: From 2006 to 2016, we identified F8 exon mutations in 39 of 49 mild HA patients using routine genetic testing. We then evaluated the 10 remaining patients from 6 unrelated families without exonic DNA mutation by performing cDNA sequence analysis.

RESULTS: Nine of the 10 (90%) patients were confirmed to have F8 gene mutation. Eight patients from 4 unrelated families were notably found to have presence of an aberrant 675 bp fragment. Sequencing of this fragment showed that there were two separate new alternative splicing exons of 35 bp and 55 bp within intron 18, which formed a 90-bp insertion between exon 18 and exon 19 (E18ins90bpE19) in the mRNA. Based on direct sequencing, this alternative splicing transcript appears to have resulted from deep intronic variant c.5999-277G>A of intron 18.

CONCLUSIONS: Our study suggests that deep intronic variant of c.5999-277G>A may be a hot-spot mutation for mild hemophilia patients without mutation in exonic DNA. This article is protected by copyright. All rights reserved.

Original languageEnglish
JournalEuropean Journal of Haematology
DOIs
Publication statusE-pub ahead of print - May 7 2019

Fingerprint

Hemophilia A
Mutation
DNA
Exons
Genes
Alternative Splicing
Introns
Messenger RNA
Genetic Testing
Sequence Analysis
Complementary DNA

Cite this

Deep Intronic Variant c.5999-277G>A of F8 Gene May Be a Hot-Spot Mutation for Mild Hemophilia A Patients Without Mutation in Exonic DNA. / Chang, Chia-Yau; Perng, Cherng-Lih; Cheng, Shin-Nan; Hu, Shu-Hsia; Wu, Tzu-Ying; Lin, Shyr-Yi; Chen, Yeu-Chin.

In: European Journal of Haematology, 07.05.2019.

Research output: Contribution to journalArticle

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title = "Deep Intronic Variant c.5999-277G>A of F8 Gene May Be a Hot-Spot Mutation for Mild Hemophilia A Patients Without Mutation in Exonic DNA",
abstract = "BACKGROUND: In 10-18{\%} of mild type Hemophilia A (HA) patients, mutations cannot be found by routine DNA analysis.OBJECTIVE: We aimed to identify the genetic defects by mRNA analysis of F8 gene in mild HA patients without mutation in exonic DNA.PATIENTS AND METHODS: From 2006 to 2016, we identified F8 exon mutations in 39 of 49 mild HA patients using routine genetic testing. We then evaluated the 10 remaining patients from 6 unrelated families without exonic DNA mutation by performing cDNA sequence analysis.RESULTS: Nine of the 10 (90{\%}) patients were confirmed to have F8 gene mutation. Eight patients from 4 unrelated families were notably found to have presence of an aberrant 675 bp fragment. Sequencing of this fragment showed that there were two separate new alternative splicing exons of 35 bp and 55 bp within intron 18, which formed a 90-bp insertion between exon 18 and exon 19 (E18ins90bpE19) in the mRNA. Based on direct sequencing, this alternative splicing transcript appears to have resulted from deep intronic variant c.5999-277G>A of intron 18.CONCLUSIONS: Our study suggests that deep intronic variant of c.5999-277G>A may be a hot-spot mutation for mild hemophilia patients without mutation in exonic DNA. This article is protected by copyright. All rights reserved.",
author = "Chia-Yau Chang and Cherng-Lih Perng and Shin-Nan Cheng and Shu-Hsia Hu and Tzu-Ying Wu and Shyr-Yi Lin and Yeu-Chin Chen",
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year = "2019",
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doi = "10.1111/ejh.13242",
language = "English",
journal = "European Journal of Haematology",
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T1 - Deep Intronic Variant c.5999-277G>A of F8 Gene May Be a Hot-Spot Mutation for Mild Hemophilia A Patients Without Mutation in Exonic DNA

AU - Chang, Chia-Yau

AU - Perng, Cherng-Lih

AU - Cheng, Shin-Nan

AU - Hu, Shu-Hsia

AU - Wu, Tzu-Ying

AU - Lin, Shyr-Yi

AU - Chen, Yeu-Chin

N1 - This article is protected by copyright. All rights reserved.

PY - 2019/5/7

Y1 - 2019/5/7

N2 - BACKGROUND: In 10-18% of mild type Hemophilia A (HA) patients, mutations cannot be found by routine DNA analysis.OBJECTIVE: We aimed to identify the genetic defects by mRNA analysis of F8 gene in mild HA patients without mutation in exonic DNA.PATIENTS AND METHODS: From 2006 to 2016, we identified F8 exon mutations in 39 of 49 mild HA patients using routine genetic testing. We then evaluated the 10 remaining patients from 6 unrelated families without exonic DNA mutation by performing cDNA sequence analysis.RESULTS: Nine of the 10 (90%) patients were confirmed to have F8 gene mutation. Eight patients from 4 unrelated families were notably found to have presence of an aberrant 675 bp fragment. Sequencing of this fragment showed that there were two separate new alternative splicing exons of 35 bp and 55 bp within intron 18, which formed a 90-bp insertion between exon 18 and exon 19 (E18ins90bpE19) in the mRNA. Based on direct sequencing, this alternative splicing transcript appears to have resulted from deep intronic variant c.5999-277G>A of intron 18.CONCLUSIONS: Our study suggests that deep intronic variant of c.5999-277G>A may be a hot-spot mutation for mild hemophilia patients without mutation in exonic DNA. This article is protected by copyright. All rights reserved.

AB - BACKGROUND: In 10-18% of mild type Hemophilia A (HA) patients, mutations cannot be found by routine DNA analysis.OBJECTIVE: We aimed to identify the genetic defects by mRNA analysis of F8 gene in mild HA patients without mutation in exonic DNA.PATIENTS AND METHODS: From 2006 to 2016, we identified F8 exon mutations in 39 of 49 mild HA patients using routine genetic testing. We then evaluated the 10 remaining patients from 6 unrelated families without exonic DNA mutation by performing cDNA sequence analysis.RESULTS: Nine of the 10 (90%) patients were confirmed to have F8 gene mutation. Eight patients from 4 unrelated families were notably found to have presence of an aberrant 675 bp fragment. Sequencing of this fragment showed that there were two separate new alternative splicing exons of 35 bp and 55 bp within intron 18, which formed a 90-bp insertion between exon 18 and exon 19 (E18ins90bpE19) in the mRNA. Based on direct sequencing, this alternative splicing transcript appears to have resulted from deep intronic variant c.5999-277G>A of intron 18.CONCLUSIONS: Our study suggests that deep intronic variant of c.5999-277G>A may be a hot-spot mutation for mild hemophilia patients without mutation in exonic DNA. This article is protected by copyright. All rights reserved.

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DO - 10.1111/ejh.13242

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JO - European Journal of Haematology

JF - European Journal of Haematology

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