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Genetics of brain arteriovenous malformations and cerebral cavernous malformations. J Hum Genet 2023; 68:157-167. [PMID: 35831630 DOI: 10.1038/s10038-022-01063-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/13/2022] [Accepted: 06/26/2022] [Indexed: 11/08/2022]
Abstract
Cerebrovascular malformations comprise abnormal development of cerebral vasculature. They can result in hemorrhagic stroke due to rupture of lesions as well as seizures and neurological defects. The most common forms of cerebrovascular malformations are brain arteriovenous malformations (bAVMs) and cerebral cavernous malformations (CCMs). They occur in both sporadic and inherited forms. Rapidly evolving molecular genetic methodologies have helped to identify causative or associated genes involved in genesis of bAVMs and CCMs. In this review, we highlight the current knowledge regarding the genetic basis of these malformations.
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Skowronek D, Pilz RA, Bonde L, Schamuhn OJ, Feldmann JL, Hoffjan S, Much CD, Felbor U, Rath M. Cas9-Mediated Nanopore Sequencing Enables Precise Characterization of Structural Variants in CCM Genes. Int J Mol Sci 2022; 23:ijms232415639. [PMID: 36555281 PMCID: PMC9779250 DOI: 10.3390/ijms232415639] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/05/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
Deletions in the CCM1, CCM2, and CCM3 genes are a common cause of familial cerebral cavernous malformations (CCMs). In current molecular genetic laboratories, targeted next-generation sequencing or multiplex ligation-dependent probe amplification are mostly used to identify copy number variants (CNVs). However, both techniques are limited in their ability to specify the breakpoints of CNVs and identify complex structural variants (SVs). To overcome these constraints, we established a targeted Cas9-mediated nanopore sequencing approach for CNV detection with single nucleotide resolution. Using a MinION device, we achieved complete coverage for the CCM genes and determined the exact size of CNVs in positive controls. Long-read sequencing for a CCM1 and CCM2 CNV revealed that the adjacent ANKIB1 and NACAD genes were also partially or completely deleted. In addition, an interchromosomal insertion and an inversion in CCM2 were reliably re-identified by long-read sequencing. The refinement of CNV breakpoints by long-read sequencing enabled fast and inexpensive PCR-based variant confirmation, which is highly desirable to reduce costs in subsequent family analyses. In conclusion, Cas9-mediated nanopore sequencing is a cost-effective and flexible tool for molecular genetic diagnostics which can be easily adapted to various target regions.
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Affiliation(s)
- Dariush Skowronek
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, 17475 Greifswald, Germany
| | - Robin A. Pilz
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, 17475 Greifswald, Germany
| | - Loisa Bonde
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, 17475 Greifswald, Germany
| | - Ole J. Schamuhn
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, 17475 Greifswald, Germany
| | - Janne L. Feldmann
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, 17475 Greifswald, Germany
| | - Sabine Hoffjan
- Department of Human Genetics, Ruhr-University, 44801 Bochum, Germany
| | - Christiane D. Much
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, 17475 Greifswald, Germany
| | - Ute Felbor
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, 17475 Greifswald, Germany
| | - Matthias Rath
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, 17475 Greifswald, Germany
- Department of Human Medicine and Institute for Molecular Medicine, MSH Medical School Hamburg, 20457 Hamburg, Germany
- Correspondence:
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Keegan NP, Wilton SD, Fletcher S. Analysis of Pathogenic Pseudoexons Reveals Novel Mechanisms Driving Cryptic Splicing. Front Genet 2022; 12:806946. [PMID: 35140743 PMCID: PMC8819188 DOI: 10.3389/fgene.2021.806946] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/09/2021] [Indexed: 12/16/2022] Open
Abstract
Understanding pre-mRNA splicing is crucial to accurately diagnosing and treating genetic diseases. However, mutations that alter splicing can exert highly diverse effects. Of all the known types of splicing mutations, perhaps the rarest and most difficult to predict are those that activate pseudoexons, sometimes also called cryptic exons. Unlike other splicing mutations that either destroy or redirect existing splice events, pseudoexon mutations appear to create entirely new exons within introns. Since exon definition in vertebrates requires coordinated arrangements of numerous RNA motifs, one might expect that pseudoexons would only arise when rearrangements of intronic DNA create novel exons by chance. Surprisingly, although such mutations do occur, a far more common cause of pseudoexons is deep-intronic single nucleotide variants, raising the question of why these latent exon-like tracts near the mutation sites have not already been purged from the genome by the evolutionary advantage of more efficient splicing. Possible answers may lie in deep intronic splicing processes such as recursive splicing or poison exon splicing. Because these processes utilize intronic motifs that benignly engage with the spliceosome, the regions involved may be more susceptible to exonization than other intronic regions would be. We speculated that a comprehensive study of reported pseudoexons might detect alignments with known deep intronic splice sites and could also permit the characterisation of novel pseudoexon categories. In this report, we present and analyse a catalogue of over 400 published pseudoexon splice events. In addition to confirming prior observations of the most common pseudoexon mutation types, the size of this catalogue also enabled us to suggest new categories for some of the rarer types of pseudoexon mutation. By comparing our catalogue against published datasets of non-canonical splice events, we also found that 15.7% of pseudoexons exhibit some splicing activity at one or both of their splice sites in non-mutant cells. Importantly, this included seven examples of experimentally confirmed recursive splice sites, confirming for the first time a long-suspected link between these two splicing phenomena. These findings have the potential to improve the fidelity of genetic diagnostics and reveal new targets for splice-modulating therapies.
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Affiliation(s)
- Niall P. Keegan
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
- *Correspondence: Niall P. Keegan,
| | - Steve D. Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
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Ajiro M, Awaya T, Kim YJ, Iida K, Denawa M, Tanaka N, Kurosawa R, Matsushima S, Shibata S, Sakamoto T, Studer R, Krainer AR, Hagiwara M. Therapeutic manipulation of IKBKAP mis-splicing with a small molecule to cure familial dysautonomia. Nat Commun 2021; 12:4507. [PMID: 34301951 PMCID: PMC8302731 DOI: 10.1038/s41467-021-24705-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 06/21/2021] [Indexed: 01/10/2023] Open
Abstract
Approximately half of genetic disease-associated mutations cause aberrant splicing. However, a widely applicable therapeutic strategy to splicing diseases is yet to be developed. Here, we analyze the mechanism whereby IKBKAP-familial dysautonomia (FD) exon 20 inclusion is specifically promoted by a small molecule splice modulator, RECTAS, even though IKBKAP-FD exon 20 has a suboptimal 5' splice site due to the IVS20 + 6 T > C mutation. Knockdown experiments reveal that exon 20 inclusion is suppressed in the absence of serine/arginine-rich splicing factor 6 (SRSF6) binding to an intronic splicing enhancer in intron 20. We show that RECTAS directly interacts with CDC-like kinases (CLKs) and enhances SRSF6 phosphorylation. Consistently, exon 20 splicing is bidirectionally manipulated by targeting cellular CLK activity with RECTAS versus CLK inhibitors. The therapeutic potential of RECTAS is validated in multiple FD disease models. Our study indicates that small synthetic molecules affecting phosphorylation state of SRSFs is available as a new therapeutic modality for mechanism-oriented precision medicine of splicing diseases.
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Affiliation(s)
- Masahiko Ajiro
- Department of Drug Discovery Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tomonari Awaya
- Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Young Jin Kim
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Kei Iida
- Medical Research Support Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Masatsugu Denawa
- Medical Research Support Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Nobuo Tanaka
- Medical Research Support Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Ryo Kurosawa
- Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Shingo Matsushima
- Department of Drug Discovery Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Saiko Shibata
- Department of Drug Discovery Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tetsunori Sakamoto
- Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Rolenz Studer
- Center for Stem Cell Biology, Sloan Kettering Institute, New York, NY, USA
| | | | - Masatoshi Hagiwara
- Department of Drug Discovery Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan. .,Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
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Shibata S, Ajiro M, Hagiwara M. Mechanism-Based Personalized Medicine for Cystic Fibrosis by Suppressing Pseudo Exon Inclusion. Cell Chem Biol 2020; 27:1472-1482.e6. [DOI: 10.1016/j.chembiol.2020.08.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/29/2020] [Accepted: 08/20/2020] [Indexed: 12/14/2022]
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First interchromosomal insertion in a patient with cerebral and spinal cavernous malformations. Sci Rep 2020; 10:6306. [PMID: 32286434 PMCID: PMC7156631 DOI: 10.1038/s41598-020-63337-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 03/30/2020] [Indexed: 01/06/2023] Open
Abstract
Autosomal dominant cerebral cavernous malformations (CCM) are leaky vascular lesions that can cause epileptic seizures and stroke-like symptoms. Germline mutations in either CCM1, CCM2 or CCM3 are found in the majority of patients with multiple CCMs or a positive family history. Recently, the first copy number neutral inversion in CCM2 has been identified by whole genome sequencing in an apparently mutation-negative CCM family. We here asked the question whether further structural genomic rearrangements can be detected within NGS gene panel data of unsolved CCM cases. Hybrid capture NGS data of eight index patients without a pathogenic single nucleotide, indel or copy number variant were analyzed using two bioinformatics pipelines. In a 58-year-old male with multiple CCMs in his brain and spinal cord, we identified a 294 kb insertion within the coding sequence of CCM2. Fine mapping of the breakpoints, molecular cytogenetic studies, and multiplex ligation-dependent probe amplification verified that the structural variation was an inverted unbalanced insertion that originated from 1p12-p11.2. As this rearrangement disrupts exon 6 of CCM2 on 7p13, it was classified as pathogenic. Our study demonstrates that efforts to detect structural variations in known disease genes increase the diagnostic sensitivity of genetic analyses for well-defined Mendelian disorders.
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Understanding human DNA variants affecting pre-mRNA splicing in the NGS era. ADVANCES IN GENETICS 2019; 103:39-90. [PMID: 30904096 DOI: 10.1016/bs.adgen.2018.09.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Pre-mRNA splicing, an essential step in eukaryotic gene expression, relies on recognition of short sequences on the primary transcript intron ends and takes place along transcription by RNA polymerase II. Exonic and intronic auxiliary elements may modify the strength of exon definition and intron recognition. Splicing DNA variants (SV) have been associated with human genetic diseases at canonical intron sites, as well as exonic substitutions putatively classified as nonsense, missense or synonymous variants. Their effects on mRNA may be modulated by cryptic splice sites associated to the SV allele, comprehending exon skipping or shortening, and partial or complete intron retention. As splicing mRNA outputs result from combinatorial effects of both intrinsic and extrinsic factors, in vitro functional assays supported by computational analyses are recommended to assist SV pathogenicity assessment for human Mendelian inheritance diseases. The increasing use of next-generating sequencing (NGS) targeting full genomic gene sequence has raised awareness of the relevance of deep intronic SV in genetic diseases and inclusion of pseudo-exons into mRNA. Finally, we take advantage of recent advances in sequencing and computational technologies to analyze alternative splicing in cancer. We explore the Catalog of Somatic Mutations in Cancer (COSMIC) to describe the proportion of splice-site mutations in cis and trans regulatory elements. Genomic data from large cohorts of different cancer types are increasingly available, in addition to repositories of normal and somatic genetic variations. These are likely to bring new insights to understanding the genetic control of alternative splicing by mapping splicing quantitative trait loci in tumors.
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Spiegler S, Rath M, Paperlein C, Felbor U. Cerebral Cavernous Malformations: An Update on Prevalence, Molecular Genetic Analyses, and Genetic Counselling. Mol Syndromol 2018; 9:60-69. [PMID: 29593473 PMCID: PMC5836221 DOI: 10.1159/000486292] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2017] [Indexed: 11/19/2022] Open
Abstract
Based on the latest gnomAD dataset, the prevalence of symptomatic hereditary cerebral cavernous malformations (CCMs) prone to cause epileptic seizures and stroke-like symptoms was re-evaluated in this review and calculated to be 1:5,400-1:6,200. Furthermore, state-of-the-art molecular genetic analyses of the known CCM loci are described which reach an almost 100% mutation detection rate for familial CCMs if whole genome sequencing is performed for seemingly mutation-negative families. An update on the spectrum of CCM1, CCM2, and CCM3 mutations demonstrates that deep-intronic mutations and submicroscopic copy-number neutral genomic rearrangements are rare. Finally, this review points to current guidelines on genetic counselling, neuroimaging, medical as well as neurosurgical treatment and highlights the formation of active patient organizations in various countries.
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Affiliation(s)
- Stefanie Spiegler
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald
| | - Matthias Rath
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald
| | - Christin Paperlein
- Institute of Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Greifswald, Germany
| | - Ute Felbor
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald
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Al-Sharydah AM, Al-Suhibani SS, Al-Jubran SA, Al-Abdulwahhab AH, Al-Bar M, Al-Jehani HM, Al-Issawi WM. Endoscopic management of Atypical sellar cavernous hemangioma: A case report and review of the literature. Int J Surg Case Rep 2017; 42:161-164. [PMID: 29248833 PMCID: PMC5985255 DOI: 10.1016/j.ijscr.2017.12.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 11/29/2017] [Accepted: 12/02/2017] [Indexed: 11/24/2022] Open
Abstract
INTRODUCTION supratentorial cavernous hemangiomas, particularly those found in the sellar region, are extremely rare. We present a case of sellar cavernous hemangioma with radiological characteristics that have never been reported. Due to the difficulty diagnosing these lesions, misdiagnosis might occur. Thus, briefing surgeons about the clinico-radiological features of such rare lesions is crucial for better understanding the enigmatic features of such rare lesions and to develop early management approaches that could result in better surgical excision with a lower tendency for complications. PRESENTATION OF CASE A 43-year-old male presented with headache, blurred vision, and impotence for the last 2 years. Brain magnetic resonance imaging showed an atypical sellar mass displaying signals of heterogeneous intensity on T1- and T2-weighted imaging. The mass exhibited heterogeneous enhancement after gadolinium injection. Endoscopic endonasal surgery was subsequently performed, during which an uneventful subtotal resection of the mass was achieved. Histopathological analysis confirmed the diagnosis of intrasellar cavernous hemangioma. DISCUSSION Many questions regarding how best to manage such lesions remain unanswered. Hence, we summarize the relevant surgical techniques and discuss misconceptions. CONCLUSION Seller cavernous hemangioma (SCH) is an extremely rare lesion that can be misdiagnosed. It is characterized by clinico-radiological features similar to those of other lesions such as pituitary macroadenoma and should be included in the differential diagnosis. The endoscopic endonasal transsphenoidal (EET) approach with subtotal/total resection appears to be a feasible option for debulking, with less surgical complications. Nonetheless, combining stereotactic radiosurgery will reduce postsurgical morbidities.
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Affiliation(s)
- A M Al-Sharydah
- Radiology Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Saudi Arabia
| | - S S Al-Suhibani
- Radiology Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Saudi Arabia.
| | - S A Al-Jubran
- Radiology Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Saudi Arabia.
| | - A H Al-Abdulwahhab
- Radiology Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Saudi Arabia.
| | - M Al-Bar
- Otolaryngology Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Saudi Arabia.
| | - H M Al-Jehani
- Neurosurgery Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Saudi Arabia.
| | - W M Al-Issawi
- Neurosurgery Department, Imam Abdulrahman Bin Faisal University, King Fahd Hospital of the University, Saudi Arabia.
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Mondejar R, Lucas M. Molecular diagnosis in cerebral cavernous malformations. NEUROLOGÍA (ENGLISH EDITION) 2017. [DOI: 10.1016/j.nrleng.2015.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Rath M, Jenssen SE, Schwefel K, Spiegler S, Kleimeier D, Sperling C, Kaderali L, Felbor U. High-throughput sequencing of the entire genomic regions of CCM1/KRIT1 , CCM2 and CCM3/PDCD10 to search for pathogenic deep-intronic splice mutations in cerebral cavernous malformations. Eur J Med Genet 2017. [DOI: 10.1016/j.ejmg.2017.06.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Mukai S, Nagata K, Ikeda M, Arai S, Sugano M, Honda T, Okumura N. Genetic analyses of novel compound heterozygous hypodysfibrinogenemia, Tsukuba I: FGG c.1129+62_65 del AATA and FGG c.1299+4 del A. Thromb Res 2016; 148:111-117. [PMID: 27837696 DOI: 10.1016/j.thromres.2016.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 10/24/2016] [Accepted: 11/03/2016] [Indexed: 12/01/2022]
Abstract
INTRODUCTION We found a novel hypodysfibrinogenemia designated Tsukuba I caused by compound heterozygous nucleotide deletions with FGG c.1129+62_65 del AATA and FGG c.1299+4 del A on different alleles. The former was deep in intron 8 of FGG (IVS-8 deletion) and the latter in exon 9 of FGG (Ex-9 deletion), which is translated for the γ'-chain, but not the γA-chain. A Western blot analysis of plasma fibrinogen from our patient revealed an aberrant γ-chain that migrated slightly faster than the normal Bβ-chain. MATERIALS AND METHODS To clarify the complex genetic mechanism underlying Tsukuba I's hypodysfibrinogenemia induced by nucleotide deletions in two regions, we generated two minigenes incorporating each deletion region, transfected them into Chinese Hamster Ovary (CHO) cells, and analyzed RT-PCR products. We also established CHO cells producing the recombinant variant fibrinogen, γ'409ΔA (Ex-9 deletion). RESULTS AND CONCLUSIONS Minigene I incorporating the IVS-8 deletion showed two products: a normal splicing product and the unspliced product. Minigene II incorporating the Ex-9 deletion only produced the unspliced product. The established γ'409ΔA-CHO cells secreted variant fibrinogen more effectively than normal fibrinogen. Therefore, the aberrant splicing products derived from the IVS-8 deletion cause hypofibrinogenemia most likely due to nonsense-mediated mRNA decay and the partial production of normal γA- and γ'-chains; moreover, the Ex-9 deletion causes hypodysfibrinogenemia due to the absence of normal γA- and γ'-chain production (hypofibrinogenemia) and augmented aberrant γ'-chain production (dysfibrinogenemia).
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Affiliation(s)
- Saki Mukai
- Department of Health and Medical Sciences, Graduate School of Medicine, Shinshu University, Matsumoto, Japan; Department of Laboratory Medicine, Shinshu University Hospital, Matsumoto, Japan
| | - Kazuhiro Nagata
- Department of Health and Medical Sciences, Graduate School of Medicine, Shinshu University, Matsumoto, Japan; Department of Laboratory Medicine, Shinshu University Hospital, Matsumoto, Japan
| | - Minami Ikeda
- Department of Laboratory Medicine, Shinshu University Hospital, Matsumoto, Japan
| | - Shinpei Arai
- Department of Laboratory Medicine, Shinshu University Hospital, Matsumoto, Japan; Department of Laboratory Medicine, Graduate School of Medicine, Shinshu University, Matsumoto, Japan
| | - Mitsutoshi Sugano
- Department of Laboratory Medicine, Shinshu University Hospital, Matsumoto, Japan
| | - Takayuki Honda
- Department of Laboratory Medicine, Graduate School of Medicine, Shinshu University, Matsumoto, Japan
| | - Nobuo Okumura
- Department of Health and Medical Sciences, Graduate School of Medicine, Shinshu University, Matsumoto, Japan.
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Analysis of CCM1 expression uncovers novel minor-form exons and variable splicing patterns. Genes Genomics 2016. [DOI: 10.1007/s13258-016-0435-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Mondejar R, Lucas M. Molecular diagnosis in cerebral cavernous malformations. Neurologia 2015; 32:540-545. [PMID: 26304651 DOI: 10.1016/j.nrl.2015.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 06/29/2015] [Accepted: 07/02/2015] [Indexed: 11/27/2022] Open
Abstract
INTRODUCTION Cerebral cavernous malformations (CCMs; OMIM 116860) are enlarged vascular cavities without intervening brain parenchyma whose estimated prevalence in the general population is between 0.1% and 0.5%. Familial CCM is an autosomal dominant disease with incomplete clinical and radiological penetrance. Three genes have been linked to development of the lesions: CCM1/KRIT1, CCM2/MGC4607, and CCM3/PDCD10. DEVELOPMENT The aetiological mutation is not detected in a large percentage of cases and new approaches are therefore needed. The aim of this review is to analyse current molecular techniques and the possible mutations or variations which can be detected in a molecular genetics or molecular biology laboratory. Likewise, we will analyse other alternatives that may help detect mutations in those patients showing negative results. CONCLUSIONS A molecular diagnosis of cerebral cavernous malformations should provide at least the copy number variation and sequencing of CCM genes. In addition, appropriate genetic counselling is a crucial source of information and support for patients and their relatives.
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Affiliation(s)
- R Mondejar
- Servicio de Biología Molecular, UGC Bioquímica Clínica, Hospital Universitario Virgen Macarena, Sevilla, España.
| | - M Lucas
- Servicio de Biología Molecular, UGC Bioquímica Clínica, Hospital Universitario Virgen Macarena, Sevilla, España
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