Abstract
The dystrophin gene, which is mutated in Duchenne muscular dystrophy (DMD), is the largest known human gene and is characterized by the huge size of its introns. Intron 2, the second largest intron, is 170-kb long and has been shown to include a 140-bp cryptic exon (exon 2a) in its 5′ region. The rest of this intron has no known function. In this study, we find that another cryptic exon, located in the 3′ region of intron 2, is activated in a promoter- or tissue-specific manner. An unknown 98-bp insertion precisely between exons 2 and 3 was identified in one of the dystrophin mRNAs from lymphocytes of a DMD patient with a duplication of exon 2. This 98-bp sequence, located in the 3′ region of intron 2, was found to possess a branch point, acceptor and donor splice-site consensus sequences, and an exonic splicing enhancer sequence, and thus is a novel exon, which we named “exon 2b.” In lymphocytes, exon 2b incorporation was detected in the muscle-specific, promoter-driven transcript. Five of 20 normal human tissue mRNAs, including cardiac and skeletal muscle mRNAs, were confirmed to contain a fragment extending from exon 1 to exon 2b by reverse transcription PCR amplification, indicating that exon 2b is activated in a tissue-specific manner. This provides a clue to a novel cause of dystrophinopathy.
Similar content being viewed by others
Log in or create a free account to read this content
Gain free access to this article, as well as selected content from this journal and more on nature.com
or
References
Adachi K, Takeshima Y, Wada H, Yagi M, Nakamura H, Matsuo M (2003) Heterogous dystrophin mRNAs produced by a novel splice acceptor site mutation in intermediate dystrophinopathy. Pediatr Res 53:125–131
Ahn AH, Kunkel LM (1993) The structural and functional diversity of dystrophin. Nat Genet 3:283–291
Ars E, Serra E, Garcia J, Kruyer H, Gaona A, Lazaro C, Estivill X (2000) Mutations affecting mRNA splicing are the most common molecular defects in patients with neurofibromatosis type 1. Hum Mol Genet 9:237–247
Bardoni A, Felisari G, Sironi M, Comi G, Lai M, Robotti M, Bresolin N (2000) Loss of Dp140 regulatory sequences is associated with cognitive impairment in dystrophinopathies. Neuromuscul Disord 10:194–199
Beggs AH, Koenig M, Boyce FM, Kunkel LM (1990) Detection of 98% of DMD/BMD gene deletions by polymerase chain reaction. Hum Genet 86:45–48
Cartegni L, Wang J, Zhu Z, Zhang MQ, Krainer AR (2003) ESEfinder: a web resource to identify exonic splicing enhancers. Nucleic Acids Res 31:3568–3571
Chamberlain JS, Gibbs RA, Ranier JE, Nguyen PN, Caskey CT (1988) Deletion screening of the Duchenne muscular dystrophy locus via multiplex DNA amplification. Nucleic Acids Res 16:11141–11156
Chelly J, Gilgenkrantz H, Hugnot J, Hamard G, Lambert M, Recan D, Akli S, Cometto M, Kahn A, Kaplan J (1991) Illegitimate transcription. Application to the analysis of truncated transcripts of the dystrophin gene in nonmuscle cultured cells from Duchenne and Becker patients. J Clin Invest 88:1161–1166
Chillon M, Dork T, Casals T, Gimenez J, Fonknechten N, Will K, Ramos D, Nunes V, Estivill X (1995) A novel donor splice site in intron 11 of the CFTR gene, created by mutation 1811+1.6kbA→G, produces a new exon: high frequency in Spanish cystic fibrosis chromosomes and association with severe phenotype. Am J Hum Genet 56:623–629
Cooper TA, Mattox W (1997) The regulation of splice-site selection, and its role in human disease. Am J Hum Genet 61:259–266
D’Souza VN, Nguyen TM, Morris GE, Karges W, Pillers DA, Ray PN (1995) A novel dystrophin isoform is required for normal retinal electrophysiology. Hum Mol Genet 4:837–842
Dwi Pramono ZA, Takeshima Y, Surono A, Ishida T, Matsuo M (2000) A novel cryptic exon in intron 2 of the human dystrophin gene evolved from an intron by acquiring consensus sequences for splicing at different stages of anthropoid evolution. Biochem Biophys Res Commun 267:321–328
Eng L, Coutinho G, Nahas S, Yeo G, Tanouye R, Babaei M, Dork T, Burge C, Gatti RA (2004) Nonclassical splicing mutations in the coding and noncoding regions of the ATM Gene: maximum entropy estimates of splice junction strengths. Hum Mutat 23:67–76
Felisari G, Martinelli Boneschi F, Bardoni A, Sironi M, Comi GP, Robotti M, Turconi AC, Lai M, Corrao G, Bresolin N (2000) Loss of Dp140 dystrophin isoform and intellectual impairment in Duchenne dystrophy. Neurology 55:559–564
Ferlini A, Muntoni F (1998) The 5′ region of intron 11 of the dystrophin gene contains target sequences for mobile elements and three overlapping ORFs. Biochem Biophys Res Commun 242:401–406
Ferlini A, Sewry C, Melis MA, Mateddu A, Muntoni F (1999) X-linked dilated cardiomyopathy and the dystrophin gene. Neuromuscul Disord 9:339–346
Galante PA, Sakabe NJ, Kirschbaum-Slager N, de Souza SJ (2004) Detection and evaluation of intron retention events in the human transcriptome. Rna 10:757–765
Giliberto F, Ferreiro V, Dalamon V, Szijan I (2004) Dystrophin deletions and cognitive impairment in Duchenne/Becker muscular dystrophy. Neurol Res 26:83–87
Graveley BR (2005) Small molecule control of pre-mRNA splicing. Rna 11:355–358
Hagiwara Y, Nishio H, Kitoh Y, Takeshima Y, Narita N, Wada H, Yokoyama M, Nakamura H, Matsuo M (1994) A novel point mutation (G−1 to T) in a 5′ splice donor site of intron 13 of the dystrophin gene results in exon skipping and is responsible for Becker muscular dystrophy. Am J Hum Genet 54:53–61
Highsmith WE, Burch LH, Zhou Z, Olsen JC, Boat TE, Spock A, Gorvoy JD, Quittel L, Friedman KJ, Silverman LM et al (1994) A novel mutation in the cystic fibrosis gene in patients with pulmonary disease but normal sweat chloride concentrations. N Engl J Med 331:974–980
Krawczak M, Reiss J, Cooper DN (1992) The mutational spectrum of single base-pair substitutions in mRNA splice junctions of human genes: causes and consequences. Hum Genet 90:41–54
Malhotra SB, Hart KA, Klamut HJ, Thomas NST, Bodrug E, Burghes AHM, Borrow M, Harper PS, Thompson W, Ray PN, Worton RG (1988) Frame-shift deletions in patients with Duchenne and Becker muscular dystrophy. Science 242:755–759
Matsuo M, Masumura T, Nishio H, Nakajima T, Kitoh Y, Takumi T, Koga J, Nakamura H (1991) Exon skipping during splicing of dystrophin mRNA precursor due to an intraexon deletion in the dystrophin gene of Duchenne muscular dystrophy Kobe. J Clin Invest 87:2127–2131
Muntoni F, Gobbi P, Sewry C, Sherratt T, Taylor J, Sandhu SK, Abbs S, Roberts R, Hodgson SV, Bobrow M, Dubowits V (1994) Deletions in the 5′ region of dystrophin and resulting phenotypes. J Med Genet 31:843–847
Nishio H, Takeshima Y, Narita N, Yanagawa H, Suzuki Y, Ishikawa Y, Minami R, Nakamura H, Matsuo M (1994) Identification of a novel first exon in the human dystrophin gene and of a new promoter located more than 500 kb upstream of the nearest known promoter. J Clin Invest 94:1037–1042
Pagani F, Buratti E, Stuani C, Bendix R, Dork T, Baralle FE (2002) A new type of mutation causes a splicing defect in ATM. Nature Genet 30:426–429
Reiss J, Rininsland F (1994) An explanation for the constitutive exon 9 cassette splicing of the DMD gene. Hum Mol Genet 3:295–298
Roberts RG, Bentley DR, Bobrow M (1993) Infidelity in the structure of ectopic transcripts: a novel exon in lymphocyte dystrophin transcripts. Hum Mutat 2:293–299
Roca X, Sachidanandam R, Krainer AR (2003) Intrinsic differences between authentic and cryptic 5′ splice sites. Nucleic Acids Res 31:6321–6333
Schaal TD, Maniatis T (1999) Selection and characterization of pre-mRNA splicing enhancers: identification of novel SR protein-specific enhancer sequences. Mol Cell Biol 19:1705–1719
Senapathy P, Shapiro MB, Harris NL (1990) Splice junctions, branch point sites, and exons: sequence statistics, identification, and applications to genome project. Methods Enzymol 183:252–278
Shapiro MB, Senapathy P (1987) RNA splice junctions of different classes of eukaryotes: sequence statistics and functional implications in gene expression. Nucleic Acids Res 15:7155–7174
Sironi M, Menozzi G, Riva L, Cagliani R, Comi GP, Bresolin N, Giorda R, Pozzoli U (2004) Silencer elements as possible inhibitors of pseudoexon splicing. Nucleic Acids Res 32:1783–1791
Suminaga R, Takeshima Y, Adachi K, Yagi M, Nakamura H, Matsuo M (2002) A novel cryptic exon in intron 3 of the dystrophin gene was incorporated into dystrophin mRNA with a single nucleotide deletion in exon 5. J Hum Genet 47:196–201
Sun H, Chasin LA (2000) Multiple splicing defects in an intronic false exon. Mol Cell Biol 20:6414–6425
Surono A, Takeshima Y, Wibawa T, Pramono ZA, Matsuo M (1997) Six novel transcripts that remove a huge intron ranging from 250 to 800 kb are produced by alternative splicing of the 5′ region of the dystrophin gene in human skeletal muscle. Biochem Biophys Res Commun 239:895–899
Surono A, Takeshima Y, Wibawa T, Ikezawa M, Nonaka I, Matsuo M (1999) Circular dystrophin RNAs consisting of exons that were skipped by alternative splicing. Hum Mol Genet 8:493–500
Torelli S, Muntoni F (1996) Alternative splicing of dystrophin exon 4 in normal human muscle. Hum Genet 97:521–523
Tuffery-Giraud S, Saquet C, Chambert S, Claustres M (2003) Pseudoexon activation in the DMD gene as a novel mechanism for Becker muscular dystrophy. Hum Mutat 21:608–614
Vervoort R, Gitzelmann R, Lissens W, Liebaers I (1998) A mutation (IVS8+0.6kbdelTC) creating a new donor splice site activates a cryptic exon in an Alu-element in intron 8 of the human beta-glucuronidase gene. Hum Genet 103:686–693
Wang M, Dotzlaw H, Fuqua SAW, Murphy LC (1997) A point mutation in the human estrogen receptor gene is associated with the expression of an abnormal estrogen receptor mRNA containing a 69 novel nucleotide insertion. Breast Cancer Res Treat 44:145–151
Winnard AV, Jia-Hsu Y, Gibbs RA, Mendell JR, Burghes AH (1992) Identification of a 2 base pair nonsense mutation causing a cryptic splice site in a DMD patient. Hum Mol Genet 1:645–646
Winnard AV, Mendell JR, Prior TW, Florence J, Burghes HM (1995) Frameshift deletions of exons 3–7 and revertant fibers in Duchenne muscular dystrophy: mechanisms of dystrophin production. Am J Hum Genet 56:158–166
Wuarin J, Schibler U (1994) Physical isolation of nascent RNA chains transcribed by RNA polymerase II: evidence for cotranscriptional splicing. Mol Cell Biol 14:7219–7225
Yagi M, Takeshima Y, Wada H, Nakamura H, Matsuo M (2003) Two alternative exons can result from activation of the cryptic splice acceptor site deep within intron 2 of the dystrophin gene in a patient with as yet asymptomatic dystrophinopathy. Hum Genet 112:164–170
Acknowledgements
We acknowledge Ms. A. Hosoda for her secretarial help. This work was supported by grants from the Ministry of Education, Science, Sports, and Culture of Japan and the Health and Labor Science Research (Research on Psychiatric and Neurological Diseases and Mental Health), the Research Grant for Nervous and Mental Disorders from the Ministry of Health, Labor, and Welfare, and the Mitsubishi Foundation.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Tran, V.K., Zhang, Z., Yagi, M. et al. A novel cryptic exon identified in the 3′ region of intron 2 of the human dystrophin gene. J Hum Genet 50, 425–433 (2005). https://doi.org/10.1007/s10038-005-0272-6
Received:
Accepted:
Published:
Issue date:
DOI: https://doi.org/10.1007/s10038-005-0272-6
Keywords
This article is cited by
-
DMD transcripts in CRL-2061 rhabdomyosarcoma cells show high levels of intron retention by intron-specific PCR amplification
Cancer Cell International (2017)
-
Normal and altered pre-mRNA processing in the DMD gene
Human Genetics (2017)
-
Tissue- and case-specific retention of intron 40 in mature dystrophin mRNA
Journal of Human Genetics (2015)
-
Whole dystrophin gene analysis by next-generation sequencing: a comprehensive genetic diagnosis of Duchenne and Becker muscular dystrophy
Molecular Genetics and Genomics (2014)
-
Molecular characterization of an X(p21.2;q28) chromosomal inversion in a Duchenne muscular dystrophy patient with mental retardation reveals a novel long non-coding gene on Xq28
Journal of Human Genetics (2013)


