| المساهمون: |
Institut Català de la Salut, [Bosco L] Genetics and Rare Diseases Research Division, Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy. Department of Science, University 'Roma Tre', Rome, Italy. [Leone D] Centro Clinico Nemo, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Roma, Italy. [Costa Comellas L] Servei de Neurologia Pediàtrica, Vall d’Hebron Hospital Universitari, Barcelona, Spain. Vall d’Hebron Institut de Recerca (VHIR), Barcelona, Spain. [Monforte M] UOC di Neurologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy. [Pane M, Mercuri E] Centro Clinico Nemo, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Roma, Italy. Pediatric Neurology, Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy, Vall d'Hebron Barcelona Hospital Campus |
| الوصف: |
Myotubular myopathy; Novel mutation; Splicing Miopatía miotubular; Nueva mutación; Empalme Miopatia miotubular; Nova mutació; Empalmament X-linked myotubular myopathy (XLMTM) is a severe form of centronuclear myopathy, characterized by generalized weakness and respiratory insufficiency, associated with pathogenic variants in the MTM1 gene. NGS targeted sequencing on the DNA of a three-month-old child affected by XLMTM identified the novel hemizygous MTM1 c.1261-5T>G intronic variant, which interferes with the normal splicing process, generating two different abnormal transcripts simultaneously expressed in the patient’s muscular cells. The first aberrant transcript, induced by the activation of a cryptic splice site in intron 11, includes four intronic nucleotides upstream of exon 12, resulting in a shift in the transcript reading frame and introducing a new premature stop codon in the catalytic domain of the protein (p.Arg421SerfsTer7). The second aberrant MTM1 transcript, due to the lack of recognition of the 3′ acceptor splice site of intron 11 from the spliceosome complex, leads to the complete skipping of exon 12. We expanded the genotypic spectrum of XLMTM underlying the importance of intron–exons boundaries sequencing in male patients affected by XLMTM. |
