{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,18]],"date-time":"2025-09-18T10:47:16Z","timestamp":1758192436440,"version":"3.44.0"},"reference-count":18,"publisher":"Necmettin Erbakan University Press","issue":"03","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Pediatr Genet"],"published-print":{"date-parts":[[2023,9]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>X-linked myotubular myopathy (XLMTM), a centronuclear congenital myopathy secondary to pathogenic variants in the MTM1 gene encoding myotubularin, is typically recognized for its classic and severe phenotype which includes neonatal hypotonia, severe muscle weakness, long-term ventilator dependence, markedly delayed gross motor milestones with inability to independently ambulate, and a high neonatal and childhood mortality. However, milder congenital forms of the condition and other phenotypes are recognized. We describe a 6-year-old boy with a mild XLMTM phenotype with independent gait and no respiratory insufficiency even in the neonatal period. The child has a hemizygous novel splice site variant in the MTM1 gene (c.232\u201325A\u2009&gt;\u2009T) whose pathogenicity was confirmed by cDNA studies (exon 5 skipping) and muscle biopsy findings. We also compared the phenotype of our patient with the few reported cases that presented a mild XLMTM phenotype and no respiratory distress at birth, and discussed the potential mechanisms underlying this phenotype such as the presence of residual expression of the normal myotubularin transcript.<\/jats:p>","DOI":"10.1055\/s-0041-1728745","type":"journal-article","created":{"date-parts":[[2021,6,1]],"date-time":"2021-06-01T20:45:51Z","timestamp":1622580351000},"page":"258-262","source":"Crossref","is-referenced-by-count":0,"title":["X-Linked Myotubular Myopathy: A Novel Mutation Expanding the Genotypic Spectrum of a Phenotypically Heterogeneous Myopathy"],"prefix":"10.53391","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6616-4011","authenticated-orcid":false,"given":"Andreia","family":"Carvalho","sequence":"additional","affiliation":[{"name":"Neurology Department, Centro Hospitalar de Vila Nova de Gaia\u2013Espinho, Portugal"}]},{"given":"Carmen","family":"Costa","sequence":"additional","affiliation":[{"name":"Pediatric Neurology Department, Centro de Desenvolvimento da Crian\u00e7a, Hospital Pedi\u00e1trico de Coimbra - Centro Hospitalar e Universit\u00e1rio de Coimbra, Coimbra, Portugal"}]},{"given":"Miguel","family":"Pinto","sequence":"additional","affiliation":[{"name":"Neuropathology Unit, Hospital de Santo Ant\u00f3nio - Centro Hospitalar Universit\u00e1rio do Porto, Porto, Portugal"}]},{"given":"Ricardo","family":"Taipa","sequence":"additional","affiliation":[{"name":"Neuropathology Unit, Hospital de Santo Ant\u00f3nio - Centro Hospitalar Universit\u00e1rio do Porto, Porto, Portugal"},{"name":"Unit for Multidisciplinary Research In Biomedicine, Instituto de Ci\u00eancias Biom\u00e9dicas Abel Salazar, Universidade do Porto, Porto, Portugal"}]},{"given":"Ana","family":"Gon\u00e7alves","sequence":"additional","affiliation":[{"name":"Unit for Multidisciplinary Research In Biomedicine, Instituto de Ci\u00eancias Biom\u00e9dicas Abel Salazar, Universidade do Porto, Porto, Portugal"},{"name":"Molecular Genetics Unit, Centro de Gen\u00e9tica M\u00e9dica Dr. Jacinto Magalh\u00e3es, Centro Hospitalar Universit\u00e1rio do Porto, Porto, Portugal"}]},{"given":"M\u00e1rcia E.","family":"Oliveira","sequence":"additional","affiliation":[{"name":"Unit for Multidisciplinary Research In Biomedicine, Instituto de Ci\u00eancias Biom\u00e9dicas Abel Salazar, Universidade do Porto, Porto, Portugal"},{"name":"Molecular Genetics Unit, Centro de Gen\u00e9tica M\u00e9dica Dr. Jacinto Magalh\u00e3es, Centro Hospitalar Universit\u00e1rio do Porto, Porto, Portugal"}]},{"given":"Sofia","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Pulmonology Department, Hospital Pedi\u00e1trico de Coimbra - Centro Hospitalar e Universit\u00e1rio de Coimbra, Coimbra, Portugal"}]},{"given":"Joana Afonso","family":"Ribeiro","sequence":"additional","affiliation":[{"name":"Pediatric Neurology Department, Centro de Desenvolvimento da Crian\u00e7a, Hospital Pedi\u00e1trico de Coimbra - Centro Hospitalar e Universit\u00e1rio de Coimbra, Coimbra, Portugal"}]}],"member":"31409","published-online":{"date-parts":[[2021,6,1]]},"reference":[{"issue":"02","key":"ref1","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1038\/ng0696-175","article-title":"A gene mutated in X-linked myotubular myopathy defines a new putative tyrosine phosphatase family conserved in yeast","volume":"13","author":"J Laporte","year":"1996","journal-title":"Nat Genet"},{"issue":"02","key":"ref3","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1016\/S0022-3476(99)70417-8","article-title":"Medical complications in long-term survivors with X-linked myotubular myopathy","volume":"134","author":"G E Herman","year":"1999","journal-title":"J Pediatr"},{"issue":"01","key":"ref4","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1016\/1090-3798(98)01004-9","article-title":"X-linked myotubular 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