MYH7-related myopathies: Clinical, histopathological and imaging findings in a cohort of Italian patients

Chiara Fiorillo, Guja Astrea, Marco Savarese, Denise Alessandra Cassandrini, Giacomo Brisca, Federica Trucco, Marina Pedemonte, Rosanna Trovato, Lucia Ruggiero, Liliana Vercelli, Adele D'Amico, Giorgio Tasca, M. Pane, Marina Fanin, L. Bello, Paolo Broda, Olimpia Musumeci, C. Rodolico, S. Messina, Gian Luca VitaMaria Sframeli, S. Gibertini, Lucia Morandi, Marina Mora, Lorenzo Maggi, Antonio Petrucci, Roberto Massa, M. Grandis, Antonio Toscano, E. Pegoraro, E. Mercuri, Enrico Silvio Bertini, T. Mongini, Lucio Santoro, Vincenzo Nigro, Carlo Minetti, Filippo Maria Santorelli, Claudio Bruno

Research output: Contribution to journalArticle

Abstract

Background: Myosin heavy chain 7 (MYH7)-related myopathies are emerging as an important group of muscle diseases of childhood and adulthood, with variable clinical and histopathological expression depending on the type and location of the mutation. Mutations in the head and neck domains are a well-established cause of hypertrophic cardiomyopathy whereas mutation in the distal regions have been associated with a range of skeletal myopathies with or without cardiac involvement, including Laing distal myopathy and Myosin storage myopathy. Recently the spectrum of clinical phenotypes associated with mutations in MYH7 has increased, blurring this scheme and adding further phenotypes to the list. A broader disease spectrum could lead to misdiagnosis of different congenital myopathies, neurogenic atrophy and other neuromuscular conditions. Results: As a result of a multicenter Italian study we collected clinical, histopathological and imaging data from a population of 21 cases from 15 families, carrying reported or novel mutations in MYH7. Patients displayed a variable phenotype including atypical pictures, as dropped head and bent spine, which cannot be classified in previously described groups. Half of the patients showed congenital or early infantile weakness with predominant distal weakness. Conversely, patients with later onset present prevalent proximal weakness. Seven patients were also affected by cardiomyopathy mostly in the form of non-compacted left ventricle. Muscle biopsy was consistent with minicores myopathy in numerous cases. Muscle MRI was meaningful in delineating a shared pattern of selective involvement of tibialis anterior muscles, with relative sparing of quadriceps. Conclusion: This work adds to the genotype-phenotype correlation of MYH7-relatedmyopathies confirming the complexity of the disorder.

Original languageEnglish
Article number91
JournalOrphanet Journal of Rare Diseases
Volume11
Issue number1
DOIs
Publication statusPublished - Jul 7 2016

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Keywords

  • Distal myopathy
  • Muscle biopsy
  • Muscle MRI
  • Myosin heavy chain
  • Whole exome sequencing

ASJC Scopus subject areas

  • Medicine(all)
  • Genetics(clinical)
  • Pharmacology (medical)

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