Laing early-onset distal myopathy in a Belgian family

P Y K Van den Bergh1, J J Martin, F Lecouvet

  • 1Neuromuscular Reference Centre, UCL St-Luc, Department of Neurology, University Hospitals St-Luc, University of Louvain, Avenue Hippocrate 10, 1200, Brussels, Belgium, peter.vandenbergh@uclouvain.be.

Insights

This study identifies the first Belgian family with Laing early-onset distal myopathy (MPD1), a genetic muscle disorder. A novel MYH7 mutation was found, offering insights into this rare condition.

Area of Science:

  • Neurology
  • Genetics
  • Rare Diseases

Background:

  • Laing early-onset distal myopathy (MPD1) is a rare genetic neuromuscular disorder.
  • Early diagnosis and genetic identification are crucial for understanding disease progression and management.

Observation:

  • The first Belgian family with MPD1 presented with early-onset muscle weakness, starting with limping and progressing to severe proximal and distal muscle involvement.
  • Clinical manifestations included foot drop, neck flexor weakness, and progressive distal limb extensor weakness.
  • Electromyography (EMG) revealed characteristic abnormal muscle electrical activity, while creatine kinase (CK) levels and nerve conduction studies remained normal.

Findings:

  • Genetic analysis identified a specific MYH7 gene mutation (c.4522_4524del, p.Glu1508del) in affected individuals.
  • This mutation appears to be de novo, consistent with previous reports in other European populations.
  • Muscle biopsies showed non-specific myopathic changes, congenital fiber type disproportion, and denervation-reinnervation patterns, complicating initial diagnosis.

Implications:

  • This case expands the known geographic distribution of MPD1 and highlights the importance of genetic testing for MYH7 mutations in suspected early-onset distal myopathies.
  • Understanding this de novo mutation's role can aid in developing diagnostic criteria and potential therapeutic strategies for MPD1.
  • The findings underscore the diagnostic challenges posed by variable muscle biopsy results in MPD1.

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