Muscle hypertrophy as the presenting sign in a patient with a complete FHL1 deletion

Clin Genet. 2016 Aug;90(2):166-70. doi: 10.1111/cge.12695. Epub 2016 Jan 8.


Four and a half LIM protein 1 (FHL1/SLIM1) has recently been identified as the causative gene mutated in four distinct diseases affecting skeletal muscle that have overlapping features, including reducing body myopathy, X-linked myopathy, X-linked dominant scapuloperoneal myopathy and Emery-Dreifuss muscular dystrophy. FHL1 localises to the sarcomere and the sarcolemma and is believed to participate in muscle growth and differentiation as well as in sarcomere assembly. We describe in this case report a boy with a deletion of the entire FHL1 gene who is now 15 years of age and presented with muscle hypertrophy, reduced subcutaneous fat, rigid spine and short stature. This case is the first, to our knowledge, with a complete loss of the FHL1 protein and MAP7D3 in combination. It supports the theory that dominant negative effects (accumulation of cytotoxic-mutated FHL1 protein) worsen the pathogenesis. It extends the phenotype of FHL1-related myopathies and should prompt future testing in undiagnosed patients who present with unexplained muscle hypertrophy, contractures and rigid spine, particularly if male.

Keywords: Emery–Dreifuss; FHL1; muscular dystrophy; neuromuscular.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Gene Deletion*
  • Gene Expression
  • Humans
  • Hypertrophy / genetics*
  • Hypertrophy / pathology
  • Intracellular Signaling Peptides and Proteins / deficiency
  • Intracellular Signaling Peptides and Proteins / genetics*
  • LIM Domain Proteins / deficiency
  • LIM Domain Proteins / genetics*
  • Male
  • Microtubule-Associated Proteins / deficiency
  • Microtubule-Associated Proteins / genetics*
  • Muscle Proteins / deficiency
  • Muscle Proteins / genetics*
  • Muscular Diseases / genetics*
  • Muscular Diseases / pathology
  • Phenotype
  • Spine / metabolism
  • Spine / pathology*
  • Subcutaneous Fat / metabolism
  • Subcutaneous Fat / pathology*


  • FHL1 protein, human
  • Intracellular Signaling Peptides and Proteins
  • LIM Domain Proteins
  • MAP7D3 protein, human
  • Microtubule-Associated Proteins
  • Muscle Proteins

Supplementary concepts

  • Myostatin-related muscle hypertrophy