Novel mutations in three patients with LGMD2C with phenotypic differences

Pediatr Neurol. 2004 Apr;30(4):291-4. doi: 10.1016/j.pediatrneurol.2003.11.006.

Abstract

Limb-girdle muscular dystrophy type 2C is an autosomal-recessive disorder caused by mutations in gamma-sarcoglycan encoding gene. This disease is characterized by childhood onset of progressive muscular dystrophy. Because of the clinical presentation, this disorder may be misdiagnosed as a dystrophinopathy. Two males (Patients A and B) from one Turkish family and one male (Patient C) from a Moroccan family had progressive walking disturbances for several years, exercise intolerance, and leg pains. Clinical examination revealed limb-girdle weakness and calf hypertrophy. Serum creatine kinase levels ranged from 1100 to 19000 U/L. The initial findings and course of the disease were less severe in Patient B compared with his brother (Patient A) at the same age. By means of immunohistochemistry on muscle biopsy all patients manifested reduced expression of alpha-, beta-, gamma-, and delta-sarcoglycans. DNA sequence analysis revealed a homozygous splice site mutation in exon 5 (IVS5+2T>C) in the Turkish family. In the patient from the Moroccan family a homozygous nonsense mutation in exon 2 (93G>A;Trp31X) was present. In conclusion, this report describes the clinical, histologic, and immunohistochemical characteristics of three children with limb-girdle muscular dystrophy type 2C. Two novel mutations in the gamma-sarcoglycan gene were present. We found phenotypic differences in two brothers.

MeSH terms

  • Biopsy
  • Child
  • Child, Preschool
  • Chromosome Aberrations*
  • Codon, Nonsense / genetics*
  • Consanguinity
  • Cytoskeletal Proteins / genetics*
  • DNA Mutational Analysis*
  • Diagnosis, Differential
  • Dystroglycans
  • Exons / genetics*
  • Genes, Recessive / genetics*
  • Homozygote
  • Humans
  • Male
  • Membrane Glycoproteins / genetics*
  • Muscle, Skeletal / pathology
  • Muscular Dystrophies / diagnosis
  • Muscular Dystrophies / genetics*
  • Muscular Dystrophies / pathology
  • Neurologic Examination
  • Phenotype*

Substances

  • Codon, Nonsense
  • Cytoskeletal Proteins
  • DAG1 protein, human
  • Membrane Glycoproteins
  • Dystroglycans