Variable presentation of the clinical phenotype of McArdle's disease in a kindred harbouring a novel compound genotype in the muscle glycogen phosphorylase gene

Neurosci Lett. 2005 Dec 31;391(1-2):28-31. doi: 10.1016/j.neulet.2005.08.026. Epub 2005 Sep 9.


We report a Spanish family with muscle glycogen phosphorylase (PYGM) deficiency (McArdle's disease) harbouring a novel compound genotype (A659D/L586P). Four individuals who had the same genotype for PYGM, showed a wide variability in the presentation of the clinical phenotype, including one patient with a restrictive respiratory pattern, which is unusual in McArdle's disease. Moreover, these patients were studied for the insertion/deletion (I/D) trait in the angiotensin converting enzyme (ACE) which has been suggested to be a strong modulator of severity in McArdle's disease. Our results indicate no association of the I/D ACE trait in this family, suggesting that other factors would be more relevant in determining the severity of the clinical presentation.

Publication types

  • Clinical Trial

MeSH terms

  • Aged
  • Family
  • Female
  • Genetic Predisposition to Disease / genetics
  • Genetic Variation / genetics
  • Genotype
  • Glycogen Phosphorylase, Muscle Form / genetics*
  • Glycogen Storage Disease Type V / epidemiology
  • Glycogen Storage Disease Type V / genetics
  • Glycogen Storage Disease Type V / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Muscles / metabolism*
  • Muscular Diseases / epidemiology
  • Muscular Diseases / genetics
  • Muscular Diseases / metabolism*
  • Pedigree
  • Phenotype
  • Polymorphism, Genetic
  • Risk Assessment / methods*
  • Risk Factors
  • Spain / epidemiology


  • Glycogen Phosphorylase, Muscle Form