Genetics

• myophosphorylase normally initiates glycogen breakdown by removing 1,4-glucosyl groups from the glycogen molecule with release of glucose-1-phosphate
  • the majority patients with McAd have undetectable myophosphorylase activity and, thus, are unable to release glucose from glycogen in muscle
  • gene for myophosphorylase has been to chromosome 11q13
  • family history is positive in about half of the patients and consistent with autosomal recessive inheritance. However there does appear to be an autosomal dominant transmission in some families

Reference:

1. Bollig G et al. McArdle's disease and anaesthesia: Case reports. Review of potential problems and association with malignant hyperthermia. Acta Anaesthesiologica Scandinavica 2005;49 (8): 1077-1083.