Causes and Risk Factors for Myopathy

Inheritable myopathies are caused by a genetic defect. The most common muscular dystrophies—Duchenne MD and Becker MD—result from a genetic defect on the X chromosome.

Risk factors for other types of myopathy include the following:

  • Autoimmune disorders (e.g., myasthenia gravis, scleroderma, thyroiditis)
  • Endocrine disorders (e.g., Cushing syndrome, hypothyroidism, hyperthyroidism, Addison disease)
  • Exposure to toxins (e.g., herbicides, insecticides, flame retardant chemicals)
  • Infection (e.g., HIV, Lyme disease, trichinosis)
  • Vitamin D deficiency, vitamin E or A toxicity
  • Medication (e.g., some antihistamines, long-term corticosteroid use)
  • Metabolic disorder (e.g., glycogen and lipid storage diseases)

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 01 Jan 2000

Last Modified: 25 Sep 2015