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Antioxidant Therapy in RYR1-Related Congenital Myopathy (N-Acetylcysteine)

The National Institute of Nursing research (NINR) at the National Institute of Health (NIH) in Bethesda, Maryland, is conducting a research study to determine if a drug that has been approved by the FDA for other indications reduces the severity of some symptoms in people with ryanodine receptor 1-related myopathy (RYR1-RM) 



Ryanodine receptor type 1-related myopathies (RYR1-RM) are the most common muscle diseases that people are born with in the U.S. They affect development, muscles, and walking. Researchers want to test a new drug to help people with these diseases.


To see if the drug N-acetylcysteine decreases muscle damage in people with RYR1-RM. To see if it improves their exercise tolerance.

You may be eligible if you: 

  • are 7 years of age or older (Parents must give permission for minors to participate). 
  • are able to walk. 
  • have a diagnosis of RYR1.
  • have had a muscle biopsy confirming RYR1, or if anyone in your family does.

You may not be eligible if you: 

  • have a history of liver or lung disease.
  • have a history of ulcers, trouble swallowing, or have problems with your esophagus.
  • are pregnant or are planning to become pregnant.
  • are nursing or breastfeeding.

The study involves: 

  • Three outpatient visits to the NIH campus over one year. 
  • After your initial visit, you will be seen twice, 6 months apart. 
  • Each visit will take 4-6 days. 
  • You will be required to take the drug or placebo three times a day for 6 months.
  • Travel and accommodation expenses will be covered for participants.
  • All study-related tests are provided at no cost. 

The NIH Clinical Center, America's research hospital, is located on the Metro red line (Medical Center station) in Bethesda, Maryland. 

For more information contact: 
Irene Arveson, BSN, RN 
E-mail:  This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Phone: 301-451-4881
Refer to study 15-NR-0072