2 Clinical Trials for Various Conditions
Background: Congenital myopathies (CM) are genetic disorders that can cause decreased muscle tone and muscle weakness. Most CMs in the United States are related to the ryanodine receptor 1 (RYR1) gene. Researchers need more natural history data to learn about these CMs in children and adults. Objective: To learn more about the signs, symptoms, and course of RYR1-related disorders. Eligibility: People aged 7 years and older with an RYR1-related disorder. Design: Ambulatory participants will come to the Clinical Center and non-ambulatory participants will visit via telehealth. Visits will be once a year for 3 or 5 years. Clinical Center visits will take 2 to 3 days. All participants will undergo tests including: Photos and videos. These will be taken to document the participant s condition. Blood and urine tests. Activity Tracker. Participants will wear a device to record their activity. Questionnaires. Participants will answer questions about their health, pain, fatigue, stress, quality of life, and other topics. Participants who visit the Clinical Center will also undergo: Tests of heart and lung function. Motor skills and strength tests. Participants will walk, climb stairs, kneel, crawl, stand up, and perform other movements to test their strength and abilities. They will squeeze and pinch a handheld device to test their grip. Imaging scans. Skin biopsy. Adult participants may opt to have a sample of skin taken (one time only). Eye exam
Background: - Ryanodine receptor type 1-related myopathies (RYR1-RM) are the most common non-dystrophic 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. Objectives: - To see if the drug N-acetylcysteine decreases muscle damage in people with RYR1-RM. To see if it improves their exercise tolerance. Eligibility: - People age 7 and older with a confirmed genetic diagnosis of RYR1 or a clinical diagnosis of RYR1 and a family member with a confirmed genetic diagnosis. Design: * Participants will be screened with a checklist of criteria. Adult participants may have a muscle biopsy. A needle will remove a tiny piece of muscle in the lower leg. * Study visits will take several days. * Visit 1: * Medical history * Physical exam * Blood, urine, and saliva tests * Questions about symptoms and quality of life * Heart, lung, and walking tests * Muscle Oxygenation Capacity Test. A blood pressure cuff around the thigh will be tightened for up to 10 minutes. * Biodex testing, stretching the leg against resistance * Muscle ultrasounds. A probe will be moved over the skin. * Participants may be photographed or videotaped during procedures. * They may have a muscle biopsy. * Six months later, visit 2 will repeat visit 1. Participants will start taking the study drug dissolved in water or placebo three times a day for 6 months. * Participants will stay at NIH for 2 days after starting the study drug. * Participants will be contacted by phone during the study to monitor side effects * Six months after starting the study drug, study visit 3 will repeat some or all of visit 1.