Natural History Study of Mitochondrial Myopathy

MM Cohort Inclusion Criteria 1. Males or females age 0-100 years of age 2. Mitochondrial disorder established by confirmed genetic or biochemical mutation in mtDNA or nuclear DNA OR is suitable for participation in the opinion of the investigator based on clinical presentation. 3. Exhibits myopathy (exercise intolerance, muscle strength, fatigue) relating to Mitochondrial disease in the opinion of the investigator 4. Able to provide written consent OR parental permission and child assent OR if they are an adult with diminished capacity, an LAR or healthcare representative is able to and willing to provide consent ., as approved by the appropriate Institutional Review Board (IRB) or Ethics Committee (EC) MM Cohort Exclusion Criteria 1. Male or female fetuses 2. Non English speakers 3. Parents/guardians or subjects who, in the opinion of the Investigator, may be non-compliant with study schedules or procedures. 4. Subjects that do not meet all of the enrollment criteria may not be enrolled. Any violations of these criteria must be reported in accordance with IRB Policies and Procedures. Healthy Control Cohort Inclusion Criteria 1. Males or females age 0-100 years of age 2. No history of mitochondrial myopathy symptoms 3. Able to provide written consent or parental permission and child assent., approved by the appropriate Institutional Review Board (IRB) or Ethics Committee (EC) 4. Individual is not a study staff member or a family member of a study staff member (not listed as a study staff in eIRB) Healthy Control Exclusion Criteria 1. Male or female fetuses 2. Non English speakers 3. Mitochondrial disorder established by confirmed genetic or biochemical mutation in mtDNA or nuclear DNA 4. Exhibits myopathy (exercise intolerance, muscle strength, fatigue) relating to Mitochondrial disease 5. Parents/guardians or subjects who, in the opinion of the Investigator, may be non-compliant with study schedules or procedures. 6. Individual is listed as a study staff member in eIRB, OR individual is a family member of a study staff member listed in eIRB 7. Subjects that do not meet all of the enrollment criteria may not be enrolled. Any violations of these criteria must be reported in accordance with IRB Policies and Procedures.