Mitochondrial Disease


Test in Focus

Mitochondrial disease is a progressive, multi-system neurodegenerative illness with a highly variable clinical presentation. In this "Test in Focus" episode of the "Answers From the Lab" podcast, Linda Hasadsri, M.D., Ph.D., discusses how advanced testing through Mayo Clinic Laboratories can expedite diagnosis for the challenging condition.

“Mitochondrial patients, at least in the Mayo experience, have to wait an average of approximately 12 years before they finally receive a diagnosis,” Dr. Hasadsri says. “A number of mitochondriopathies are actually treatable, and a timely diagnosis can really change the entire clinical course for a patient and their family.”

Mayo Clinic Laboratories offers a full suite of biochemical and molecular testing for mitochondrial diseases under one roof. Our molecular tests utilize custom-designed sequencing reagents and employ a pioneering methodology known as droplet digital PCR to determine heteroplasmy.

“We are the first and only lab that I know of in the world that utilizes this technology for this purpose, and it’s the only methodology that is truly quantitative,” Dr. Hasadsri says. “Accurate and sensitive determination of heteroplasmy is incredibly important, not just diagnostically, but also for the clinical management and prognostication in these patients.”

Listen to learn more about how mitochondrial disease testing can accelerate diagnosis and provide patients and providers insight about disease progression and treatment options.

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Testing

Useful information

  • Diagnosis of mitochondrial disease that results from variants in either nuclear-encoded genes or the mitochondrial genome
  • A second-tier test for patients in whom previous targeted gene variant analyses for specific mitochondrial disease-related genes were negative
  • Identification of variants known to be associated with mitochondrial disease, allowing for predictive testing of at-risk family members

Specimen requirements

Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.

Submit only 1 of the following specimens:

Specimen Type: Whole blood

  • Container/Tube:
    • Preferred: Lavender top (EDTA) or yellow top (ACD)
    • Acceptable: Any anticoagulant
    • Specimen Volume: 3 mL
    • Collection Instructions:
      • Invert several times to mix blood.
      • Send specimen in original tube.
    • Specimen Stability Information: Ambient (preferred)/Refrigerated
    • Additional Information: To ensure minimum volume and concentration of DNA is met, the preferred volume of blood must be submitted. Testing may be canceled if DNA requirements are inadequate.

Specimen Type: Cultured fibroblasts

  • Container/Tube: T-75 or T-25 flask
    • Specimen Volume: 1 Full T-75 or 2 full T-25 flasks
    • Specimen Stability Information: Ambient (preferred)/Refrigerated <24 hours

Specimen Type: Skin biopsy

  • Supplies: Fibroblast Biopsy Transport Media (T115)
    • Container/Tube: Sterile container with any standard cell culture media (eg, minimal essential media, RPMI 1640). The solution should be supplemented with 1% penicillin and streptomycin.
    • Specimen Volume: 4-mm punch
    • Specimen Stability Information: Refrigerated (preferred)/Ambient

Specimen Type: Tissue biopsy

  • Supplies: Muscle Biopsy Kit (T541)
    • Collection Instructions: Prepare and transport specimen per instructions in Muscle Biopsy Specimen Preparation Sheet in Special Instructions.
    • Specimen Volume: 10-80 mg
    • Specimen Stability Information: Frozen (preferred)/Ambient/Refrigerated

Performance information

  • Analytic time: 8 to 10 weeks
  • Day(s) and time(s) performed: Varies

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Samantha Rossi (@samantharossi)

Samantha Rossi

Samantha Rossi is a Digital Marketing Manager at Mayo Clinic Laboratories. She supports marketing strategies for product management and specialty testing. Samantha has worked at Mayo Clinic since 2019.