Mitochondrial condition guide

Single large-scale mtDNA deletion syndromes

A spectrum including Pearson syndrome, Kearns–Sayre syndrome, and progressive external ophthalmoplegia, with features that vary by age and affected tissues.

Symptoms and organ systems

A spectrum including Pearson syndrome, Kearns–Sayre syndrome, and progressive external ophthalmoplegia, with features that vary by age and affected tissues.

Presentation can vary by age, variant, heteroplasmy where relevant, and affected tissues. A person may have only some associated features, and similar symptoms can have other causes.

Genetics and inheritance

Common genetic association: Mitochondrial DNA deletion.

The same gene or mitochondrial DNA change can produce different symptoms and severity. Inheritance and recurrence risk depend on the specific molecular finding; a genetics professional should interpret results in the individual and family context.

Diagnostic pathway

Evaluation may combine history, examination, molecular testing, biochemical studies, imaging, and organ-specific assessments. No single pathway fits every person.

Management and monitoring

Care is individualized and often multidisciplinary. Monitoring priorities depend on the condition, symptoms, age, and specialist guidance.

Natural history

Registries and repeated follow-up help describe onset, progression, stability, and variation, but group patterns do not predict one person’s course.

Questions for a clinician

Ask what finding supports the diagnosis, which organs need monitoring, what changes warrant urgent evaluation, and whether genetic counseling or a specialist referral is appropriate.

Research participation

Registries and natural-history studies can help researchers understand variation over time and design better studies. Clinical-trial eligibility depends on the exact diagnosis, variant, symptoms, age, location, and protocol. Participation is always voluntary and a listing is not a recommendation.

Next steps

Learn, connect, and participate

Mitochondrial disease guide

Understand inheritance, symptoms, diagnosis, management, and research.

Read the guide

Patient registry

Learn what participation means and how consent and privacy work.

Registry information

Clinical trials

Browse a source-linked directory and verify current study status.

Browse trials

Research hub

Follow therapies, mechanisms, publications, and funded work.

Explore research

Community support

Find practical resources, events, caregiver paths, and participation boundaries.

Visit community

Single large-scale mtDNA deletion syndromes program

See the MDA program pathway and current planning status.

View program

Sources

References and further reading

  1. MedlinePlus: Mitochondrial Diseases
  2. NINDS: Mitochondrial Disorders
  3. GeneReviews: Primary Mitochondrial Disorders Overview
  4. United Mitochondrial Disease Foundation

External sources are provided for context and do not imply endorsement of MDA.