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Mitochondrial Complex Iii Deficiency Nuclear Type 5 C3554608

Published: July 22, 2026Updated: August 20, 2026

A rare genetic condition that impairs the mitochondria's ability to generate energy in cells. Typically presents in infancy or early childhood. Management involves symptom control and metabolic support.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 20, 2026Editorial policy

Key facts at a glance

ICD-10
E88.9
ICD-11
5A00.0
Body system
metabolic
Severity
severe
Chronic
true

Signs and symptoms

Common signs and symptoms that may indicate this condition.

Warning signs - seek immediate care

!

Encephalopathy

Fatigue or weight changes

(metabolic)

Significant symptoms that substantially affect daily functioning.

Frequency: Common at all stages

Muscle fatigue

(musculoskeletal)

Intermittent hypoglycemia

(metabolic)

Hepatic dysfunction

(hepatobiliary)

Diagnosis and tests

How this condition is diagnosed and what test results mean.

Initial screening tests

1

Standard diagnostic workup

Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]

Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]

Treatment options

Evidence-based approaches to managing this condition.

First-line treatments

1

Exercise Tolerance Testing

Serial cardiopulmonary exercise testing to objectively assess functional capacity, monitor disease progression, and guide activity recommendations.

monitoring
2

Pharmacological management with first-line agents

Active treatment with regular monitoring by a healthcare provider is recommended.

medication
3

Idebenone Therapy

Administration of idebenone, a synthetic analog of CoQ10, to bypass complex III deficiency and support mitochondrial electron transfer.

medication

Additional treatment options

Glycemic-Sensitive Meal Planning

Implementation of dietary strategies emphasizing complex carbohydrates and glycemic control to minimize metabolic stress and lactate production.

dietary

Cardiac Device Implantation

Pacemaker or defibrillator placement for patients with complex III-related cardiac conduction abnormalities or arrhythmia.

surgical

Interval Training Protocol

Supervised interval training combining short periods of activity with rest periods to maintain cardiovascular fitness while avoiding metabolic exhaustion.

physical_therapy

When to seek medical help

Recognize when you need immediate medical attention.

See a doctor within 24 hours

Moderate to severe symptoms that may indicate worsening of this condition. Prompt medical evaluation is recommended.

Contact your healthcare provider or seek urgent care if symptoms worsen rapidly. Go to the emergency department for life-threatening symptoms.

Frequently asked questions

Common questions about this topic.

Q

What is Mitochondrial Complex Iii Deficiency Nuclear Type 5 C3554608?

Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]

general

Medication Comparisons

Compare medications used to treat Mitochondrial Complex Iii Deficiency Nuclear Type 5 C3554608. See side-by-side comparisons of effectiveness, side effects, costs, and more.

View Medication Comparisons

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy