Skip to content
knowrare
HealthSignal
Your condition community

Living with Mitochondrial trifunctional protein deficiency

A rare condition in which the body cannot turn certain fats into energy, especially during fasting, affecting the heart, liver, and muscles.

Understanding Mitochondrial trifunctional protein deficiency

Mitochondrial trifunctional protein deficiency is a rare condition that prevents the body from converting certain fats to energy, especially during fasting.

Signs may begin in infancy or later. In infancy they include feeding difficulties, low energy, low blood sugar, low muscle tone, and liver problems. Infants are also at high risk for serious heart problems and breathing difficulties. After infancy, signs can include low muscle tone, muscle pain, muscle breakdown, and loss of feeling in the arms and legs. Problems can be triggered by fasting or by illnesses such as viral infections.

Signs & symptoms

Symptoms vary from person to person. GARD lists these among the most common:

  • Low muscle tone and muscle weakness
  • Feeding difficulties in infancy
  • Heart muscle disease (cardiomyopathy)
  • Liver problems
  • Muscle breakdown (rhabdomyolysis)
  • Nerve damage in the arms and legs (peripheral neuropathy)

Not everyone has every symptom. GARD's list comes from the Human Phenotype Ontology.

Diagnosis

  1. Talk with your doctor

    Share the symptoms you've noticed, when they started and your family health history. Notes and photos can help.

  2. See a specialist

    Specialists who may be involved include brain and nervous system specialists, genetic specialists and heart and blood vessel specialists.

  3. Ask which tests can help

    Your care team will decide which exams and tests can confirm the diagnosis.

  4. Connect with expert centers

    Children's Cardiomyopathy Foundation, United Mitochondrial Disease Foundation and MitoAction may keep lists of experts for this condition.

Care & treatment

Care team
Brain and nervous system specialists (neurologists); Genetic specialists (geneticists); Heart and blood vessel specialists (cardiologists)
Expert care
Expert lists: Children's Cardiomyopathy Foundation, United Mitochondrial Disease Foundation, MitoAction
Treatment
GARD doesn't list specific treatments for this condition. Your care team will tailor care to your symptoms.
Research
Clinical trials and observational studies may be options. See the research section below.

General information, not medical advice. Your care team makes the decisions.

Everyday life

Living with a rare condition is easier with support.

  • Connect with FOD (Fatty Oxidation Disorder) Family Support Group and other patient organizations
  • Keep notes on symptoms, changes and questions for appointments
  • Ask about patient registries that help research
  • Look into financial aid and travel resources for care visits
Bring these questions to your next doctor visit
Can genetic testing confirm the diagnosis?
How should we plan for illness and periods without food?
Which specialists, such as for the heart, liver, and metabolism, should be involved?

Quick facts

Symptoms usually startNewborn and as an Infant
InheritanceAutosomal Recessive, Mitochondrial

Changes in genes (also called variants) cause this condition. GARD lists autosomal recessive and mitochondrial inheritance but does not name a gene in this record.

GeneticNeurologicalInherited MetabolicMitochondrial

Also known as: human trifunctional protein deficiency; tfp deficiency; tfpd; trifunctional enzyme deficiency; trifunctional protein deficiency

Patient organizations

Source: NIH GARD · Mitochondrial trifunctional protein deficiencyGARD ID 3684 · GARD page updated September 2026 · Plain-language summary by Know Rare; editorial review pending. General information, not medical advice.

You are more than your diagnosis

Perspectives from people navigating life with Mitochondrial trifunctional protein deficiency.

Explore the Mitochondrial trifunctional protein deficiency blog

Explore research for Mitochondrial trifunctional protein deficiency

Explore actively recruiting Mitochondrial trifunctional protein deficiency studies with HealthSpark.

HealthSpark

Find actively recruiting studies for Mitochondrial trifunctional protein deficiency with HealthSpark. Share your city to explore research near you.

  • Recruiting studies from ClinicalTrials.gov
  • Share your city to look for research near you
  • Eligibility is confirmed by the study team

Powered by HealthSpark, our AI chat helper

I can help you find recruiting Mitochondrial trifunctional protein deficiency studies. Enter a ZIP code, address or city below and I'll look within 50 miles.

Powered by HealthSpark, our AI chat helper · Study information from ClinicalTrials.gov · Eligibility is confirmed by the study team.

Get Signals for Mitochondrial trifunctional protein deficiency

Stay in the loop with community stories and updates from medical researchers.

HealthStoryfor Mitochondrial trifunctional protein deficiency

Create a living journal that talks back

HealthStory evolves private journaling with a living AI journal that talks back and asks thoughtful questions, helping you capture your Mitochondrial trifunctional protein deficiency experiences more deeply and prepare for better conversations with your doctors and care team.

Start your journal

Your journal is private. Sharing your story publicly is a separate choice, made with Share your story above.