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Living with Hemifacial myohyperplasia

A developmental condition where tissues on one side of the face are enlarged, often the right side.

Understanding Hemifacial myohyperplasia

Hemifacial myohyperplasia is a developmental condition in which tissues on one side of the face grow larger than the other side.

It often affects the right side and is seen more often in males. The enlargement can change the shape of the jaw. Face differences become more noticeable with age and settle at the end of adolescence. Other features can include epilepsy, eye turning (strabismus), and intellectual disability. It starts in the newborn period.

Signs & symptoms

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

  • Enlargement of half of the face
  • Curved wall inside the nose (deviated septum)
  • Dimple in the chin
  • Drooping upper eyelid (ptosis)
  • Narrow opening between the eyelids

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 ear, nose, and throat specialists and genetic specialists.

  3. Consider genetic testing

    Changes in PIK3CA are linked to this condition. Genetic testing and counseling can help confirm a diagnosis and explain what it means for your family.

Care & treatment

Care team
Ear, nose, and throat specialists (otolaryngologists); Genetic specialists (geneticists)
Expert care
Ask about multidisciplinary care centers for rare conditions
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 rare disease patient organizations for support
  • 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
Is genetic testing, such as for PIK3CA, useful for us?
Should seizures or eye problems be watched for?
When should a jaw or facial specialist review growth?

Quick facts

Symptoms usually startNewborn
GenesPIK3CA

GARD says the cause is unknown, though the PIK3CA gene is listed. Theories include hormone imbalance, nerve differences, chromosome differences, and blood or lymph vessel differences.

Genetic

Also known as: hfmh

Patient organizations

Rare-disease groups that can help

Source: NIH GARD · Hemifacial myohyperplasiaGARD ID 10084 · 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 Hemifacial myohyperplasia.

Explore the Hemifacial myohyperplasia blog

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Explore actively recruiting Hemifacial myohyperplasia studies with HealthSpark.

HealthSpark

Find actively recruiting studies for Hemifacial myohyperplasia with HealthSpark. Share your city to explore research near you.

  • Recruiting studies from ClinicalTrials.gov
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  • Eligibility is confirmed by the study team

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

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