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PubMed This is a summary of 63 peer-reviewed journal articles Updated
Medical Genetics

Hemifacial Hyperplasia: A Guide for Patients and Families

At a Glance

Hemifacial Hyperplasia (HFH) is a rare congenital condition causing overgrowth on one side of the face, typically driven by a PIK3CA gene mutation. Care involves a specialized team, carefully timed surgeries, and emerging targeted therapies like PI3K inhibitors.

Receiving a diagnosis of Hemifacial Hyperplasia (HFH)—or navigating life with it—can feel overwhelming. Because it is a rare condition, finding clear, accurate, and practical information can be a challenge. This guide was created to empower you with evidence-based knowledge so you can advocate for yourself or your child.

Hemifacial Hyperplasia is a congenital overgrowth disorder that affects one side of the face. It is often linked to a genetic mutation in the PIK3CA gene, placing it on the PIK3CA-Related Overgrowth Spectrum (PROS). While the journey involves navigating complex medical decisions, you are not alone, and treatments are advancing rapidly.

Explore the sections below to understand the condition, build your medical team, and plan for the future:

01

Understanding Hemifacial Hyperplasia

Learn about hemifacial hyperplasia (HFH), a condition where one side of the face grows larger. Understand its link to PROS, growth stages, and treatments.

02

Signs, Symptoms, and Subtypes of Hemifacial Hyperplasia

Learn about the signs, symptoms, and subtypes of Hemifacial Hyperplasia (HFH), including CIL-F. Understand how facial overgrowth affects teeth, jaws, and TMJ.

03

The Biology and Genetics of Hemifacial Hyperplasia

Learn about the genetics of Hemifacial Hyperplasia (HFH). Understand somatic mosaicism, PIK3CA mutations, the PROS spectrum, and why HFH is not cancer.

04

Diagnosis and Building Your Care Team

Learn how Hemifacial Hyperplasia (HFH) is diagnosed using 3D imaging and tissue biopsy. Discover how to build a specialized multidisciplinary care team.

05

Treatment Options and Timing

Learn about treatment options for Hemifacial Hyperplasia (HFH). Understand the timing of jaw surgery, soft tissue debulking, and new targeted therapies.

06

Long-Term Outlook and Monitoring

Learn about the long-term outlook for Hemifacial Hyperplasia (HFH). Understand adult monitoring for TMJ, sleep apnea, and why tumor screening may change.

Common questions in this guide

What is Hemifacial Hyperplasia (HFH)?
Hemifacial Hyperplasia is a rare congenital disorder that causes excessive growth of hard and soft tissues on one side of the face. It can affect facial structure, dental health, the airway, and the jaw joint.
What causes Hemifacial Hyperplasia?
HFH is typically caused by a somatic mutation in the PIK3CA gene that occurs randomly after conception. This mutation alters the PI3K/AKT/mTOR pathway, causing irregular cellular growth signals in the affected facial tissues.
Is Hemifacial Hyperplasia a type of cancer?
No, Hemifacial Hyperplasia is not cancer. While it involves cellular overgrowth and shares genetic pathways with some cancers, the condition is fundamentally different and does not spread like a malignancy.
Why don't standard blood tests detect Hemifacial Hyperplasia?
Diagnosis is confirmed through clinical evaluation, specialized imaging, and genetic testing of the affected tissue itself. Standard genetic blood tests often fail to detect the mutation because it is typically only present in the overgrown facial tissue.
What are the treatment options for Hemifacial Hyperplasia?
Treatment is highly personalized and may include carefully timed surgeries to address bone and soft tissue overgrowth. Recently, targeted medical therapies like PI3K inhibitors have also emerged as a way to treat the underlying genetic cause.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Given our specific diagnosis, which sections of this guide are most critical for us to focus on right now?
  2. 2.Are there local specialists you recommend who have experience with the PIK3CA-Related Overgrowth Spectrum (PROS)?
  3. 3.How do you stay updated on the rapidly evolving guidelines for PROS and Hemifacial Hyperplasia?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

This guide provides general educational information about Hemifacial Hyperplasia and the PROS spectrum. It is not a substitute for professional medical advice, diagnosis, or treatment from your specialized healthcare team.

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