What is What Is Huntington’s Disease??

An overview of Huntington’s disease, its genetic cause, symptoms, and current treatment options.

Neurology

What Is Huntington’s Disease?

2025-09-27

Intro

Huntington’s disease (HD) is a rare, inherited condition that causes progressive damage to the brain. It affects movement, thinking, and emotions, leading to increasing disability over time.

Key Points

Caused by a genetic mutation in the huntingtin (HTT) gene.
Symptoms usually begin between ages 35–55, though earlier and later onset occur.
Progression continues for 10–25 years after onset.
No cure exists, but medications and therapies can help manage symptoms.
Experimental gene therapy offers new hope.

Background

Huntington’s disease is an autosomal dominant disorder — meaning that inheriting one copy of the faulty gene is enough to cause the disease. Each child of an affected parent has a 50% chance of inheriting the mutation.

Causes or Mechanisms

The HTT gene contains a CAG trinucleotide repeat.
Healthy people have fewer than ~36 repeats.
People with HD have 36+ repeats, and the longer the repeat stretch, the earlier and more severe the disease.
The faulty gene produces a toxic huntingtin protein that damages neurons, especially in the striatum and cortex.

Symptoms

Motor: involuntary movements (chorea), impaired balance, clumsiness.
Cognitive: poor concentration, memory decline, impaired judgment.
Psychiatric: depression, irritability, mood swings.

Diagnosis / Treatment

Diagnosis: based on symptoms, family history, genetic testing, and brain imaging.
Treatment options:
- Medications for movement (e.g., tetrabenazine) and mood disorders.
- Physical and occupational therapy.
- Counseling and psychiatric support.
- Gene therapy (experimental, see Gene Therapy for Huntington’s Disease).

Prognosis

Huntington’s disease is progressive and ultimately fatal, usually within 10–25 years of symptom onset. Treatments can improve quality of life, and research is advancing rapidly toward disease-modifying options.

FAQ

Q: Can Huntington’s disease skip a generation?
A: No. Because it is autosomal dominant, if the gene is not inherited, the disease cannot appear later in that family line.

Q: How common is it?
A: It affects around 3–10 people per 100,000 in Western populations.

Q: Are there lifestyle changes that help?
A: Exercise, physical therapy, and supportive care can help maintain independence longer.