Huntingtons Disease Symptoms

The symptoms of Huntington’s disease profoundly affect the lives of patients and their families. HD interrupts a person’s ability to walk, think, and communicate. Over time, a person with the symptoms of Huntington’s disease becomes completely dependent on others for care. These symptoms take a toll on entire families emotionally, socially and economically.

The age of onset and the severity of symptoms of Huntington’s disease are directly related to the number of repeat expansions that show up in a person’s DNA sequence as a result of a mutation in the person’s inherited huntingtin gene.

The Age of Onset of Symptoms of Huntington’s Disease

Healthy people have 9 to 39 repeats of the DNA sequence, but patients with the mutated huntingtin gene have between 36 and 121 repeats of the sequence. The number of repeats is inversely related to the age of onset of the symptoms of Huntington’s disease. This means that the larger the number of repeats, the younger a patient will be at the onset of the disease. People who have 36 to 41 repeats may never show any symptoms of Huntington’s disease. People with over 50 repeats usually show symptoms of Huntington’s disease before they are 20 years old. The mean age of onset is between 35 and 44 years of age.

The Severity of Symptoms and Huntington’s Chorea

The severity of the symptoms of Huntington’s disease is also directly related to the number of repeats in the DNA sequence. Patients with only a few additional repeats may only develop mild symptoms late in life. Patients with many additional repeats may strongly exhibit the symptoms of Huntington’s disease.

The result is a loss of neurons in the brain. This neuron loss can cause some of the following symptoms:

  • abnormal facial movements
  • abnormal body movements
  • mood swings
  • depression
  • irritability
  • jaw clenching (bruxism)
  • slurred speech
  • difficulty walking
  • personality changes
  • loss of mental capacity (dementia).

The abnormal facial and body movements are often described as uncontrollable dance-like, quick jerking movements. These movements are sometimes referred to as Huntington’s chorea because “chorea” means dance.

All of these symptoms of Huntington’s disease become more severe over time as the cells in the brain continue to die. Sometime within fifteen to twenty years of the onset of the symptoms of Huntington’s disease, the patient dies. Death is usually due to infection. Sadly, suicide is also a common cause of death, due to the suffering related to the heartbreaking symptoms of Huntington’s disease.


Bossy-Wetzel, E., Schwarzenbacher, R., Lipton, S.A. (2004). Molecular pathways to neurodegeneration. Nature Medicine 10 (Supplement), S2-9.

Dolan DNA Learning Center. (nd). What is Huntington disease?

Neurology Channel. (2004). Huntington’s disease.