Cause of Huntington's Disease

The cause of Huntington's disease is a defect in a gene on chromosome number 4. This gene, known as the HD gene or Huntington disease gene, is responsible for creating a protein called huntingtin. When a defect occurs in the HD gene, the body creates an abnormal huntingtin protein, which disrupts the normal function of certain nerve cells, ultimately leading to their premature death. The cause of Huntington's disease symptoms is a result of this dysfunction and loss of nerve cells.

 

What Is the Cause of Huntington's Disease?

Huntington's disease (also known as Huntington disease or HD) is caused by a defect in a gene on chromosome number 4. This gene is known as the Huntington disease gene or HD gene.
 

Understanding the HD Gene and Huntington's Disease

The HD gene makes a protein called huntingtin. The function of this protein is unknown, but it most likely plays an important role in nerve cells. When a defect occurs in the HD gene, it leads to the body creating an abnormal huntingtin protein. This abnormal protein disrupts the normal function of certain nerve cells and ultimately leads to their premature death. The signs and symptoms of Huntington disease are caused by this dysfunction and loss of nerve cells.
 
The area of the brain most affected by an abnormal Huntington disease gene is the basal ganglia, which coordinates movement. This degeneration from the Huntington's disease gene causes uncontrolled movements, loss of intellectual faculties, and emotional disturbance. Also affected is the brain's outer surface, or cortex, which controls thought, perception, and memory.
 
(Click Inheriting Huntington's Disease to learn how someone inherits the Huntington disease gene mutation.)
 
Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD