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.