PATHOLOGY

Detailed explanation-1: -Mutations in the HTT gene cause Huntington disease. The HTT gene provides instructions for making a protein called huntingtin.

Detailed explanation-2: -Normal Function The HTT gene provides instructions for making a protein called huntingtin. Although the exact function of this protein is unknown, it appears to play an important role in nerve cells (neurons) in the brain and is essential for normal development before birth.

Detailed explanation-3: -Huntington’s disease is caused by a faulty gene. Cells in parts of the brain are very sensitive to the effects of the faulty gene. This makes them function poorly and eventually die. A parent with the Huntington’s disease gene has one good copy of the gene and one faulty copy.

Detailed explanation-4: -HD is caused by mutation in a gene located on chromosome 4. This gene is found in every human being, and contains a CAG repeat sequence. We have not yet discovered the gene’s normal function. In a case of HD, the gene contains an abnormally large number of CAG repeats.