Huntington’s Disease (HD) is a hereditary neurological disorder of the central nervous system that causes progressive degeneration of cells in the brain. This degeneration causes the affected person to slowly loose the ability to move, communicate and think. People are born with this disease, but won’t develop symptoms until between the ages of 30 – 50. Although Huntington’s disease can be traced back to the Middle Ages, it was first described by American physician George Huntington in 1872 in his only written article called “on Chorea.”
HD is caused by a defect on chromosome 4. The defect causes a part of DNA, called a CAG repeat, about 30 to 120 times more than it is supposed to. Normally it should repeat 10 to 28 times. As the gene is passed down through generations the number of repeats tend to get larger. The increased repeats means that the symptoms will develop at younger ages throughout generations. The earlier the symptoms appear the faster the disease will progress.
Early signs of HD include slight, uncontrollable muscular movements, stumbling, memory problems and change in mood. Personality changes can occur up to 10 years before abnormal movements can be noticed. Main symptoms include:
Movement disorders – movements can involve all four limbs and the trunk. Also movements of the face and head can occur.
Eye movement – difficulty looking sideways and they will have to move their head to achieve full lateral vision.
Parkinsonism – symptoms similar to Parkinson’s Disease with slowness of movement and increased muscle tone
Memory and other neurological – forgetfulness, thinking and thought process will be slower.
Behavioral – depression, sleeping difficulty, loss of appetite and weight, schizophrenia, etc. and behavioral symptoms can increase with stress
Death usually occurs 15 to 20 years after the initial symptoms as a result of secondary illnesses.
Huntington’s Disease can be diagnosed by a blood test to detect