Genetic Causes of Parkinsons Disease

A person’s genetic make up can directly determine chances of the onset and development of Parkinsons. Current research suggests that people with a family history of Parkinsons are more likely to develop Parkinsons themselves. It is rare however, for multiple people in a family to suffer from Parkinsons.

For example, if you have two or more close relatives (parent, child, or sibling, etc) with Parkinson’s, then your risk of also developing the disease is increased two or three times. Even at this elevated level of risk, though, the overall chance of developing the disease during your life is still less than 5 percent. So while there seems to be a genetic link for Parkinsons Disease, this appears to be a minor link in most cases.

In order to learn about Parkinsons, research has concentrated on rare family groups where multiple people have developed Parkinson’s, and the results have provided useful insights into the cause of the disease in general.
Researchers have determined there are two categories of genetic causes in families with Parkinson’s:

    High Levels of Specific Proteins

    Abnormally high levels of alpha-synuclein, a unique protein that accumulates in degenerating brain neurons of those with Parkinson’s. Other known genes include DJ-1, PINK-1, and UCHL-1, but altogether these represent far less than 1% of Parkinson’s cases.

    Problems with Disposing on Unwanted Proteins

    Problems with the systems in the body that dispose of unwanted proteins. The most important is a gene called parkin, which creates a protein, also called parkin. This protein helps to break down defective proteins inside brain cells (neurons).

    When the parkin gene is altered, or mutated, this function is impaired, and this may lead tyo the accumulation of defective proteins that contribute to death of neurons. Two mutated copies of the parkin gene are needed to develop Parkinson’s. This type of inheritance pattern is called autosomal recessive. One copy of the defective gene is inherited from each parent. Parkin mutations are believed to cause young-onset PD, with symptoms beginning usually in the 40s. Parkin mutations are the most common genetic cause of Parkinson’s, but they still account for less than 1% of all Parkinson’s cases.

It is believed that both of these factors play a key role in the development of Parkinson’s in all people, but further research is required.

Researchers have also found a variation in the CYP2D6 gene that appears to make people more likely to develop Parkinson’s if they are exposed to certain pesticides.