9.1.6) Parkinson’s

Your normal risk of developing Parkinson’s disease

Parkinson’s disease is a progressive disorder of the nervous system that affects movement and motor skills. It develops slowly over time and usually begins with a small tremor, stiffness and a slowing of movement. Sensory and sleep difficulties are also common symptoms and can often prelude the signs of tremors.

In Parkinson’s, certain neurons (nerve cells) in the brain begin to break down and die. The cause of the disease is still unknown, but researchers have identified both genetic and environmental factors that play a role.  

We report on two of the most commonly studied genetic variations related to the development of Parkinson’s Disease. There are other genetic risk factors being studied that may become important indicators in the future.

Prevalence: There are approximately 4 million people worldwide who have been diagnosed with the disease and about 60,000 diagnosed each year in the United States. The disease affects people of all races but is slightly more common in Caucasians and in men. Majority of people are diagnosed at age 60 and over.

Symptoms: Early signs are often mild and sometimes unnoticeable. A tremor may affect one side of the body and slowly get worse over time. Other symptoms include slowed movement, muscle stiffness and a change in speech and involuntary movement.

Diagnosis: There is no specific test to diagnose Parkinson’s disease. A neurologist will diagnose Parkinson’s disease based on medical history, a review of signs and symptoms, and a neurological and physical examination. They will also rule out other diseases and conditions through other testing.

Treatment: Genetic approaches to therapies are being provided, such as reducing and clearing alpha-synuclein and inhibiting LRRK2 kinase activity. Pharmaceutical companies have active programs aimed at targeting LRRK2 kinase activity. Increasingly, links to diet are being identified and explored.

Some examples of genes that have been associated with the risk of developing Parkinson’s disease are:

GBA: Encodes an enzyme known as acid beta-glucocerebrosidase or beta-glucosidase, a lysosomal enzyme that catalyzes the breakdown of a fatty waste product called glucocerebroside. 

LRRK2: Encodes the leucine-rich repeat kinase 2 protein. Variation is associated with lysosomal function and neuronal health.