Parkinson's disease is a progressive neurodegenerative disorder that affects movement control. Symptoms include tremors, stiffness, and difficulty in balance and coordination. Treatment includes medications to manage symptoms, physical therapy, and, in some cases, surgeries such as deep brain stimulation. The assessment of the Polygenic Risk Score for Parkinson's disease is based on examining 24 gene polymorphisms.
Genetic testing for Parkinson's disease is included along with 15 other diseases in the Genetic Screening for Diseases of the Nervous System, Polygenic Risk Score.
Causes and non-genetic risk factors
Parkinson's disease occurs when nerve cells or neurons in the basal ganglia, the area of the brain that controls movement, wear out and/or die. These neurons produce dopamine, so destroying them involves producing less dopamine, which causes motor problems. However, the exact cause of the degeneration of these neurons is currently unknown. Some cases of Parkinson's disease appear to be hereditary and can be attributed to specific genetic changes. However, they may result from genetic changes and environmental factors.
In addition to genetic predisposition, the following risk factors have been described:
- Gender: men are more likely to develop Parkinson's disease.
- Age: most people with Parkinson's develop the disease for the first time around age 60, and the risks increase with age. However, 5-10% have an "early-onset" disease that starts before age 50.
- Exposure to toxins. Continued exposure to herbicides and pesticides may slightly increase the risk of Parkinson's disease.
Symptoms
The signs and symptoms of Parkinson's disease can vary between individuals. Early signs can be mild and go unnoticed. The rate of progression varies between patients, and even the initial symptoms are characterized as those of aging. Often, symptoms start on one side of the body and continue to worsen on that side even when symptoms begin to affect both sides. The symptoms most often associated with this disease are:
- Tremor in the hands, arms, legs, jaw, or head.
- Stiffness of the limbs and trunk.
- Slowing down movement.
- Disturbance of balance and coordination, sometimes leading to falls.
Patients with Parkinson's disease often develop a Parkinsonian gait that includes a tendency to lean forward, small rapid steps as if rushing forward, and decreased hand swing. They may also have trouble starting or continuing movement. Other symptoms may include depression and other emotional changes, difficulty swallowing, chewing, and speaking, problems urinating or constipation, skin problems, and sleep disturbances.
Prevention
Some cases of Parkinson's disease are inherited and may be caused by genetic changes, but in many cases, the disease is sporadic (not hereditary). Because the precise cause of Parkinson's disease is unknown, proven ways to prevent it are also limited. Some research has shown that regular physical activity can reduce the risk of developing Parkinson's disease. Other studies show that caffeine consumption from coffee, tea, or colas is associated with a lower risk. However, insufficient evidence suggests that caffeinated beverage consumption has a protective effect against Parkinson's disease.
