Parkinson’s Awareness Month: How Genetic Testing is Changing Treatment for Parkinson’s

April is Parkinson’s Awareness Month, a good time to talk about how genetic testing is rapidly changing how we treat certain disorders and diseases, including Parkinson’s disease (PD).

Genetic testing is resulting in more precise, effective trials and treatment since new therapies are regularly being developed for certain genetic changes associated with PD, says Vanessa Hinson, M.D., Ph.D., director of MUSC Health’s Movement Disorders Program, which is involved in ongoing research and clinical trials to find new and better ways to treat patients with PD and other movement disorders. “It’s really taking off because knowledge of the role of genetics in PD has grown so quickly.”

Genetic Testing & Parkinson’s

Genetic testing can help flag any genetic mutations, or defects, that may be linked to Parkinson’s, and this information can help researchers more accurately match patients with treatments and clinical trials.

“Genes affect why you have Parkinson’s; at-risk genes play a role. You have to have a predisposition that makes you vulnerable to getting the disease,” says Dr. Hinson, noting the medical community assumed for decades that PD was largely not genetic because it can skip generations. Since researchers identified the first gene associated with PD about 20 years ago, genetic testing has now identified many genes that contribute to the disease.

What Genetic Markers Tell Us

While some genetic markers can lead directly to disease, most genetic variations associated with Parkinson's do not carry a 100-percent guarantee of getting it. In fact, they increase the risk by just a small amount. Only about 10 to 15 percent of people with PD have a straightforward genetic cause for developing the disease. The other 85 to 90 percent have one of several identified at-risk genes. The most common of these is a mutation in the GBA gene.

How Genetic Testing is Shaping Parkinson’s Treatment

In the future, treatments will differ depending on the cause, though the symptoms might be similar, says Dr. Hinson. New potential treatments based on genetic research would tailor therapies specifically to what’s going on in an individual’s brain.

In people with the GBA mutation, for instance, the brain is not producing enough of a certain digestive enzyme. “The part of the brain that is like a garbage disposal system that gets rid of toxic materials, is malfunctioning in these people and the brain cannot rid itself of toxic substances,” says Dr. Hinson.

A Parkinson’s Clinical Trial

In the MOVES-PD clinical trial, participants with the GBA mutation are prescribed medicine that aims at increasing that enzyme, allowing the brain to handle toxic waste more efficiently and to counteract the GBA gene. This is the first trial of its kind to target a specific group of people with PD defined by a genetic mutation.

Participants must know which PD gene they have before they can start one of the new gene-specific trials at MUSC or elsewhere. “Knowing about PD mutations allows us to be specific in pointing patients to certain trials,” says Dr. Hinson. It’s also why early diagnosis is so important. “It allows us to recommend the right clinical trial for a patient and to get on top of PD when it’s in the early stages and easier to manage, before it gallops away and really progresses.”

The MUSC Movement Disorders Program

As a Parkinson's Foundation Center of Excellence, MUSC Health offers people with Parkinson’s the opportunity to participate in national clinical trials. In the Movement Disorders program, the only comprehensive movement disorders program in the state, patients receive a comprehensive evaluation from a team of professionals in a single, coordinated appointment in the unique interdisciplinary clinic.

“All in one appointment, you will see every single interdisciplinary team member, and leave with a treatment plan that addresses PD from all angles,” says Dr. Hinson. Neurologists and specialty staff, including physical therapists and psychiatrists with specific expertise in movement disorders, coordinate services targeted to each patient’s needs.

The program also has a genetic counselor on staff. “Most patients with PD want to know what it means for them, for their families, will they pass it on, what are their risks,” says Dr. Hinson. “As a Center of Excellence, we’re set up to help patients understand and share that information.”

Dr. Hinson advises patients with or at risk for Parkinson’s to be evaluated not just by a neurologist, but also by a movement disorder specialist. “Parkinson’s causes tremors, affects walking and also can affect blood pressure, mood, gut and cognition,” she says.

A movement disorder center is important for patients to seek out, she says, because such centers treat the entire person. They also evaluate patients for research candidacy. “This is very important with a disorder for which there is not yet a cure,” she notes.

To learn more about the Movement Disorders Program available at MUSC Health or to schedule an appointment, please call 843-792-3223. MUSC is the only medical center in South Carolina that offers people with movement disorders the opportunity to participate in clinical trials. By enrolling in a clinical trial, you may be able to try new therapies designed to slow or stop disease progression or improve symptoms. You do not have to be a patient at MUSC Health to participate.