Study On Side Effects of Parkinson's Medication

23andMe posted information on a new genetic study that may help those looking for ways to avert some of the troubling side effects of a common medication used to treat Parkinson’s disease.

Parkinson’s is sometimes treated with medication that increases dopamine activity in the brain. In some patients, that triggers impulsivity, such as compulsive gambling, shopping, eating, or hyper-sexuality.

The study is titled: “Genetic prediction of impulse control disorders in Parkinson’s disease”. It was posted in Wiley Online Library. The object of the study was to develop a clinico-genetic predictor of impulse control disorder (ICD) risk in Parkinson’s disease (PD).

The research was supported by the NIH, a Biomarkers Across Neurodegenerative Diseases (BAND) grant from the Michael J. Fox Foundation/ Alzheimer’s Association/ Weston Institute, The Penn Center for Precision Medicine, and a Copp Foundation grant.

The summary of the research stated: “In summary, we present our findings from a study of 5779 PD individuals from the UPenn, PPMI, and 23andMe cohorts, demonstrating that an ICD risk predictor composed of seven easily obtained clinical variables and genotype at two SNPs can identify PD individuals at extremes of risk for IDC development. 

“Our finding have clinical implications for pharmaogenetic decision making in PD: identification of high-ICD-risk individuals may allow for avoidance of DA use in this group, sparing them considerable ICD-related morbidity. More generally, the development of molecular tools, such as the IDC-RS reported here, may permit a new “precision medicine” approach to the care of patients with neurodegenerative disease.”

23andMe reported that researchers have identified genetic variants in Parkinson’s patients at risk for that problem. Using genetic modeling could help identify patients who are more likely to develop impulse control disorder due to prescribed dopaminergic medications.

Using machine learning and statistical techniques, the team was able to create a risk model to identify those at the highest risk.

In the paper, the researchers suggest that this might ultimately be used to make it easier for physicians treating those with Parkinson’s disease to identify those that should be prescribed an alternative to medication that increases dopamine activity, like levodopa.

The study used data from about 5,700 individuals with Parkinson’s disease. Most of the data came from 23andMe Parkinson’s research participants who consented to participate, with the remainder coming from two other research cohorts, one at the university of Pennsylvania and the other at the Parkinson’s Progression Markers Initiative.

The research involved two major steps. The first looked at genetic variants associated with impulse control disorder in people with Parkinson’s. Once they identified these variants, researchers used machine learning and statistical techniques to create a risk model. This helped them identify individuals who were more likely to develop impulse control disorder if the prescribed medication that affected the dopamine activity in their brain.

In evaluating the model, the researchers said it performed better than similar pharmacogenetics models already used in prescribing anti-platelet drugs.

While dopaminergic drugs are very important and effective in treating motor control issues in Parkinson’s patients, impulse control disorder side effects are relatively common. In this study, n 20-30 percent of those treated with dopaminergic drugs experienced impulse control disorder.

Applying this pharmacogenetic approach could be effective at identifying those individual better served by the use of an alternative to dopaminergic medications. One of those alternatives include the drug levodopa, the researchers said.

Related Articles on FamilyTree.com:

Parkinson Foundation Expands Free At-Home Genetic Testing

Researchers Seek Genetic Cause of Parkinson’s

Study About Parkinson’s Includes Data from 23andMe

< Return To Blog