Is Parkinson's Disease hereditary?

A fellow caregiver asked...

My Father was diagnosed with Parkinson's about 11 years ago after a bad fall. My Mother had pronounced hand tremors for many years but her doctor was never able to confirm or deny weather she,too, had Parkinson's. Both are gone now. As I approach my 52nd birthday, I am very concerned about my chances of developing this horrible disease. What are my chances of escaping this fate?

Expert Answer

Graham A. Glass, MD, is the co-founder of PEAK Neurology and Sleep Medicine, LLC with multiple locations across Alaska. Previously, he was deputy director of the San Francisco Parkinson's Disease Research, Education, and Clinical Care Center PADRECC and assistant clinical professor of neurology at the University of California, San Francisco (UCSF). Glass received his medical degree from the University of Texas Health Sciences Center at the San Antonio School of Medicine and completed his neurology residency at Tufts-New England Medical Center. He subsequently completed a fellowship in movement disorders at the Mayo Clinic.

The question as to whether Parkinson disease is hereditary is quite complicated. Researchers now think that about 7 or 8 percent of patients with PD have a direct genetic link. This is much more likely to be the case if your parents had onset of Parkinson disease in their 40s or younger. Otherwise it is much less likely. For the remaining people with Parkinson disease, we think that there may be certain genes that put them at an increased risk of developing PD, and that these genes may interact with other genes and environmental factors such as pesticide exposure to result in Parkinson disease. Unless your parents were tested for the specific genes associated with PD, it is virtually impossible to tell you how likely you are to get PD, but genetic cases of PD remain by far in the minority of cases.