People who develop Parkinson's disease before age 50 may have been born with disordered brain cells that went undetected for decades, according to new Cedars-Sinai research. 

Parkinson's occurs when brain neurons that produce dopamine, a substance that helps coordinate muscle movement, become impaired or die. In most cases, the exact cause of neuron failure is unclear, and there is no known cure. 

"Young-onset Parkinson's is especially heartbreaking because it strikes people at the prime of life," says Michele Tagliati, MD, director of the Movement Disorders Program, vice chair of the Department of Neurology, and the Caron and Steven D. Broidy Chair in Movement Disorders.

Published in Nature Medicine, the research focuses on patients between the ages of 21 and 50, who make up just 10% of the 60,000 new patients diagnosed in the U.S. each year. 

The scientists generated unique stem cells—known as induced pluripotent stem cells (iPSCs)—from patients with young-onset Parkinson's, and used the iPSCs to produce dopamine neurons, then cultured them in a dish and analyzed the neurons' functions.

"Our technique gave us a window back in time to see how well the dopamine neurons might have functioned from the very start of a patient's life," says Clive Svendsen, PhD, the leader of the study and director of the Cedars-Sinai Board of Governors Regenerative Medicine Institute, and the Kerry and Simone Vickar Family Foundation Distinguished Chair in Regenerative Medicine.

Key abnormalities were detected that mirror later Parkinson's symptoms. 

"What we are seeing using this new model are the very first signs of young-onset Parkinson's," Svendsen says. 

The iPSC model can also work to test a number of drugs that might reverse the abnormalities they observed. One drug, PEP005, reduced elevated levels of a key protein implicated in the disease, in both the dopamine neurons in the dish and in laboratory mice.

Next, Svendsen and Tagliati says the team plans to investigate how PEP005 might be delivered to the brain to potentially treat or prevent young-onset Parkinson's.