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. The research points to a drug that potentially might help correct these disease processes. Parkinson’s occurs when brain neurons that make dopamine, a substance that helps coordinate muscle movement, become impaired or die. Symptoms, which get worse over time, include slowness of movement, rigid muscles, tremors and loss of balance. In most cases, the exact cause of neuron failure is unclear, and there is no known cure. At least 500,000 people in the U.S. are diagnosed with Parkinson’s each year, and the incidence is rising. Although most patients are 60 or older when they are diagnosed, about 10 percent are between 21 and 50 years old. The new study, published in the journal Nature Medicine, focuses on these young-onset patients.