What is young-onset Parkinson’s disease? Most people with Parkinson’s begin to develop movement symptoms after the age of 60. When a person younger than 50 years old is diagnosed with PD, it is called young-onset PD. (Some doctors may refer to young-onset when diagnosed under the age of 40.)
Young-onset PD is unusual, affecting about five to 10 percent of people with PD. That’s about 100,000 people in the United States. Although their symptoms are similar to those of older people with PD, people with young-onset PD often face different financial, family and employment concerns.
Young-onset PD is diagnosed by the same movement symptoms as PD in older individuals:
- tremor of the hands, arms, legs, jaw and face
- rigidity or stiffness of the limbs and trunk
- bradykinesia or slowness of movement
- postural instability or impaired balance and coordination
People with young-onset PD may experience the same nonmotor symptoms as others with PD, including:
- sleep disturbances
- changes in memory and thinking
- constipation or urinary problems
How is Young-Onset Parkinson's Different?
People living with young-onset PD may experience:
- slower progression of PD symptoms
- more side effects from dopaminergic medications
- more frequent dystonias or cramping and abnormal postures, such as arching of the foot
For most people with PD the disease probably is caused by a combination of underlying genetic predisposition and environmental exposures. Genetics plays a larger role in the cause of early-onset PD. Scientists have discovered genes that can cause or increase the risk of early-onset PD. Genetic tests generally are not available, because mutations in these genes occur so rarely, and because treatment is the same as for PD without a known genetic cause.
People who have both early-onset PD and a strong family history of the disease are more likely to carry genes linked to PD, which include:
- Alpha-synuclein (Park1). A rare mutation in one copy of the Alpha-synuclein gene causes early-onset PD
- Parkin (Park2). Inheriting two copies of the mutated Parkin gene causes early-onset PD; inheriting one copy increases the risk
- Pink1. Inheriting two copies of the mutated Parkin gene causes early-onset PD; inheriting one copy increases the risk
- LRRK2. Many different mutations can occur in the LRRK2 gene, which can increase the risk of early-onset PD
The most commonly prescribed drug for Parkinson’s disease is carbidopa/levodopa (Sinemet®). However, people with young-onset PD may be more likely to develop side effects from this medication—dyskinesias, or involuntary movements, at the medicine’s peak effect and dystonia, or cramping, as the effect wears off.
To avoid these side effects, doctors often treat movement symptoms in people newly diagnosed with young-onset PD with other types of medications, including anticholinergics, monoamine oxidase B inhibitors, and dopamine agonists.
Surgical therapy known as deep brain stimulation may be a treatment option for some people who experience severe side effects of carbidopa/levodopa (Sinemet).
The same therapies for nonmotor symptoms are effective both in people with early-onset PD and in those who develop PD at an older age.