Is parkinson disease hereditary and are there any tests you could have to see if you have it or are more likely to get it that the average person? Would the doctor turn away a 23 year old and tell them to come back in like 40 years?
It seems to be unclear as to whether Parkinson's is hereditary or not.
There's no test for it & diagnosis is made by a neurologist after observation & medical history over a period of time.
If you are worried see your GP.
Strangely enough Parkinsons disease is caused by a lack of dopamine in the brain whereas too much dopamine is associated with Schrizophrenia. This is a chemical in the brain related to nerve transmission.
Early Onset Parkinsons (especially a 23 yr old) is VERY rare. However, I'm sure if you felt you had any symptoms, the doctor wouldn't just dismiss you without tests.