Does Parkinson's Disease have a genetic component that can be inherited?

My husband father died from Parkinson's disease complications, his aunt was recently diagnosed with it as well. My husband is in his early 40's and I have seen that he is changing words in his speech very often. He is trying to mean something, and uses the wrong word. Is there any specific test that can make an early detection of Parkinson's disease? Should him seen a neurologists? Or (as he says, is just that he is "very tired")