It seems an amazingly long time or results to get back to you , a whole year!
I understand what you are saying about knowing/not knowing, sometimes it might feel better not to know! But I am surprised that genetics has been mentioned,maybe you are atypical and your neuro can tell from your symptoms because they differ in some way. The 23&me thing is something you can do without ever getting the results if you are so minded. They are aiming for 10,000 pwp's and it is already starting to shed a little light on PD. So it IS worth doing as a contribution even if you do not want to see the results.

Genetic things do not always come out in a family sometimes is is a combination of factors. It is not my thing, so I can't speak scientifically on this, but maybe someone else here knows.

I'm in the UK too, so maybe the year long thing is just part of our much loved but rather slow system of health care.

Lindy