I checked back with the 23 and me site. I found they had new data on the PD area of my sample. It listed the LRRK2 gene and the SNP rs34637584
with a genotype of GG. Can you tell me if this means my PD is likely genetic? My grandmother is from Lebanon. It also says that persons of Middle Eastern descent are 40% more prevalent. Or does this mean that is the area on the gene that they tested the rs34637584 and the corresponding genotype of GG is negative?

Technical Report
Gene or region: LRRK2
SNP: rs34637584
SNP used Genotype Adjusted Odds Ratio*
Jim S rs34637584 GG European: 0.98
Asian: NA (not applicable)

* Odds ratios are reported for all available ethnicities.

Mutations in the LRRK2 gene are one of the most common known genetic causes of Parkinson's disease (PD).

More than 50 variants are known in the LRRK2 gene. Several of these have been associated with PD. This variant reported by 23andMe, rs34637584, also known as the G2019S mutation, is the best-studied LRRK2 SNP related to Parkinson's in individuals with European ancestry.

Parkinson's is a fairly rare disease. The average person has a 1-2% chance of developing the disease during his or her lifetime. The chance that a person with the G2019S mutation will develop Parkinson's is much higher than average and increases with age. One recent study found that people who carry the G2019S mutation have a 28% chance of developing Parkinson's by the age of 59, 51% by the age of 69 and 74% by the age of 79. However, estimates of PD risk due to the G2019S mutation vary greatly. While it is well established that the mutation's effect is very strong, there is no consensus about its exact magnitude.

Of all people with Parkinson's, few have the G2019S mutation, but it is present at high levels in patients from some ethnic groups. Up to 40% of people with PD who are of Arab-Berber ancestry and 20% of Ashkenazi Jewish people with PD have this mutation.

Scientists do not know why only some people with the G2019S mutation get PD. There may be unknown effects due to other genes or environmental factors.