Thanks for highlighting this Laura.
Apart from giving my sample to 23andme and completing a number of their surveys, I've not looked at the genetic side of PD.
I'm struggling to understand the meaning of the PD meta-analysis table http://www.ncbi.nlm.nih.gov/pmc/arti...-1002548-t002/
So, I'll be grateful if someone would correct my errors as I walk through the first row (GBA) of the table.
Locus/Polymorphism/Location: homes into the location of the genetic difference.
Allele contrast: the actual difference: G where an A would usually be.
MAF = minor allele frequency: 0.01. 1% of people have a G.
N datasets: the number of studies making up the meta-analysis.
N samples: the number of people sampled: 44851
OR: odds ratio: 3.51. A person with this allele is more than 3 times as likely as the average person to get PD.
What I find interesting is the information content in the the knowlege that one has a G rather than an A.
An odds ratio of 3.51 sounds high, but given that on average only 1.6% of people get PD (23andme figure), this equates to a probability of getting PD of 5.6% for people with this mutation.
Or, put another way, given the frequency of 0.01 for this mutation it explains 0.01*0.056*100/1.6 = 0.035% of all PD cases.
This is only one mutation, and others will cumulatively explain more. But it suggests to me that genetics on its own do not explain the aetiology of PD. Genetics are useful, but environment/infection/lifestyle are the key.
Have I got this right?