Normal allele: CC
A polymorphism in the NMDA glutamate ionotropic receptor type 2A subunit 2A (GRIN2A) gene causes at least a 5-fold higher risk of Parkinson's disease when interacting with caffeine.
Polymorphism rs4998386 is related to topics like this:
Research and publications:
26942037 Genetic profile, environmental exposures and their interactions in Parkinson's disease.