From SNPedia
Variation at this SNP,
rs5751876, also referred to as 1976C>T or 1976T>C, appears to influence how an individual responds to moderate levels (150mg) of
caffeine, with T/T carriers displaying significantly increased subjective levels of anxiety after consumption. [
PMID 12825092] [
PMID 18305461]
rs5751876 is not associated with how much coffee one drinks, though, nor with risk for Parkinson's disease, based on a study of 1,200 subjects.[PMID 18759349]
[PMID 19902562] Purine biosynthetic pathway genes and methotrexate response in rheumatoid arthritis patients among north Indians
[PMID 20334879] Adenosine A(2A) receptor gene: Evidence for association of risk variants with panic disorder and anxious personality