tokens: The rs4704559 G allele was associated with a lower prevalence of dyskinesia ( prevalence ratio ( PR ) = 0 . 615 , 95 % confidence interval ( CI ) 0 . 426 - 0 . 887 , P = 0 . 009 ) and visual hallucinations ( PR = 0 . 515 , 95 % CI 0 . 295 - 0 . 899 , P = 0 . 020 ) .