DRD2 and alcohol abuse: In one, example, assessing the DRD2 A1 allele, we found that while screened controls (eliminating drug and alcohol abuse) in over 3,000 subjects showed a prevalence of approximately 26 %; when we eliminated all RDS behaviors in the probands and family surprisingly we found the DRD2 A1 allele prevalence to be only 3 % [19].