AIM:To explore the association between the single nucleotide polymorphisms(SNP)in intron 2of theμopioid receptor gene(OPRM1)and the effective dose in methadone maintenance treatment of heroin addiction.METHODS:The genotypes of the two SNPs(rs9479757,rs2075572)in 68heroin dependent patients in methadone maintenance treatment were detected by TaqMan SNP genotyping technique,and the association between methadone dose and the two SNPs was analyzed.RESULTS:The frequencies of genotype and allele at rs9479757,rs20...