OPRM1 and substance withdrawal syndrome: The OPRM1 118A>G AG/GG genotypes have shorter hospital stays for treatment of NOWS than the AA genotype, and mothers with the rs1799971 AG or GG genotype have infants who are less likely to require treatment for NOWS (buprenorphine, MTD), but association with the ABCB1 SNPs and the likelihood of withdrawal syndrome was not significant [74].