A rapid screening method for a single nucleotide polymorphism (SNP) in the human MOR gene

Abstract

Aims Genetic association studies have suggested that the single nucleotide polymorphism (SNP) at position 118 of the human m-opioid receptor (MOR) gene could be a potential risk factor for drug treatment variability in patients. Therefore, we wanted to develop a fast and reliable detection method for this SNP which is applicable in a clinical setting. Methods To detect the polymorphism at position A118pG in the human MOR gene we used the¯uorescence resonance energy transfer (FRET)-PCR technique with subsequent melting curve analysis.Results The polymorphism at position A118pG in the human MOR gene could be clearly discriminated with melting peak temperatures of 69.8u C and 63.8u C, corresponding to the wild type and mutated MOR allele, respectively. The results from FRET-PCR were validated by sequencing and restriction-fragment length polymorphism (RFLP). Screening of blood samples from 100 subjects showed an allelic distribution for the human MOR alleles of 79% (homozygous wild type), 20% (heterozygous) and 0.9% (homozygous mutated). Conclusions The FRET-PCR protocol for detection of the human MOR gene polymorphism at position 118 offers a rapid and reliable method which could be used for population screening of this and other genes.

The A118G single nucleotide polymorphism of the μ-opioid receptor gene (OPRM1) is associated with pressure pain sensitivity in humans

“…The A118G polymorphism of OPRM1-in which the adenine nucleotide located at position 118 is replaced by a guanine-is relatively common, with at least one rare G allele (ie, AG or GG genotypes) occurring in approximately 20% to 30% of the population. 3,20,46 This nucleotide substitution results in a change of amino acid at position 40 (in exon 1) of the receptor protein from asparagine to the negatively charged aspartate. Moreover, some functional consequences of this SNP have been reported, in that the A118G variant -opioid receptor shows greater binding affinity for ␤-endorphin, 3 which represents a potential mechanism whereby this SNP may alter pain sensitivity.…”

A mu-opioid receptor single nucleotide polymorphism in rhesus monkey: association with stress response and aggression

“…Noteworthy, analogous screening for G118 alleles in the human also shows that homozygosity for the rarer allele is uncommon. 2,8 The A118G polymorphism in the human mu-opioid receptor gene is associated with enhanced HPA axis responses to opioid receptor blockade by naloxone. 3 More broadly, it has been suggested that persons harboring a G118-containing allele may have abnormal HPA axis responses to stress.…”

Pharmacogenetics: implications for obstetric anesthesia

“…The l-OR is a GPCR, and a number of SNPs have been described for OPRM 1 . 50,51 At nucleotide position 118, an adenine substitution by a guanine (A118G), changing the asparagine residue at amino acid position 40 into an aspartate residue (Asn40Asp), has been reported to occur at an allelic frequency of 10-20%. [51][52][53] In vitro, the A118G polymorphism seems to increase the binding affinity and potency of b-endorphin.…”