HUMAN MU-OPIOID RECEPTOR GENE POLYMORPHISMS AND VULNERABILITY TO SUBSTANCE-ABUSE

Two polymorphisms of the human mu opioid receptor gene are described A non-coding region polymorphism (G to T) occurs at nucleotide 175 prec eding the initiation of translation. A coding polymorphism in exon 1 ( C to T) at nucleotide 229 changes an alanine residue to a valine resid ue. Frequencies of these polymorphisms were examined in groups of coca ine and/or opioid dependent individuals and matched controls. There we re no significant differences between groups, although a trend (p = 0. 05) towards a higher frequency of the 229 valine allele was observed i n the substance abuse group, suggesting a need for large, well-control led studies of this polymorphism in severe substance abusers.