Epigenetic and Genetic Factors Associated With Opioid Use Disorder: Are These Relevant to African American Populations

Abstract

In the United States, the number of people suffering from opioid use disorder has skyrocketed in all populations. Nevertheless, observations of racial disparities amongst opioid overdose deaths have recently been described. Opioid use disorder is characterized by compulsive drug consumption followed by periods of withdrawal and recurrent relapses while patients are participating in treatment programs. Similar to other rewarding substances, exposure to opioid drugs is accompanied by epigenetic changes in the brain. In addition, genetic factors that are understudied in some racial groups may also impact the clinical manifestations of opioid use disorder. These studies are important because genetic factors and epigenetic alterations may also influence responses to pharmacological therapeutic approaches. Thus, this mini-review seeks to briefly summarize what is known about the genetic bases of opioid use disorder in African Americans.

Opioids and opioid receptors; understanding pharmacological mechanisms as a key to therapeutic advances and mitigation of the misuse crisis

“…It is generally accepted that in opioid use disorder (addiction) there is hypermethylation of MOP receptor promoters (where transcription is initiated). 91 What are the effects of shorter-term therapeutic use? This has been addressed by Sandoval-Sierra and colleagues who examined genome-wide DNA methylation in the MOP promoter.…”

Neural Network Connectivity Following Opioid Dependence is Altered by a Common Genetic Variant in the µ-Opioid Receptor,OPRM1A118G

“…Opioid use disorder (OUD) is a chronic relapsing brain disease that accounted for a staggering 70% of over 100,000 drug overdose deaths in the USA from 2021 to 2022 ( Commonwealth Fund, 2022 ; Cook, 2022 ). Genetic variants, such as single nucleotide polymorphisms (SNPs), have been associated with OUD susceptibility ( Blackwood and Cadet, 2021 ). A commonly reported SNP in the gene encoding the µ-opioid receptor ( OPRM1 A118G SNP; rs1799971) has an amino acid replacement of asparagine (N) to aspartic acid (D) at an N-glycosylation site of the receptor resulting in reduced receptor expression ( Huang et al, 2012 ; Browne et al, 2017 ).…”