Current Data on the Genetic Background of Impulse Control Disorders in Parkinson’s Disease

Impulse Control Disorders (ICDs) are increasingly recognized non-motor complica-tions in PD patients with multiple negative consequences for the individual and care-givers. ICDs are frequently observed in PD patients treated with dopaminergic agents, however not all patients develop these behavioral disorders, suggesting that other fac-tors may increase susceptibility for PD-ICDs. This review aims to analyze current knowledge on the genetic background of ICDs. For this narrative review article, we searched PubMed and Scopus databases for peer-reviewed research, review articles, and meta-analyses regarding the role of genetics in ICDs, published in the English language with no time restrictions. References of the selected articles for possible addi-tional articles were also screened in order to include most of the key recent evidence. This review pinpoints the critical role of genes that encode for enzymes, transporters and receptors that participate in the dopaminergic system, in ICD pathogenesis. Glu-tamate receptor, ionotropic, N-methyl-d-aspartate 2B (GRIN2B), involved in the glu-tamatergic pathway and hydroxytryptamine receptor 2A (HTR2A) and tryptophan hydroxylase 2 (TPH2) involved in the serotoninergic pathways, are also highlighted as important risk factors, as well as Opioid receptor kappa 1 (OPRK1) and Opioid recep-tor Mu 1 (OPRM1) that participate in the opioid system. Early recognition of genetic factors that increase susceptibility for ICDs in PD patients is awaited to increase diag-nostic accuracy and expedite individualized treatment.