Potassium Channel Allele Modulates Chronic Pain Experience

Chronic musculoskeletal pain is a complex disorder that often causes physical and psychological symptoms. While acute pain promotes healing of damaged tissue, chronic pain is caused by long-term maladaptive changes that result in hyperexcitability of pain-signaling neurons. Potassium channels have recently been implicated in pain syndromes because they largely determine the characteristics for cell activation. The gene KCNS1 encodes for a potassium channel alpha subunit, and a common single nucleotide polymorphism (SNP) in this gene was recently correlated with more severe chronic neuropathic pain. Therefore, this study explores the effects of this KCNS1 SNP on the symptomology of chronic musculoskeletal pain and response to treatment with cognitive behavioral therapy (CBT) or an educational control condition (EDU). The sample included 201 participants with chronic musculoskeletal pain who provided saliva samples from which their DNA was extracted, amplified, and sequenced to determine each participant’s KCNS1 genotype. Participants answered questionnaires measuring physical pain symptoms and psychological suffering at baseline and again following three months of treatment. At baseline, those homozygous for the Val mutation were found to have reduced catastrophizing, lower total pain experience, and greater mental functioning compared to their Val/Ile and Ile/Ile counterparts. Interestingly, all participants improved to the same level of physical and psychological functioning after both treatments regardless of genotype, with greater improvements seen in CBT compared to EDU for all genotypes. Additionally, Ile/Ile individuals tended to improve more in psychological domains, whereas Val/Ile individuals improved more physically. This suggests that KCNS1 genotypic variation can alter the symptomology of chronic musculoskeletal pain and that CBT is an effective chronic pain treatment regardless of KCNS1 genotype. KCNS1 MODULATES CHRONIC MUSCULOSKELETAL PAIN 3