GENETIC RISK FACTORS OF CHRONIC MUSCULOSKELETAL BACK PAIN IN YOUNG PEOPLE

Abstract

Introduction. In recent years, progress in understanding the genetic mechanisms underlying susceptibility to degenerative spinal pathology has been achieved due to advances in molecular genetics. Objective: conduct a comparative analysis of the genotypes and alleles frequencies of type I collagen genes (COL1A1 C-1997A (rs110946) A > C, COL1A1 G-1245T (rs1800012) G > T) and vitamin D receptor (VDR: 283 (Bsml) A > G) in young patients with chronic musculoskeletal back pain. Material and methods. The main group consisted of 70 patients (39 women and 31 men, average age 40 [38; 43] years) with chronic (more than 3 months) musculoskeletal back pain. The control group consisted of 16 healthy individuals (8 women and 8 men, average age 35 [31; 40] years). Determination of the VDR: 238 (Bsml) gene polymorphism was carried out in real time by the polymerase chain reaction (PCR) method on a DT-light amplifier (DNA-Technology, Russia) using reagent kits “Genetics of calcium metabolism” (DNA-Technology, Russia). Determination of collagen gene polymorphisms was carried out by PCR on a Real-time CFX96 Touch amplifier (Bio-Rad Laboratories, USA) using reagent kits produced by Synthol (Russia). Statistical analysis of the obtained data was performed using the SPSS Statistics 19 software package. An allele frequency was calculated by using the formula f = n/2N, the genotypes frequency — by using the formula f = n/N (where N is the sample size, n is the prevalence of variants). The statistical significance of allele and genotype frequencies was assessed using the χ2 criterion. We calculated the odds ratio (OR) to assess the relative risk and its 95% confidence interval (CI): OR = DE/HE/DNE/HNE, where DE and HE are the number of patients in the main and control groups with the risk factor, DNE and HNE — the number of patients without a risk factor. Results. Patients with chronic musculoskeletal back pain differed from the healthy individuals in a higher incidence of flat feet (p = 0.022), spinal scoliosis (p = 0.005), increased fragility of the nail plate (р = 0.000) and myopia (p = 0.25). It has been established that chronic musculoskeletal back pain in young patients is genetically related to the A allele of the vitamin D receptor gene (VDR: 283 (Bsml)) (χ2 = 6.779; p = 0.020; OR = 4.308; 95% CI [1.363; 13.616]). Conclusions. The presence of the A allele of the vitamin D receptor gene (VDR: 283 (Bsml)) in young patients is associated with a genetically determined higher susceptibility to the development of musculoskeletal back pain.