Genetic variation in circadian rhythm gene CLOCK with susceptibility to multiple sclerosis

Introduction: Multiple Sclerosis (MS) is the most common disabling neurological disorder of young adults that cause inflammatory demyelinating disease of the central nervous system. Evidence from epidemiological studies indicates the prevalence of MS varies with geographic latitude, increasing with distance from the equator. The factors such as fluctuations in temperature day, length and light intensity during different seasons sustain the human circadian rhythms. Interior circadian rhythms are regulated by circadian rhythm genes. The discordance of circadian rhythms is associated with numerous disorders such as neurodegenerative diseases. The aim of this study was to determine a possibility of associating the rs6811520 T>C polymorphism in CLOCK gene with MS.Materials and Methods: 55 patients with MS referred to Ayatollah Kashani Hospital in Isfahan and 60 healthy individuals as control group was selected. DNA was extracted from whole blood and then all subjects were genotyped for the rs6811520 polymorphism in the CLOCK gene by high-resolution melting (HRM) real-time PCR technique. The HRM results confirmed by PCR-Sequencing. Statistical analyses were done with version 20 of SPSS software.Results: Our finding displayed a statistically significant difference in genotype and allele frequency between two groups concerning rs6811520 (P = 0.027, for C allele) polymorphism within the CLOCK gene.Conclusion: The results presented that CLOCK genetic polymorphism are associated with increased risk of MS in Iranian population. However, functional studies are required to explain how this SNP contributes to MS pathogenesis.

کلیدواژه ها:

Multiple Sclerosis ، CLOCK gene ، Polymorphism