PER3 VNTR polymorphism in Multiple Sclerosis: A new insight to impact of sleep disturbances in MS.

BACKGROUND: Multiple Sclerosis (MS) is a degenerative disease of central nervous system caused by an immune response against the myelin. About half of MS patients suffers from sleep disturbances. The circadian clock genes such as PER3 controls circadian rhythm and sleep. Due to the role of PER3 in sleep disturbances and regulation of immune response, it is possible that PER3 dysregulation increase risk of MS disease.

METHODS: Study groups included 160 MS patients and 160 healthy volunteers. PER3 VNTR polymorphism was evaluated by PCR method. The genotypic and allelic distribution analyzed by chi square test.

RESULTS: There was a significant association between genotype PER34/4 , and 4-repeat allele with MS disease (p = 0.014 and p < 0.001 respectively). The association analysis of PER3 VNTR polymorphism with gender status among MS group, and MS onset showed that there was a significant correlation between PER34/4 genotype with female gender and early onset of MS disease (p = 0.033 and p = 0.028 respectively).

CONCLUSION: Our data suggest that, PER34/4 genotype may accelerate the course of disease in MS susceptible individuals.