Circadian Rhythm Gene CLOCK Polymorphisms and the Risk of Schizophrenia Among Iranian Patients

Abstract

Background: Schizophrenia is a type of neuropsychiatric disorder that is defined by hallucinations, disturbed thinking, and cognitive impairment. However, the pathogenesis and cause of schizophrenia remain elusive. Previous research demonstrated that schizophrenic patients have irregular circadian rhythms. Circadian locomotor output cycles kaput (CLOCK) is a key component of the circadian clock system and is involved in a wide range of mammals’ physiological, metabolic, and behavioral processes. A change in the CLOCK gene may be linked to both common mental and circadian disorders. Objectives: This study aimed to investigate the possible relationship between rs1801260 and rs6811520 polymorphisms in the CLOCK gene, as the principal regulator of the circadian rhythm, with susceptibility to schizophrenia in the Iranian population. Methods: DNA samples were obtained from the venous blood of 103 people with schizophrenia and 100 unrelated healthy people in Dezful, southwest Iran. The high-resolution melting (HRM) method was used for genotyping the CLOCK gene SNPs, including rs1801260 and rs6811520. The PCR and DNA sequencing confirmed the HRM results. Results: We found a correlation between schizophrenia and the CLOCK SNP rs6811520. In addition, our findings demonstrated that the SNP rs1801260 did not contribute to schizophrenia. Conclusions: The findings of this study demonstrate that changes in the CLOCK gene may contribute to schizophrenia.