Effects of genetic variants of <i>ST8SIA2</i> and <i>NCAM1</i> genes on seasonal mood changes and circadian preference in the general population

<p><i>ST8SIA2</i> and <i>NCAM1</i> are functionally related genes forming polysialic acid (PSA) - neural cell adhesion molecule (NCAM) complex in suprachiasmatic nucleus (SCN), the regulating site of circadian biological rhythm. In this study, the relationship of <i>ST8SIA2</i> and <i>NCAM1</i> with circadian and seasonal rhythms of human behavior was explored. Subjects were 261 healthy Korean adults who were free of any history of clinically significant psychiatric symptoms. The phenotypes were circadian preference and seasonal change of mood and behavior (seasonality) measured by the Composite Scale of Morningness and the Seasonal Pattern Assessment Questionnaire, respectively. Thirty-four single nucleotide polymorphisms (SNPs) across the <i>ST8SIA2</i> region and 15 SNPs of <i>NCAM1</i> were analyzed. A nominally significant association with seasonality and circadian preference was observed in 21 variants of both genes. After corrections for multiple testing, associations of 8 SNPs of <i>ST8SIA2</i> and 2 SNPs of <i>NCAM1</i> with seasonality remained significant. Some of these SNPs were also associated with psychiatric disorders in previous studies. This study demonstrated a meaningful and/or suggestive evidence of association between behavioral phenotypes reflecting human biological rhythm and two interplaying genes involved in the plasticity of SCN’s neuronal network.</p>