Seasonality associated with the serotonin 2A receptor − 1438 A/G polymorphism

Seasonal affective disorder and seasonal rhythms in mood and behavior (seasonality) have been reported to be associated with serotonergic system. In this study we investigated the relationship between the serotonin 2A receptor (5HTR2A) − 1438 A/G polymorphism and seasonal variation in a young Korean healthy population. 297 young Korean medical students were recruited for this study. They were genotyped for the 5HTR2A − 1438 A/G polymorphism and evaluated the seasonal variation in mood and behavior by the Seasonality Pattern Assessment Questionnaire (SPAQ). The Global Seasonality Score of the SPAQ among three genotypes were not different. However, the comparison between seasonals and non-seasonals showed significant difference in the genotype distribution. The winter-type seasonals showed a significantly higher frequency of the 5HTR2A − 1438 A allele compared with non-seasonals ( χ 2 = 6.80, p = 0.009; OR = 1.79; 95% CI, 1.15–2.78). These results suggest that the 5HTR2A − 1438 A/G polymorphism is possibly related to seasonality in the Korean population.