Association of the Serotonin 2A Receptor rs6311 Polymorphism with Diurnal Preference in Koreans

Abstract

Objective Evidence for the association between circadian rhythm delay and depression is accumulating. Genetic studies have shown that certain polymorphisms in circadian genes are potential genetic markers of diurnal preference. Along with circadian genes, there is a growing interest in other genetic effects on circadian rhythms. This study evaluated whether the <i>HTR2A</i> rs6311 (-1438C/T) polymorphism is associated with diurnal preference in a Korean population.Methods A total of 510 healthy subjects were included in this study. All subjects were genotyped for the <i>HTR2A</i> rs6311 polymorphism and they completed the Korean version of the composite scale of morningness (CSM).Results The C allele carriers (C/C+C/T) showed significantly higher CSM scores compared to C allele non-carriers (T/T) (t=2.22, p= 0.03), suggesting the existence of a morning chronotype tendency in C allele carriers. In other words, the T/T genotype may be associated with the evening chronotype.Conclusion These results suggest that the <i>HTR2A</i> rs6311 polymorphism may be associated with diurnal preference in a healthy Korean population. The absence of the C allele may be responsible for the increasing susceptibility to eveningness in the Korean population. Further studies on <i>HTR2A</i> polymorphisms that evaluate their interactions with various candidate genes and differences in phenotypic expression of polymorphisms according to ethnic groups are warranted to fully understand their association with diurnal preference.

No Association Between the 5-HTTLPR Polymorphism and Diurnal Preference in Koreans

“…1067), and the study was conducted in accordance with the Declaration of Helsinki. Other findings related to these participants have been reported previously [12,16,17,[25][26][27].…”

“…Circadian genes, such as CLOCK, PER2, PER3, CRY1, ARNTL, and RORa, have been investigated for their association with diurnal preference, but many studies did not find any statistical significance or failed to replicate previous positive finding [12][13][14][15][16]. Yeom et al [17] suggested that HTR2A, a gene encoding one of the serotonin receptors, is associated with diurnal preference. Considering the close relationship between the serotonergic and circadian system, this finding seems to be reasonable and leads to the possibility that some other serotonergic genes are associated with diurnal preference.…”

No Association Between NPAS2 rs6425296 Polymorphism and Seasonality, Diurnal Preference in Koreans

“…This study was conducted following the Declaration of Helsinki. Other findings involving these study subjects have been previously reported [25,[28][29][30][31][32][33].…”

Chronotype, circadian rhythm, and psychiatric disorders: Recent evidence and potential mechanisms

“…Other genes that were not the clock were also related to chronotype and psychiatric disorders. A study found that a candidate for Serotonin 2A receptor gene (5HT2A) receptor (HTR2A), which is located on chromosome 13q14-q21, was associated with mental (depression, schizophrenia) and behavioral (suicidal and aggressive behaviors) disorders and was associated with chronotype in a healthy population ( Yeom et al, 2020 ). Additionally, GWAS of the UK Biobank also indicated HTR6 rs2050122 was related to chronotype.…”