CRY1 and CRY2 genetic variants in seasonality: A longitudinal and cross-sectional study.
Cryptochromes are key components of the circadian clocks that generate and maintain seasonal variations. The aim of our study was to analyze the associations of CRY1 and CRY2 genetic variants with the problematicity of seasonal variations, and whether the problematicity of seasonal variations changed during the follow-up of 11 years. Altogether 21 CRY1 and 16 CRY2 single-nucleotide polymorphisms (SNPs) were genotyped and analyzed in 5910 individuals from a Finnish nationwide population-based sample who had filled in the self-report on the seasonal variations in mood and behavior in the year 2000. In the year 2011, 3356 of these individuals filled in the same self-report on the seasonal variations in mood and behavior. Regression models were used to test whether any of the SNPs associated with the problematicity of seasonal variations or with a change in the problematicity from 2000 to 2011. In the longitudinal analysis, CRY2 SNP rs61884508 was protective from worsening of problematicity of seasonal variations. In the cross-sectional analysis, CRY2 SNP rs72902437 showed evidence of association with problematicity of seasonal variations, as did SNP rs1554338 (in the MAPK8IP1 and downstream of CRY2).
Department of Health, National Institute for Health and Welfare (THL), Helsinki, Finland. Electronic address: leena.kovanen@thl.fi.
Leena
L
Kovanen
Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland.
Kati
K
Donner
Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland; Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland.
Mari
M
Kaunisto
Department of Health, National Institute for Health and Welfare (THL), Helsinki, Finland.
Timo
T
Partonen
D000328:Adult; D016022:Case-Control Studies; D057906:Circadian Clocks / Q000235:genetics; D002940:Circadian Rhythm / Q000235:genetics*; D003430:Cross-Sectional Studies; D056931:Cryptochromes / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D011446:Prospective Studies; D012044:Regression Analysis; D016574:Seasonal Affective Disorder / Q000235:genetics*; D012621:Seasons
C538963:CRY1 protein, human; C538966:CRY2 protein, human; D056931:Cryptochromes
Behavior; Circadian; Cryptochrome; Diurnal; Genetic association; Mood; Population