%0 Journal Article %T ARNTL (BMAL1) and NPAS2 Gene Variants Contribute to Fertility and Seasonality %A Leena Kovanen %A Sirkku T. Saarikoski %A Arpo Aromaa %A Jouko L£¿nnqvist %A Timo Partonen %J PLOS ONE %D 2012 %I Public Library of Science (PLoS) %R 10.1371/journal.pone.0010007 %X Circadian clocks guide the metabolic, cell-division, sleep-wake, circadian and seasonal cycles. Abnormalities in these clocks may be a health hazard. Circadian clock gene polymorphisms have been linked to sleep, mood and metabolic disorders. Our study aimed to examine polymorphisms in four key circadian clock genes in relation to seasonal variation, reproduction and well-being in a sample that was representative of the general population, aged 30 and over, living in Finland. %U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0010007