ReportPER3 Polymorphism Predicts Sleep Structure and Waking Performance
Review articleOpen access
2007/04/03 Short communication DOI: 10.1016/j.cub.2007.01.073
Journal: Current Biology
SummaryCircadian rhythmicity and sleep homeostasis interact to regulate sleep-wake cycles 1, 2, 3, 4, but the genetic basis of individual differences in sleep-wake regulation remains largely unknown . PERIOD genes are thought to contribute to individual differences in sleep timing by affecting circadian rhythmicity , but not sleep homeostasis 7, 8. We quantified the contribution of a variable-number tandem-repeat polymorphism in the coding region of the circadian clock gene PERIOD3 (PER3) 9, 10 to sleep-wake regulation in a prospective study, in which 24 healthy participants were selected only on the basis of their PER3 genotype. Homozygosity for the longer allele (PER35/5) had a considerable effect on sleep structure, including several markers of sleep homeostasis: slow-wave sleep (SWS) and electroencephalogram (EEG) slow-wave activity in non-rapid eye movement (non-REM) sleep and theta and alpha activity during wakefulness and REM sleep were all increased in PER35/5 compared to PER34/4 individuals. In addition, the decrement of cognitive performance in response to sleep loss was significantly greater in the PER35/5 individuals. By contrast, the circadian rhythms of melatonin, cortisol, and peripheral PER3 mRNA expression were not affected. The data show that this polymorphism in PER3 predicts individual differences in the sleep-loss-induced decrement in performance and that this differential susceptibility may be mediated by its effects on sleep homeostasis.
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