Clock T3111C and Per2 C111G SNPs do not influence circadian rhythmicity in healthy Italian population
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A possible relationship between human circadian rhythmicity and polymorphisms in clock genes have been documented. However, these data are controversial, and studies both corroborating and denying them have been reported. T3111C Clock polymorphism had been associated with the human evening preference, however, this association has not been confirmed. Moreover, C111G Per2 polymorphism has been associated with the “morning larks” chronotype in one study, not yet replicated. We have, therefore, performed this study to evaluate whether Per2 C111G and Clock T3111C polymorphisms might influence sleep circadian rhythmicity in a sample of 219 Italian volunteers. A possible interaction between these polymorphisms was also investigated. No differences in Per2 C111G and Clock T3111C allele and genotype frequencies were found, and none of the combined Clock T3111C–Per2 C11G genotypes resulted more frequent in one group compared to the others. Present results do not support a role of these polymorphisms in the circadian phenotypes.
KeywordsClock Human circadian rhythmicity Per2 SNPs
This work was performed in the frame of AMBISEN Center, High Technology Center for the study of the Environmental Damage of Endocrine and Nervous System, University of Pisa.
- 2.Daan S, Beersma DG, Borbely AA (1984) Timing of human sleep: recovery process gated by a circadian pacemaker. Am J Physiol 246:161–183Google Scholar
- 5.Mishima K, Tozawa T, Satoh K, Saitoh H, Mishima Y (2005) The 3111T/C polymorphism of hClock is associated with evening preference and delayed sleep timing in a Japanese population sample. Am J Med Genet B Neuropsychiatr Genet 133:101–104Google Scholar
- 6.Robilliard DL, Archer SN, Arendt J, Lockley SW, Hack LM, English J, Leger D, Smits MG, Williams A, Skene DJ, Von Schantz M (2002) The 3111 Clock gene polymorphism is not associated with sleep and circadian rhythmicity in phenotypically characterized human subjects. J Sleep Res 11:305–312CrossRefPubMedGoogle Scholar
- 17.Ciarleglio CM, Ryckman KK, Servick SV, Hida A, Robbins S, Wells N, Hicks J, Larson SA, Wiedermann JP, Carver K, Hamilton N, Kidd KK, Kidd JR, Smith JR, Friedlaender J, McMahon DG, Williams SM, Summar ML, Johnson CH (2008) Genetic differences in human circadian clock genes among worldwide populations. J Biol Rhythms 23:330–340CrossRefPubMedGoogle Scholar