Rs7221412

A common polymorphism near PER1 and the timing of human behavioral rhythms. Study showed that it had influence on wake-up times, as well as time of day that death occurs. Suggests that common (but unidentified) polymorphisms may be associated with a preference for daytime or nighttime activity.

rs7221412 is not presently covered by 23andMe, but this SNP appears to sit in a haplotype block and is flanked by rs9914077 and rs2585408