Polymorphism in the PER3 promoter associates with diurnal preference and delayed sleep phase disorder.

Archer SN, Carpen JD, Gibson M, Lim GH, Johnston JD, Skene DJ, von Schantz M. Sleep. 2010 May 3;(5):695-701.

This study investigated the circadian genetic influence on sleep disorders and chronotypes. Visitors to the London Science Museum were recruited and completed the Horne-Östberg diurnal preference questionnaire and provided buccal DNA samples. In addition, a second patient population of individuals diagnosed with delayed sleep phase disorder (DSPD) were investigated. The authors found that those with the rs2797687 SNP on per3 were more likely to have DSPD compared to individuals with an evening chronotype. The TA2G haplotype was also associated with DSPD, as compared to evening chronotypes.

rs2797687 SNP in per3

per3 rs2797687

NCBI Variation Viewer rs2797687

Circadian Polymorphisms in Night Owls, in Bipolars, and in Non-24-Hour Sleep Cycles

Kripke D, Klimecki W, Nievergelt C, Rex K, Murray S, Shekhtman T, Tranah G, Loving R, Lee H, Rhee M, Shadan F, Poceta J, Jamil S, Kline L and Kelsoe J. Psychiatry Investig. 2014 Oct; 11(4): 345–362.

To determine potential causes of delayed sleep phase syndrome (DSPS), a disease where patients have difficulty falling asleep at night and arising in the morning, a study performed in 826 people from the United States found that 2 SNPs are associated with DSPS. The two SNPs are rs2482705 SNP in nfil3 and the rs3828057 SNP in ror-c. 

rs2482705 in nfil3

nfil3 rs2482705

NCBI Variation Viewer rs2482705

rs3828057 on ror-c

ror-c rs3828057

NCBI Variation Viewer rs3828057