Association between the melanopsin gene polymorphism OPN4*Ile394Thr and sleep/wake timing in Japanese university students

Abstract

BackgroundIn our previous studies, we found that the Ile394Thr SNP in the melanopsin gene (OPN4) was functionally associated with the pupillary light reflex. This indicates the possibility that OPN4*Ile394Thr is associated with other non-image forming responses. The aim of this study was therefore to determine whether OPN4*Ile394Thr is associated with sleep/wake timing.MethodsA total of 348 healthy Japanese university students participated in this study. Scalp hair was used to genotype the Ile394Thr SNP of OPN4. Sleep habits, including bedtime, wake time and sleep duration, were assessed separately for weekdays and weekends. A total of 328 samples, including 223 samples with TT genotype, 91 with TC genotype and 14 with CC genotype, were used for statistical analysis. No significant difference in age or male/female distribution was found among the three genotype groups.ResultsThere was no significant difference in circadian preference among the genotype groups. During weekdays, bedtime, wake time and midpoint of sleep for CC subjects were significantly later than those for TT and TC subjects. However, there was no difference between TT and TC subjects in any of their sleep habits. During weekends, bedtime of CC subjects was significantly later than those of TT and TC subjects, and the midpoint of sleep of CC subjects was significantly later than that of TC subjects.ConclusionsOur findings demonstrated that OPN4*Ile394Thr is associated with sleep/wake timing. We also found that the sleep/wake timing of subjects with the CC genotype was later than that of subjects with the TT or TC genotype.

Melanopsin‐mediated pupillary light reflex and sleep quality in patients with normal tension glaucoma

“…One possible explanation to this phenomenon of normal sleep quality despite reduced melanopsin activity was proposed as the absence of the TT allele of the melanopsin gene (OPN4) (Adhikari et al 2016b). The TT genotype has been shown to be less sensitive to light and associated with disturbed sleep quality (Roecklein et al 2012;Higuchi et al 2013;Lee et al 2013Lee et al , 2014. The role of the TT genotype cannot be ruled out in our study.…”

Impact of seasons on an individual’s chronotype: current perspectives

“… 80 Lee et al demonstrated that the rs1079610 SNP in OPN4 , previously functionally associated with pupillary light reflex and light sensitivity, 81 was associated with habitual sleep timing in Japanese university students. 82 While students of all three genotypes of this SNP had relatively low MEQ scores, those who were homozygous CC had significantly later bedtimes and midpoints of sleep. 82 …”

“… 82 While students of all three genotypes of this SNP had relatively low MEQ scores, those who were homozygous CC had significantly later bedtimes and midpoints of sleep. 82 …”

Defining the impact of melanopsin missense polymorphisms using in vivo functional rescue

“…Next, circadian photoentrainment of hOPN4 AAV-treated Opn4 − / − Cre +/+ mice was examined. It has previously been suggested these behaviours may be disrupted in individuals with either Pro10Leu or Thr394Ile ( 9 , 13 ). To test this association, a circadian screen was conducted using passive infra-red (PIR) detection to monitor the locomotor activity of Opn4 − / − Cre +/+ mice injected with hOPN4 WT , Pro10Leu and Thr394Ile AAV.…”

“…These pupil deficits were not seen in individuals with the CT and CC genotypes. Lee et al ( 13 ) also found that individuals with the Thr394Ile CC genotype had disrupted sleep-wake timing, compared to CT or TT genotypes.…”