{{Rsnum
|rsid=1801260
|Gene=CLOCK
|Chromosome=4
|position=55435202
|Orientation=minus
|GMAF=0.2181
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(C;C)
|geno2=(C;T)
|geno3=(T;T)
|Gene_s=CLOCK
}}{{ population diversity
| geno1=(C;C)
| geno2=(C;T)
| geno3=(T;T)
| CEU | 6.2 | 39.8 | 54.0
| HCB | 0.0 | 13.1 | 86.9
| JPT | 1.8 | 36.3 | 61.9
| YRI | 3.4 | 22.4 | 74.1
| ASW | 0.0 | 33.3 | 66.7
| CHB | 0.0 | 13.1 | 86.9
| CHD | 0.9 | 11.0 | 88.1
| GIH | 17.8 | 49.5 | 32.7
| LWK | 2.7 | 24.5 | 72.7
| MEX | 5.2 | 43.1 | 51.7
| MKK | 5.1 | 43.6 | 51.3
| TSI | 6.9 | 39.2 | 53.9
| HapMapRevision=28
}}

[[rs1801260]], a SNP in the [[CLOCK]] gene known as 3111 T/C, has been reported to influence sleep and activity patterns in patients affected by bipolar [[depression]]. {{PMID|17221848}}

From this article's abstract:

"Compared to T/T homozygotes, carriers of the C allele had a similar degree of severity of depression, but showed higher activity levels in the evening, a delayed sleep onset (mean 79 min later), and a reduced amount of sleep during the night (mean 75 min less)."

{{PMID|20364331}} Allele frequencies of T3111C SNP of hClock were significantly different between schizophrenics and controls (chi(2) = 19.738, P < 0.05). Schizophrenics had a significantly higher frequency of the C allele compared with controls (OR = 2.613, 95% CI = 1.693-4.034).  (Han Chinese population.)

{{PMID|17948273}} There was a strong, significant association (P < 0.001) between both self-rating and interview-based adult ADHD assessments and the rs1801260 polymorphism with at least one T-mutation being the risk allele.

{{PMID|20065968}} rs1801260 variations associated with weight loss while on Mediterranian diet.  Carriers of the G allele displayed greater difficulty in losing weight than non-carriers. 

{{PMID|17428266}} CLOCK 3111 T/C SNP was associated with activity levels in the second part of the day, neuropsychological performance and BOLD fMRI correlates (interaction of genotype and moral valence of the stimuli). 

{{PMID Auto
|PMID=20704703
|Title=Association study between a polymorphism at the 3'-untranslated region of CLOCK gene and attention deficit hyperactivity disorder
|OA=1
}}

{{PMID Auto
|PMID=21773969
|Title=Functional polymorphisms of circadian positive feedback regulation genes and clinical outcome of Chinese patients with resected colorectal cancer
}}

{{PMID Auto
|PMID=22517501
|Title=Rotating night shift work and polymorphism of genes important for the regulation of circadian rhythm
}}

{{PMID|18071340}} Association between polymorphisms in the Clock gene, obesity and the metabolic syndrome in man.

{{PMID|18228528|OA=1
}} Clock genes may influence bipolar disorder susceptibility and dysfunctional circadian rhythm.

{{PMID|18663240|OA=1
}} Genetic differences in human circadian clock genes among worldwide populations.

{{PMID|18957941|OA=1
}} Genome-wide association scan for five major dimensions of personality.

{{PMID|19166596|OA=1
}} Circadian polymorphisms associated with affective disorders.

{{PMID|20180986|OA=1
}} CLOCK is suggested to associate with comorbid alcohol use and depressive disorders.

{{PMID|20368993|OA=1
}} ARNTL (BMAL1) and NPAS2 gene variants contribute to fertility and seasonality.

{{PMID|20396431|OA=1
}} Genotyping sleep disorders patients.

{{PMID|20600471}} Association between CLOCK 3111T/C and preferred circadian phase in Korean patients with bipolar disorder.

{{PMID|22310473}} SIRT1 and CLOCK 3111T>C combined genotype is associated with evening preference and weight loss resistance in a behavioral therapy treatment for obesity.

{{PMID Auto
|PMID=23131019
|Title=Physical Activity and Sex Modulate Obesity Risk Linked to 3111T/C Gene Variant of the CLOCK Gene in an Elderly Population: The SUN Project
}}

{{PMID|22709985}}
"Circadian locomotor output cycles kaput (CLOCK) molecule plays major roles in circadian rhythmicity and regulates daily physiological processes including digestive activity. Therefore, we hypothesized that the CLOCK 3111T/C single nucleotide polymorphism (SNP) might have adverse effects on the regulation of gastric motility."

{{PMID|20961464|OA=1
}}
"The clock molecule plays major roles in circadian rhythmicity and regulating lipid and glucose metabolism in peripheral organs. Disruption of the circadian rhythm can lead to cardiometabolic disorders."

{{PMID|23399917}}
"Here, we find that cholecystokinin (Cck) is a direct transcriptional target of CLOCK and levels of Cck are reduced in the ventral tegmental area (VTA) of ClockΔ19 mice. Selective knockdown of Cck expression via RNA interference in the VTA of wild-type mice produces a manic-like phenotype"

{{PMID|24467926}}
" C genetic variants in CLOCK 3111 T/C are more obese and lose less weight in
a dietary and behavioral treatment for obesity than TT carriers and they are also more
evening-type subjects "

[[Attention-Deficit Hyperactivity Disorder]]

{{PMID Auto
|PMID=24892753
|Title=PER2 rs2304672, CLOCK rs1801260, and PER3 rs57875989 polymorphisms are not associated with juvenile myoclonic epilepsy
}}

{{PMID Auto
|PMID=25020710
|Title=P324Circadian genes in the regulation of lipids in coronary artery disease
}}
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