Several studies have demonstrated a correlation between Attention Deficit Hyperactivity Disorder (ADHD), circadian rhythmicity and sleep disturbances in unmedicated ADHD patients (4). Research by Xu et al 2010, supports findings that a genetic variation of the CLOCK gene, rs1801260, is a risk factor in the development of ADHD. The study observed an association between the T allele of the SNP, rs1801260, and increased susceptibility to ADHD (5).
In contrast, this same SNP, also known as CLOCK 3111 T/C, has been linked to eating behaviors and obesity in carriers of the C allele when compared to individuals homozygous for the T allele. Carriers of the C allele were also more resistant to weight loss and recorded shorter durations of sleep (6). Interestingly, another SNP, rs11932595 within the CLOCK gene has also been shown to associate with sleep disruptions and contribute to depression in young adults (7). Taken together, the research indicates that SNPs in CLOCK genes have an impact on multiple areas of study. For more research on the CLOCK gene, visit SNPedia here.
When interpreting data from your current study or planning for the future, consider the polymorphisms that influence the circadian rhythm and the related disorders. For a complete list of SNPs available for research, we recommend contacting one of our experts for guidance on the most relevant selections for your research.
|Gene:||Circadian Locomotor Output Cycles Kaput|
|Related Analyte(s):||Melatonin, Insulin, Cortisol|
|Genomic DNA, purified using silica based membrane columns is analyzed by TaqMan® SNP Genotyping Assays run on the 7900HT real time PCR system
Yield: 2-5 ug genomic DNA
Collect Saliva Samples
DNA SALIVA COLLECTION CONSIDERATIONS
Better results begin with better saliva collection. This collection protocol features general considerations to maximize salivary DNA analysis. Use this collection protocol to plan your collection methodology and sampling schemes.
APPROVED SALIVARY DNA COLLECTION METHODS
Test Saliva Samples
|Order Code (lab):||5811 (SNP Genotyping)|
|Transport Requirements:||Ship on Dry Ice|
The validated method used by Salimetrics is proprietary and not available in assay kit form at this time.
References & Salivary CLOCK Related Research
- Edgar, R. et al. (2012). Peroxiredoxins are conserved markers of circadian rhythms. Nature. 485(7399), 459-464.
- NCBI: CLOCK clock circadian regulator [ Homo sapiens (human) ]
- Hardin, P. et al. (2000). From biological clock to biological rhythms. Genome Biology. 1(4), 1023.1-1023.5.
- Kissling, C. et al. (2008). A polymorphism at the 3′-untranslated region of the CLOCK gene is associated with adult attention-deficit hyperactivity disorder. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics. 147(3), 333-338.
- Xu, X. et al. (2010). Association study between a polymorphism at the 3′-untranslated region of CLOCK gene and attention deficit hyperactivity disorder. Behavioral and brain functions: BBF. 6,48.
- Garaulet, M. et al. (2011). Ghrelin, Sleep Reduction and Evening Preference: Relationships to CLOCK 3111 T/C SNP and Weight Loss. PLoS ONE, 6(2), e17435.
- Vanderlind, W. M. et al. (2014). Sleep and sadness: exploring the relation among sleep, cognitive control, and depressive symptoms in young adults. Sleep Medicine, 15(1), 144–149.