- CC = Normal Dopamine Receptors (DRD2)
- A (minor) = Increased DRD2 signaling. Altered splicing of DRD2 protein, which decreases the ratio of D2S and D2L and subsequently increases dopamine signaling [R]. The D2 long isoform (D2L) is mainly postsynaptic and is a target for haloperidol, and the D2 short (D2S) isoform is mainly presynaptic and serves as an autoreceptor regulating (inhibiting) dopamine synthesis and release (R).
The Minor "A" Allele is Associated With:
- Increased risk of cocaine-related death[R].
- Increased risk of establishing opioid dependence [R].
- More likely to develop alcoholism (P=0.03, OR=1.3) [R], (R)
- A higher risk of developing schizophrenia (Han Chinese) [R].
- Reduced performance in working memory and maintaining attention [R].
- 10X higher risk of developing psychosis in daily cannabis users [R].
The Major "C" Allele is Associated With:
- 3.5X increased risk of developing psychosis in daily cannabis users [R]
This SNP is Associated With:
- High association with dyslexia was found in Chinese primary school students [R]
- Mice lacking DRD2 exhibited Parkinsons-like symptoms [R]
- A change in DRD2 shows a possible link to Tourette's Syndrome, especially in white males (OR=1.65) [R]
This SNP is associated with brain anatomy and function in healthy people.
rs1076560 is associated with neuronal connectivity in the amygdala, dorsolateral prefrontal cortex and striatal regions (R, R), and differences in resting posterior minus frontal EEG slow oscillations (R).
Brain activity in the left basal ganglia, thalamus, supplementary motor area, and primary motor cortex was also found to be associated with rs1076560 (R). These differences in brain function have been found to correlate with alterations in working memory, reaction time and impairments in negative decision making (R, R, R, R).
The minor A allele has been associated with lower working memory and schizophrenia (R, R, R). and an interaction between rs1076560 and a SNP in AKT1 is associated with the response to olanzapine in schizophrenic patients (R).
rs1076560 is also found to increase risk for psychiatric disorders such as schizophrenia and also the risk for developing substance dependence in both Blacks, Europeans and Asian populations.