Rs6280

rs6280, also known as Ser9Gly, is a SNP in the dopamine receptor D3 DRD3 gene. The rs6280(C) allele encodes a glycine, and the (T) allele encodes a serine (in dbSNP orientation).

In a study of 88 patients being treated for schizophrenia with olanzapine, those who were rs6280(C;C) homozygotes had greater positive symptom remission (endpoint rating of minimal or none on all PANSS clinical response positive items, 39.1%), as compared with (C;T) or (T;T) genotypes (13.8%; p = 0.033).

Ser9Gly has been implicated in executive function in some studies, but the results are conflicting.
 * Gly/Gly carriers showed significantly (p = 0.002) poorer performance than Ser/Ser carriers on executive functioning tasks in a somewhat small Caucasian sample (84 patients with first-episode psychosis and 85 controls).
 * Gly/Ser heterozygotes had 23% more preservative errors on the WCST compared to Ser/Ser homozygotes in a small (216) healthy Han Chinese sample (p = 0.009). Differences between homozygotes were not statistically significant.
 * No association between WCST scores and Ser9Gly was found in 138 schizophrenic patients.

Associated in a family association study and pooled sample of 2,037 with nicotine dependence in Americans of European descent.

Preliminary evidence for an association between a dopamine D3 receptor gene variant and obsessive-compulsive personality disorder in patients with major depression. DRD3 polymorphism for an individual with Gly/Gly (C;C) genotype is 2.4 (P = 0.017) times more likely to be diagnosed with OCPD. Male gender was also found to be a significant predictor of OCPD diagnosis (OR = 2.82, P = 0.001). DRD3 may contribute to the development of OCPD. This association was tested using two independent groups of individuals with a history of depression, from a clinical sample (n = 149) and a family study (n = 213).