These data suggest that the DRD2 A-241G polymorphism or, alternatively, another genetic variation that is in linkage disequilibrium, may influence response to risperidone in schizophrenia patients.
To investigate whether there is an association of antipsychotic agent-induced weight gain with the TaqI A polymorphism of dopamine D2 receptor (DRD2) gene and therapeutic response to antipsychotic treatment in schizophrenia.
We conclude that the genetic predisposition to schizophrenia in these pedigrees is not due to aberrations in the DRD2 locus or the porphobilinogen deaminase locus.
Genotyping of Ser311Cys, the DRD2 intron 2 STR, and the Taq1A marker in 459 subjects, including 373 sib-pairs and 15 Cys311/Cys311 homozygous individuals, revealed no association to alcoholism, substance use disorders, or schizophrenia.
Our results imply that the genetic variants of DRD2 might not only have a role in susceptibility to schizophrenia, but also influence the phenotypes of negative symptoms and sustained attention in schizophrenia.
We present a schizophrenia association study using an extensive linkage disequilibrium (LD) mapping approach in seven candidate genes with a well established link to dopamine, including receptors (DRD2, DRD3) and genes involved in its metabolism and transport (ACE, COMT, DAT, MAO-A, MAO-B).
Our results are in agreement with an earlier association study suggesting that the C957T C-allele plays a role in the genetic vulnerability for schizophrenia and support the involvement of the DRD2 gene in schizophrenia pathogenesis.
A single nucleotide polymorphism, -141C insertion/deletion (Ins/Del) (rs1799732), in the promoter region of the dopamine D2 receptor gene has been linked to schizophrenia; however, the data are inconclusive.
Recent reports of cytogenetic abnormalities linked to psychiatric illness and the localisations of the genes for the dopamine (D2) receptor and tyrosinase on the long arm of chromosome 11 have suggested that susceptibility loci for schizophrenia and manic depression might be situated in this region.
We found that the mean t-DARPP expression level in the caudate was higher in patients with schizophrenia than in control individuals (P<0.05) and the A1 allele of Taq1A genotype in DRD2/ANKK1 was significantly associated with elevated expression of t-DARPP in the caudate.
The strong association between a potentially functional polymorphism, downstream of the DRD2 gene and schizophrenia, suggests that the direct or indirect functional effects of this polymorphism, acting on either the ANKK1 or DRD2 genes, may play a role in the pathophysiology of schizophrenia.
In this study, we assessed the associations between schizophrenia and polymorphisms in the D2 and D3 dopamine receptor (DRD2, DRD3), the serotonin 2A receptor (5HTR2A), the brain-derived neurotrophic factor (BDNF), the ciliary neurotrophic factor (CNTF) and the neurotrophin-3 (NT-3) genes.
The results suggest that DRD2 polymorphisms may have implications for the symptoms of schizophrenia and a predictor for treatment outcomes in a subgroup of patients with schizophrenia in Malaysia.
These findings suggest that the rare Cys311 variant in exon 7 of the DRD2 receptor gene does not play a role in the pathogenesis of schizophrenia in European populations.