The Cys allele (the Ser311Cys polymorphism) of the dopamine d2 receptor is associated with schizophrenia and impairments to selective attention in patients

We report here our studies of the Ser311Cys polymorphism of the D2 dopamine receptor gene in 366 patients with schizophrenia and 387 control subjects. The incidence of the Cys allele was found to be greater ( p < 0.009) among patients than controls (8.5% and 3.9%, respectively). Selective attention was also studied on the basis of assessment of parameters of the P300 wave of auditory evoked potentials in 66 patients with different genotypes – SerSer and SerCys (the CysCys genotype was not seen among the patients). This revealed a significant influence of genotype ( p = 0.01) on the latent period (LP) of the P300 wave in the frontal, central and temporal leads. In carriers of the Cys allele, which is associated with the risk of developing schizophrenia, LP was longer than in subjects with other genotypes, which is evidence for slowing of mental processes associated with activation of attention resources in these subjects. Thus, the results obtained here support data obtained previously for other populations showing that the Cys allele is associated with schizophrenia, and we also observed an association between this allele and degradation of selective attention in patients.