Allele polymorphism of the dopamine transporter gene in patients with endogenous psychoses: Association with pathological syndromes

A study was made of the association of the allele polymorphism of the 3′VNTR locus of the dopamine transporter (DAT) gene with schizophrenia, schizo-affective psychosis, and affective disorders. Three alleles (440, 480, and 520 nt) were found and the allele and genotype frequencies estimated in all groups. The allele and genotype frequencies in patients with depression significantly differed from those in controls and in patients with bipolar affective psychosis and schizophrenia. The results were correlated with the averaged MMPI profiles of controls and affective patients. In the latter group, 480/480 homozygotes significantly differed from patients with the other genotypes in the mean score on Hypochondria and Hysteria scales. The possible association of the DAT-3′VNTR polymorphism and individual syndromes, which are related to different mechanisms of psychological defense, is discussed.