Molecular genetic polymorphism of the genes of neurotransmitter systems inschizophrenics with early manifestation of the disease

Molecular-genetic polymorphism of genes-candidates was investigated: the ge nes of serotonin receptor-type 2a (HTR2A), dopamine receptor gene-type 2, s erotonin transporter (5HTTLPR). Thirty one schizophrenic patients whose age was 12,6 +/- 3,6 years at the onset of the disease and 208 patients whose age was 23,5 +/- 6,7 years at the onset of the disease were examined. The f requencies of HTTLPR and DRD2 genotypes differed insignificantly in both gr oups. The distribution of 5HTR2A genotypes in the schizophrenic group with an early manifestation of the disease differed from that with a later manif estation significantly (chi (2)=6,27; df=2; p=0,044). The relative risk (od ds ratios) was 7,9 with 95% significance interval 1,008-61,94; p=0,045. The severity of the disease and a positive family history were also examined i n A2A2 genotype carriers. A positive family history was found in 9 (52,9%) of the 17 schizophrenics with an early manifestation and only in 15 (21,1%) of 71 patients of the similar group with a later one. Assessment of the cl inical symptoms revealed that the total scores by the negative symptomatolo gy subscale (PANSS) was higher in the patients with an early manifestation than in those with later one; but these differences did not achieve the sig nificance level. These and earlier findings lead to the conclusion that A2A 2 genotype was more frequently observed in the patients with more pronounce d negative symptoms and high hereditary burden, which suggests that the A2A 2 genotype is associated with an early onset.