Association between schizophrenia and DRD3 or HTR2 receptor gene variants

Abstract

Schizophrenia is a severe and common psychiatric disorder afflicting 1% of the world population. A role of many neurotransmitter receptors in schizophrenia was suggested by an association with several polymorphisms located in their coding regions. In this study we examined the contribution of the T-102C and A-206G transitions in the 5-HTR2a and DRD3 receptor genes respectively to genetic susceptibility and phenotypic expression of schizophrenia disorder within the Greek population. We determined by PCR and RFLP analysis the genotype for the above polymorphisms in 114 schizophrenic hospitalized individuals and 192 control samples. In contrast to previous reports from large European multicentre studies, which indicate significant correlation between schizophrenia and C-102 allele of the T-102C polymorphism, in this study we observed a statistically significant overall association between the disorder and allele T-102 (Po0.0001, odds ratio (OR) ¼ 2.11, 95% CI ¼ 1.48-3.02). We also found a highly significant excess of the T-102/C-102 and C-102/C-102 genotypes in the normal group (Po0.001). Comparison of the patients with the controls for the DRD3 polymorphism (A-206G transition) showed marginally nonsignificant differences in the genotypic (P ¼ 0.054) and no significance in the allelic (P ¼ 0.163) frequencies. However, the A-206/ A-206 genotype seems to positively contribute to the disorder appearance, when compared to A-206/ G-206 as genotype base line risk (P ¼ 0.016, OR ¼ 1.88, 95% CI ¼ 1.09-3.26). In conclusion, from genetic association analysis of this schizophrenic population, a significant association is clearly determined between the HTR2 genetic polymorphism and the presence of schizophrenic disorder, manifested as increased risk of schizophrenia for carriers of the T-102 allele.

Association of the T102C polymorphism in the HTR2A gene with major depressive disorder, bipolar disorder, and schizophrenia

“…Although the association between the T102C polymorphism and MDD, BPD, and SCZ has been explored in many studies, the findings are inconsistent. Some studies have suggested that the T102C polymorphism is associated with susceptibility to MDD [Du et al, ; Li et al, ] and SCZ [Erdmann et al, ; Baritaki et al, ]; however, a number of studies failed to provide evidence to support these associations [Illi et al, ; Yosifova et al, ; Pakhomova et al, ]. As far as we know, a meta‐analysis confirming an association between the T102C polymorphism and MDD has not been published to date, and the meta‐analysis conducted by Seifuddin [] to investigate the T102C polymorphism and BPD did not give a definitive conclusion.…”

Genetic variation in the serotonin 2A receptor and suicidal ideation in a sample of 270 Irish high‐density schizophrenia families

“…Several reports of association between HTR2A polymorphisms and schizophrenia have been published [Erdmann et al, 1996; Inayama et al, 1996; Williams et al, 1996; Baritaki et al, 2004]. These have mostly examined one to three polymorphisms each, of which a T/C polymorphism at position 102 (T102C) has been most frequently studied.…”

Relevance of Competency-based Education to Work with Individuals with Serious Mental Illness

“…Change in the levels of neurons such as dopamine and serotonin are identified in individuals with schizophrenia (Baritaki et al, 2004;Hirvonen et al, 2006). Psychological factors that make an individual more vulnerable to the onset of illness include being exposed to diathesis, which is related to the humoral (body fluids) theory of temperament and disease; the presence of schism, which means the parents are bitterly divided on most issues; and skew, which means there is an imbalance in the power relationship between the parents (Lidz, 1972); and familial patterns and double-bind communication (Bateson, 1978).…”