Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Family, twin, and adoption studies suggest that genetic factors play an important role in the etiology of schizophrenia. Detection of single gene(s) involved in a higher susceptibility to a hereditary disease is possible with linkage analysis. The effects of serotonin2-receptor antagonists on symptoms of schizophrenia suggest that a mutation in the gene coding for this receptor subtype might be involved in the pathophysiology of this disease. Recently a copy DNA encoding the serotonin 5-HT2 receptor has been isolated and with a human 5-HT2 receptor copy DNA probe the HTR2 locus has been mapped to chromosome 13. Using multipoint linkage analysis between schizophrenia and genetic markers spanning the region of the HTR2 locus, we were able to exclude linkage between this candidate gene and schizophrenia in a Swedish kindred. Given this result, we conclude that the serotonin 5-HT2 receptor gene itself is not a major susceptibility gene for schizophrenia in this family.
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PMID:Exclusion of linkage between the serotonin2 receptor and schizophrenia in a large Swedish kindred. 134 24

A case control study was conducted among cases with schizophrenia (DSM IV criteria) and screened adult controls from three cohorts. Bi-allelic polymorphisms in the promoter region of the serotonin transporter gene (5-HTT) were examined in conjunction with those of the serotonin 5-HT2a receptor (HTR2). No significant association with 5-HTT was detected among US Caucasians (n = 207), African-Americans (n = 84) or Caucasians from Sweden (n = 221). However, survival analysis suggested an association with the age at onset among the Swedish cases. The association should be considered tentative as it was not evident in the smaller US samples. The following exploratory analyses among the US samples were also not significant: associations with subgroups of patients based on familiality or response to medications, or altered risk due to the joint effects of 5-HTT and HTR2 genotypes.
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PMID:Schizophrenia and the serotonin transporter gene. 986 38

Epidemiological and genetic studies of alcoholism and schizophrenia have been performed, and in this study, the human serotonin receptor (HTR2) polymorphism was examined in 75 alcoholics and 31 schizophrenic patients. We found that there might not be a significant difference between these psychiatric disease patients and controls in the frequency of the C1/C2 HTR2 gene (MspI polymorphism). The results suggest that the human HTR2 MspI polymorphism might not be associated with a risk factor for developing alcohol dependence or susceptibility to schizophrenia. It is possible that there may be a racial difference in the frequency of the C1/C2 gene between Japanese and Caucasians. Further studies are required to determine whether or not the novel serotonin receptor polymorphism reflects the pathogenesis of alcoholism or schizophrenia.
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PMID:The human serotonin receptor gene (HTR2) MspI polymorphism in Japanese schizophrenic and alcoholic patients. 1075 25

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 (P<0.0001, odds ratio (OR)=2.11, 95% CI=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 (P<0.001). Comparison of the patients with the controls for the DRD3 polymorphism (A-206G transition) showed marginally nonsignificant differences in the genotypic (P=0.054) and no significance in the allelic (P=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=0.016, OR=1.88, 95% CI=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.
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PMID:Association between schizophrenia and DRD3 or HTR2 receptor gene variants. 1508 67

Aripiprazole is a newer atypical antipsychotic agent used for effective treatment of schizophrenia. It significantly reduces unwanted side effects of older typical antipsychotics by targeting, with high affinity, dopamine D2/D3 and serotonin 5-HT1A/5-HT-2A receptors. Its documented mechanism of action makes it an unlikely agent to cause syndrome of inappropriate antidiuretic hormone secretion (SIADH). We present the first reported case of SIADH caused by aripiprazole in a patient with history of schizophrenia without other precipitating factors to explain hyponatremia or SIADH.
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PMID:Aripiprazole-induced syndrome of inappropriate antidiuretic hormone secretion (SIADH). 1685 73

Although haloperidol is widely prescribed for the treatment of schizophrenia, its beneficial effects are accompanied by extrapyramidal side effects (EPS). Role of 5-HT-2A/2C receptors in the attenuation of acute Parkinsonian-like effects of typical antipsychotics is investigated by prior administration of mianserin and mesulergine to rats injected with haloperidol. In the first part of study effects of various doses of haloperidol (0.5, 1.0, 2.5 and 5.0 mg/kg) were determined on motor activity and a selected dose (1 mg/kg) was used to monitor attenuation of parkinsonian effects by two different doses of 5-HT-2A/2C receptor antagonists mianserin (2.5 & 5.0 mg/kg) and mesulergine (1.0 & 3.0 mg/kg). Rats treated with haloperidol at doses of 0.5-5.0 mg/kg exhibited impaired motor coordination and a decrease in exploratory activity in an open field. The dose response curve showed that at a dose of 1 mg/kg significant and submaximal effects are produced on motor coordination and exploratory activity. Coadministration of mianserin and mesulergine attenuated and reversed haloperidol-induced motor deficits in a dose dependent manner. The mechanism involved in the attenuation / reversal of haloperidol-induced parkinsonian like symptoms by mianserin and mesulergine is discussed. Prior administration of mianserin or mesulergine may be of use in the alleviation of EPS induced by conventional antipsychotic drugs.The findings have potential implication in the treatment of schizophrenia and motor disorders.
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PMID:Reversal of haloperidol-induced motor deficits by mianserin and mesulergine in rats. 2119 Sep 11

Treatment response to antipsychotic drugs is variable and conflicting results have been obtained while studying the influence of DRD2 and HTR2 genetic variants on antipsychotic drug efficacy. To explore further, the present study aimed to assess the influence of DRD2 -141 C Ins/Del, Taq1A and HTR2A -1438 G/A, 102T/C and HTR2C -759 C/T genetic polymorphisms in response to risperidone in patients with schizophrenia. The study was conducted among the n = 320 South Indian patients with schizophrenia who received risperidone treatment (4-8 mg per day) for a minimum of four weeks. Genotyping was done by real-time PCR. Antipsychotic response was assessed using CGI-I score in cross-sectional group, PANSS score in prospective group at baseline and after receiving the risperidone therapy. DRD2 -141 C Ins/Del (n = 310, Ins/Ins = 177, Ins/Del+ Del/Del = 133, OR 0.70, 95% CI 0.4-1.2 p 0.2), Taq1A (n = 320, AA = 35, AG = 132, GG = 153, p 0.2), HTR2A -1438 G/A (n = 320, AA = 39, AG = 164, GG = 117, p 0.2), HTR2A 102T/C (n = 320, CC = 115, CT = 165, TT = 40, p 0.1) HTR2C -759 C/T (females n = 132, CC = 65, CT+TT = 67, OR 1.3, 95% CI 0.6-2.8, p 0.5; males n = 186, C = 120, T = 66, OR 1.2, 95% CI 0.6-2.4, p 0.4) genetic polymorphisms did not show any association with antipsychotic response to risperidone. DRD2 -141 C Ins/Del, Taq1A, HTR2A -1438 G/A, 102T/C and HTR2C -759 C/T genetic variants are not associated with antipsychotic response to risperidone.
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PMID:Dopamine (DRD2) and Serotonin (HTR2A, 2C) Receptor Gene Polymorphisms do not influence early response to Risperidone in South Indian Patients with Schizophrenia. 3033 6