The Association Between -697C>G and -997G>A polymorphism of the HTR2C Gene and the Metabolic Syndrome in Iraqi Schizophrenic Patients

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Zinah Abdulhameed Alobaidi
Samer Imad Mohammed


Olanzapine, Genetic polymorphism, -697C>G , -997G>A ,Schizophrenic patients,5-hydroxytryptamine 2C receptor (HTR2C) gene


Background: Serotonin 2C receptor (5-HT2C) antagonisms play a role in the metabolic adverse effects induced by olanzapine treatment of schizophrenic patients.
Objectives: This study aimed to determine if there is an association between the genetic polymorphisms of -697G/C and -997G>A in the promoter region of the 5-hydroxytryptamine 2C receptor (HTR2C) gene and olanzapine-induced metabolic syndrome in patients with schizophrenia.
Patients and Methods: A cross-sectional study involving 50 hospitalized patients (28 males, 22 females, mean age: 47.60 years with schizophrenia. The patients were divided into two groups according to metabolic syndrome classification criteria. Following polymerase chain reaction amplification of the extracted deoxyribonucleic acid, sequencing by the Sanger method was performed to identify the polymorphism at the HTR2C promoter region.
Results: Olanzapine significantly increases the waist circumferences and body mass index in the metabolic syndrome group (P value 0.001). The GG genotype and G allele of the -697C>G were significantly present in the metabolic syndrome group. The study failed to find any association between the genotypes of -997G>A and the tendency to have metabolic syndrome.
Conclusion: The presence of the GG genotype or G allele in the -697C>G variant was significantly associated with the metabolic syndrome group. None of the -997G>A genotypes were associated with an increased risk of developing metabolic syndrome.

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