Background: Serotonin 5-HT4 receptor (HTR4) is involved in learning and memory process. The location of this gene is in schizophrenia-susceptible loci.

Objectives: This study aimed to investigate the variation in HTR4 gene in association with schizophrenia in Thai population.

Materials and Methods: A total of 75 schizophrenia patients and 170 normal controls volunteered in this study. DNAs were extracted from whole blood. The purified DNAs were amplified and genotyped by PCR using 3’-locked nucleic acid (LNA) modified SNP primers and by high resolution melting (HRM) analysis. The differences in genotype distribution between patients and controls were assessed by Chi-square test of the SPSS software version 11.5.

Results: All studied SNPs were in Hardy-Weinberg equilibrium. Two SNPs, rs2277051 and rs2277049, showed significant association with schizophrenia (p = 0.001, and p = 0.015, respectively). The genotype C of rs2277051 and G of rs2277049 existed in schizophrenia more than in control.

Conclusion: We found two SNPs in intronic region of serotonin 5-HT4 receptor gene, rs2277051 and rs2277049, that related to the susceptibility for schizophrenia in Thai population.