OBJECTIVE: To explore the relationship between dopamine D1 receptor gene (DRD1) and symptom quantitative trait of schizophrenia. METHODS: Peripheral blood samples were collected from 211 schizophrenics and 247 healthy controls at our center. Five tag SNPs (single nucleotide polymorphisms) (rs4532, rs5326, rs2168631, rs6882300 & rs267418) within DRD1 gene were genotyped by TaqMan SNP genotyping assay. The positive and negative syndrome scale (PANSS) was used to quantify the phenotypes of schizophrenia. RESULTS: No significant differences existed in the frequencies of genotypes and alleles of DRD1 gene between the schizophrenics and normal controls (Ps > 0.05); strong linkage disequilibrium was observed between rs4532 and rs5326 (D' = 0.84); no significant difference of haplotypic distribution was identified between the patients and controls (Ps > 0.05); the patients with rs4532G allele had a higher negative subscale score than those without G allele (20.3 ± 3.3 vs 18.2 ± 3.9, P < 0.01). CONCLUSION: The rs4532 within DRD1 gene may be associated with negative symptom quantitative trait in schizophrenia.
OBJECTIVE: To explore the relationship between dopamine D1 receptor gene (DRD1) and symptom quantitative trait of schizophrenia. METHODS: Peripheral blood samples were collected from 211 schizophrenics and 247 healthy controls at our center. Five tag SNPs (single nucleotide polymorphisms) (rs4532, rs5326, rs2168631, rs6882300 & rs267418) within DRD1 gene were genotyped by TaqMan SNP genotyping assay. The positive and negative syndrome scale (PANSS) was used to quantify the phenotypes of schizophrenia. RESULTS: No significant differences existed in the frequencies of genotypes and alleles of DRD1 gene between the schizophrenics and normal controls (Ps > 0.05); strong linkage disequilibrium was observed between rs4532 and rs5326 (D' = 0.84); no significant difference of haplotypic distribution was identified between the patients and controls (Ps > 0.05); the patients with rs4532G allele had a higher negative subscale score than those without G allele (20.3 ± 3.3 vs 18.2 ± 3.9, P < 0.01). CONCLUSION: The rs4532 within DRD1 gene may be associated with negative symptom quantitative trait in schizophrenia.