Decreased paraoxonase-1 (PON1) activity has been associated with rheumatoid arthritis. There are two polymorphisms in serum PON1; one differs in the amino acid at position 192 (Q192R) and the other one differs at position 55 (L55M). We looked for a possible association between Q192R polymorphism and rheumatoid arthritis. The Q192R polymorphism in 88 rheumatoid arthritis patients and 78 healthy subjects was determined using tetra amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and PCR-restriction fragment length polymorphism (RFLP) methods. We found no significant differences between rheumatoid arthritis patients and control subjects regarding PON1 Q192R polymorphism. PON1 Q192R polymorphism was not found to be correlated with increased risk for rheumatoid arthritis in this Iranian population.

Objective Schizophrenia (SCZ) is a type of psychotic disorder that affects ∼1% of the population. Dopamine is one of the major neurotransmitters in the brain and its receptors are associated with a number of psychotic disorders, including SCZ. The aims of the present study were to analyze methylation and the expression profile of dopamine receptor DRD1, DRD2, DRD4, and DRD5 genes in patients with SCZ. Materials and methods Promoter methylation of DRD1, DRD2, DRD4, and DRD5 genes was assayed by a methylation-specific PCR in blood samples obtained from 80 SCZ cases and 71 healthy controls. Also, we investigated DRD1, DRD2, DRD4, and DRD5 mRNA levels using real-time reverse transcription PCR in 34 blood samples of healthy controls and cases. Results Promoter methylation of DRD4, DRD5, and DRD2 genes was statistically different in cases compared with healthy controls. The mRNA expression level results also showed statistically significant differences (P<0.0001) between cases and healthy controls for the DRD2, DRD4, and DRD5 genes, but not for DRD1. Conclusion Analyses of DRD genes’ methylation have highlighted the fact that the DRD gene network, overall, is actively involved in the increased risk of SCZ.

Paraoxonase-1 (PON1) is a high-density lipoprotein-associated enzyme that exhibits antioxidant and antiatherogenic activities. We examined a possible association between T172A (L55M) and T(-107)C polymorphisms and rheumatoid arthritis. These polymorphisms were determined in 88 rheumatoid arthritis patients and 78 healthy subjects, using the tetra-amplification refractory mutation system-PCR method. The prevalence of the PON1 55MM genotype was significantly greater among rheumatoid arthritis patients (17%) when compared to control subjects (5.2%) (odds ratio (OR) = 3.75; 95% confidence interval (CI) = 1.87-11.8, P = 0.025). In addition, the M allele was more frequent in rheumatoid arthritis patients (40%) than in healthy subjects (24.7%) (OR = 1.997; 95%CI = 1.243-3.210, P = 0.005). There were no significant differences in the -107C/T polymorphism in the promoter sequence of PON1 between rheumatoid arthritis and normal subjects (chi(2) = 0.861, P = 0.650). In conclusion, the PON1 55MM genotype is a risk factor for rheumatoid arthritis.