Polymorphisms of glutathione peroxidase 1 (GPX1 Pro198Leu) and catalase (CAT C-262T) in women with spontaneous abortion.

About 10%-15% of conceptions are lost spontaneously prior to 20 weeks. Apart from the clinical problems, genetic variations have also been proposed as a susceptibility factor to miscarriage. Glutathione peroxidase 1 (GPX1) and catalase (CAT) encode two antioxidant enzymes that detoxify H2O2 and protect the cells from oxidative damage. A functional polymorphism at codon 198 of the GPX1 gene causes a C/T substitution in exon 2, which encodes for either proline or leucine (Pro198Leu). The CAT gene has a polymorphic site in the promoter region at position -262 (C-262T) which alters the expression and enzyme blood levels, leading to some pathological clinical conditions. In this study, we evaluated the association of these two polymorphisms with the risk of spontaneous abortion. Genomic DNA from 105 cases with spontaneous abortion and 90 healthy women were genotyped using allele-specific PCR (AS-PCR) and polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP). The genetic distributions for GPX1 did not differ significantly between cases and controls (p = 0.680). However, C-262T polymorphism was significantly associated with the risk of the disease (OR, 5.50; 95% CI, 1.43-21.09; p = 0.012). In conclusion, this study indicates that CAT -262T/T genotype confers less susceptibility to spontaneous abortion, while GPX1 Pro198Leu polymorphism may not be correlated with the disease.

Catalase gene C-262T polymorphism: importance in ulcerative colitis.

BACKGROUND AND AIM: Reactive oxygen species (ROS) are by-products of the cellular metabolism and have important roles in the normal physiology of the cell. However, when ROS production exceeds the antioxidant capacity, a state known as oxidative stress, damage to cellular macromolecules emerges. A crucial role in counteracting ROS is played by the enzyme catalase. A common polymorphism in the catalase (CAT) promoter region (C-262T) alters the expression as well as blood catalase levels, and leads to a number of human diseases. Ulcerative colitis (UC) is an inflammatory condition of the large bowel that is known to be influenced by oxidative stress. In this study, we aimed to evaluate the association of CAT C-262T polymorphism on the risk of UC. METHODS: Samples were collected from 60 patients diagnosed with UC and 78 control subjects, and genotyped by allele-specific polymerase chain reaction. RESULTS: We found that CAT C-262T genotype frequencies were significantly different between cases and controls (P = 0.002). Individuals carrying the -262C/T genotype had a greater risk for UC compared with C/C genotype (odds ratio, 4.88; 95% confidence interval, 1.73-13.75, P = 0.002). CONCLUSIONS: This study indicates that CAT C-262T polymorphism may be associated with UC, and that the -262C/T genotype may be a risk factor for the disease. Further studies are needed to confirm the results.