rs1001179 — CAT -262C>T

Catalase — Your Body's Hydrogen Peroxide Defense

Catalase is one of the most efficient enzymes in nature, breaking down millions of hydrogen peroxide molecules per second into harmless water and oxygen. Located primarily in cellular structures called peroxisomes¹¹ peroxisomes
small organelles that produce and break down reactive oxygen species, catalase serves as the final defense against hydrogen peroxide accumulation. The rs1001179 variant sits 262 base pairs upstream of the catalase gene's start site, in a region that controls how much catalase your cells produce.

The Mechanism

This promoter variant changes a single DNA letter from C to T, which fundamentally alters how transcription factors bind to the catalase gene. The T allele creates a new binding site for STAT4, a transcription factor that enhances gene expression²² The T allele creates a new binding site for STAT4, a transcription factor that enhances gene expression
Forsti et al. Genetic polymorphisms in the promoter region of catalase gene, creates new potential PAX-6 and STAT4 response elements. Scientific Reports, 2017, while the C allele maintains a binding site for TFII-I, a different transcription factor.

The paradox: studies show conflicting results about which allele produces more catalase. Some research indicates the T allele increases catalase mRNA levels approximately 2-fold³³ T allele increases catalase mRNA levels approximately 2-fold
Khan et al. Influence of A-21T and C-262T genetic polymorphisms at the promoter region of the catalase (CAT) on gene expression. Free Radical Research, 2016, suggesting higher promoter activity. However, population studies consistently show that carriers of the TT genotype have worse clinical outcomes⁴⁴ carriers of the TT genotype have worse clinical outcomes
Goth et al. Association of the Common Catalase Gene Polymorphism rs1001179 With Glycated Hemoglobin and Plasma Lipids in Hyperlipidemic Patients. Biochemical Genetics, 2016 — higher blood sugar, elevated triglycerides, and increased cancer risk. This suggests that despite potentially higher baseline expression, the T allele may impair catalase function or regulation under oxidative stress conditions.

The Evidence

Cancer risk: The strongest evidence comes from a meta-analysis of 37 studies including 14,942 cancer patients and 43,285 controls⁵⁵ meta-analysis of 37 studies including 14,942 cancer patients and 43,285 controls
Zhou et al. Two common functional catalase gene polymorphisms (rs1001179 and rs794316) and cancer susceptibility. Oncotarget, 2016. The TT genotype increased overall cancer risk by 19% (OR = 1.19, P < 0.001) in the recessive model. The effect was most pronounced for prostate cancer, where TT carriers faced a 57% increased risk (OR = 1.57, P = 0.00) compared to CC genotype. No significant associations emerged for breast, colorectal, or hepatocellular carcinoma.

Metabolic dysfunction: In patients with high cholesterol, the TT genotype was associated with elevated HbA1c and plasma triglycerides⁶⁶ the TT genotype was associated with elevated HbA1c and plasma triglycerides
Goth et al. Association of the Common Catalase Gene Polymorphism rs1001179 With Glycated Hemoglobin and Plasma Lipids in Hyperlipidemic Patients. Biochemical Genetics, 2016, with the effect modulated by BMI and age. A separate study found effects on blood catalase activity and carbohydrate/lipid biomarkers in diabetes⁷⁷ effects on blood catalase activity and carbohydrate/lipid biomarkers in diabetes
Goth et al. Effects of rs769217 and rs1001179 polymorphisms of catalase gene on blood catalase, carbohydrate and lipid biomarkers in diabetes mellitus. Free Radical Research, 2012.

Oxidative stress markers: Russian population studies showed that TT genotype carriers had lower levels of diene conjugates⁸⁸ TT genotype carriers had lower levels of diene conjugates
Kozhevnikova et al. Oxidative Stress and Catalase Gene. Bulletin of Experimental Biology and Medicine, 2016, markers of lipid peroxidation, compared to CC and CT genotypes. The -262T allele frequency was 28% in Russians but only 17% in Buryats, demonstrating substantial population variation.

Inflammatory disease: The rs1001179 polymorphism has been studied in chronic hepatitis C and ulcerative colitis⁹⁹ chronic hepatitis C and ulcerative colitis
Drozdov et al. Catalase gene rs1001179 polymorphism and oxidative stress in patients with chronic hepatitis C and ulcerative colitis. Russian Journal of Gastroenterology, Hepatology, Coloproctology, 2015, with the A (T) allele showing significant correlation with antioxidants enzyme synthesis patterns, suggesting it may affect regulation of the antioxidants system under inflammatory stress.

No effect on male infertility: Despite catalase's importance for sperm protection, a genetic association study found no link between rs1001179 and male infertility¹⁰¹⁰ a genetic association study found no link between rs1001179 and male infertility
Jafari et al. Variation of the genes encoding antioxidants enzymes SOD2, GPX1, and CAT and susceptibility to male infertility. Environmental Science and Pollution Research, 2023, in contrast to significant associations with SOD2 and GPX1 variants.

Practical Actions

Catalase is a heme-containing enzyme, meaning it requires iron at its core. Unlike other antioxidants enzymes that can be supported through supplementation (glutathione, SOD mimetics), there are no direct catalase supplements with proven efficacy. The strategy is to support the broader antioxidants defense network and reduce oxidative burden.

Antioxidant support: Vitamins C and E work synergistically with catalase¹¹¹¹ Vitamins C and E work synergistically with catalase
Role of Catalase in Oxidative Stress- and Age-Associated Degenerative Diseases. Oxidative Medicine and Cellular Longevity, 2019. Vitamin C can help preserve catalase activity by maintaining enzyme integrity, while vitamin E protects cell membranes and proteins (including catalase) from oxidative damage.

Reduce oxidative burden: Lifestyle factors matter significantly for TT carriers. Heavy alcohol consumption overwhelms catalase capacity, as the enzyme is involved in metabolizing ethanol-derived hydrogen peroxide. One study found higher frequency of the T allele in Caucasian patients with alcohol use disorder¹²¹² higher frequency of the T allele in Caucasian patients with alcohol use disorder
Xu et al. Alcohol-Induced Oxidative Stress and the Role of Antioxidants in Alcohol Use Disorder. Antioxidants, 2022, though results are mixed across populations. Smoking generates substantial oxidative stress that demands high catalase activity.

Diet and metabolic control: For TT carriers with elevated HbA1c or triglycerides, standard metabolic interventions become especially important. Dietary antioxidants including polyphenols, vitamins, and minerals support endogenous antioxidants enzymes¹³¹³ Dietary antioxidants including polyphenols, vitamins, and minerals support endogenous antioxidants enzymes
Dietary Antioxidants and Chronic Diseases. International Journal of Molecular Sciences, 2023. Coffee, tea, colorful fruits and vegetables, nuts, and seeds provide concentrated antioxidants compounds.

Cancer screening: The prostate cancer association is strong enough to warrant consideration. TT carriers, particularly those with other risk factors (family history, African ancestry), should discuss appropriate screening intervals with their physician.

Interactions

Catalase works as part of a coordinated antioxidants defense system. Superoxide dismutase (SOD2, rs4880) converts superoxide radicals to hydrogen peroxide, which catalase then breaks down¹⁴¹⁴ Superoxide dismutase (SOD2, rs4880) converts superoxide radicals to hydrogen peroxide, which catalase then breaks down
Forman et al. First line defence antioxidants—superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX): Their fundamental role in the entire antioxidants defence grid. Alexandria Journal of Medicine, 2017. Glutathione peroxidase (GPX1, rs1050450) provides a parallel pathway for clearing hydrogen peroxide using glutathione as a cofactor. The related catalase variant rs794316 affects a different region of the gene and has also been studied in cancer risk meta-analyses.

When multiple antioxidants enzyme variants co-occur — for example, reduced-function alleles in both SOD2 and CAT — the oxidative burden increases synergistically. This may partly explain why genetic studies of obesity and metabolic syndrome find that polymorphisms in SOD2, CAT, and GPX1 together modulate oxidative stress markers¹⁵¹⁵ polymorphisms in SOD2, CAT, and GPX1 together modulate oxidative stress markers
Vazquez-Carrera et al. Genetic Variants in Antioxidant Genes Modulate the Relationships Among Obesity-Related Oxidative Stress Markers. Antioxidants, 2024.

The methylation cycle indirectly affects catalase function: poor methylation capacity can impair synthesis of glutathione, which competes with catalase for hydrogen peroxide detoxification. See rs1801133 (MTHFR C677T) for methylation effects on the broader antioxidants system.