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Associations between catalase phenotype and genotype: modification by epidemiologic factors
Jiyoung Ahn1, Susan Nowell, Susan E McCann
1Department of Epidemiology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA.
Summary
The CAT gene polymorphism (-262C --> T) affects catalase enzyme activity, particularly in Caucasians. Dietary factors like fruit and vegetable intake modify this genotype-phenotype relationship, highlighting biochemical complexity in genetic studies.
Area of Science:
- Biochemistry
- Genetics
- Nutritional Science
Background:
- Catalase is a key antioxidant enzyme neutralizing hydrogen peroxide.
- Oxidative stress is linked to various health conditions.
- A common polymorphism in the catalase gene (CAT) promoter (-262C --> T) may influence enzyme function and disease risk.
Purpose of the Study:
- To investigate the functional impact of the CAT -262C --> T polymorphism on erythrocyte catalase activity.
- To explore how demographic and lifestyle factors modify the relationship between CAT genotype and catalase phenotype.
Main Methods:
- Analysis of erythrocyte catalase activity in 420 controls from cancer studies.
- Genotyping for the CAT -262C --> T polymorphism.
- Stratification by ethnicity, sex, and dietary intake (fruits and vegetables).
Main Results:
- A dose-response reduction in catalase activity was observed with increasing T alleles (CC > CT > TT).
- This genotype-phenotype association was significant in Caucasians but not African Americans.
- Dietary intake of fruits and vegetables modified the effect, with stronger associations in high consumers and those with T alleles.
Conclusions:
- The CAT -262C --> T polymorphism influences catalase enzyme activity, primarily in Caucasian populations.
- Dietary factors, specifically fruit and vegetable consumption, modulate the biochemical impact of this genetic variation.
- These findings underscore the complex interplay between genetics, diet, and phenotype in the context of oxidative stress.
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