Selenium Enzyme Activity

Your result, the one DNA position behind it, and what the research says.

5/10 confidence.

About Selenium Enzyme Activity

Glutathione peroxidase 1 is one of the body's main routes for disposing of hydrogen peroxide, a by-product of ordinary metabolism. It is unusual in containing selenium at its active site, one of twenty-five human proteins built that way. This variant swaps proline for leucine and makes the enzyme somewhat less stable, so activity runs lower. Because the enzyme needs selenium to work, dietary selenium and this variant interact: neither alone tells the whole story.

Good to know: This enzyme is one of the main reasons selenium is a dietary requirement. Activity depends on both the variant and selenium supply. Several other enzymes handle the same chemistry.

Fun fact: Selenium sits at the enzyme's active site in a rare twenty-first amino acid, selenocysteine, which the body has a dedicated system to insert.

Discovery: The proline to leucine change was reported in 1994, and its frequency and its effect on enzyme activity were measured over the following decade.

The Variant

The single variant behind this trait

Gene: GPX1

Variant (rsID): rs1050450

Location: Chr 3:49,357,401

dbSNP rs1050450

The studies

Impact of single nucleotide polymorphisms (SNPs) in antioxidant-enzyme genes on the concentrations of folate, homocysteine and glutathione in plasma from healthy subjects after folic acid supplementation - a randomized controlled crossover trial (Mansoor MA et al., Genes & nutrition, 2025)

Other lifestyle traits

Adrenaline Receptor Tuning: A change in the beta-2 adrenaline receptor, the switch adrenaline uses to open airways and to make brown fat generate heat.

Telomere Length: A variant in a region linked to telomere length, the protective caps on the ends of your chromosomes.

Longevity Variant: A variant in FOXO3, one of the very few genes linked to living past 95 in study after study, across populations that share almost nothing else.

Back to All Traits

Content updated September 2026.

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