The Alpha-Tocopherol Transfer Protein (TTPA) gene is associated with the synthesis of alpha-tocopherol transfer protein, a fat-soluble antioxidant that is secreted by the liver, together with low-density lipoproteins into the bloodstream. Variants of this gene are associated with an increase or decrease in the level of Alpha-Tocopherol Transfer Protein, which corresponds to an increase or decrease in the level of vitamin E in the body. When alterations in the gene for alpha-tocopherol transfer protein lead to its deficiency deficiency, it is associated with infertility, neurological disorders, and muscular weakness.
This vitamin is fat-soluble which is essential for a healthy immune system, skin, and eyes. As it is a good anti-oxidant, it can lower the risk of cardiovascular disease. In humans, 40 mg/kg of vitamin E is normally present, with 77% in the adipose tissue, 20% in muscle and only 1% in the liver. People on a low-fat diet are also at an increased risk for its deficiency.
In a study by researchers from the Vanderbilt and Northwestern University, 652 children and their mothers were studied for the first two years. Mothers with low levels of alpha-tocopherol were shown to be associated with an increased risk of having babies with asthma.
Does your 23andme, Ancestry DNA, FTDNA raw data have TTPA gene variant information?
| CHIP Version | TTPA SNPs |
| 23andMe (Use your 23andme raw data to know your TTPA Variant) | |
| v1 23andme | Present |
| v2 23andme | Present |
| v3 23andme | Present |
| v4 23andme | Present |
| V5 23andme (current chip) | Present |
| AncestryDNA (Use your ancestry DNA raw data to know your TTPA Variant) | |
| v1 ancestry DNA | Present |
| V2 ancestry DNA (current chip) | Present |
| Family Tree DNA (Use your FTDNA raw data to know your TTPA Variant) | |
| OmniExpress microarray chip | Present |
Association with Vitamin E Needs:
In a study conducted on 500 people from the Mediterranean population, people with the A variant of the gene were shown to be significantly associated with lower plasma levels of this vitamin.
In a similar study conducted on 449 people, there was an association between alpha-tocopherol, when supplement users were excluded. This study indicates that the lowered production of the protein that leads to lower alpha-tocopherol levels can be modified by the intake of supplements.
| Genotype rs6994076 | Phenotype | Recommendation |
| AA | [Limitation] More likely to have lower plasma Vitamin E levels | Likely decrease in plasma vitamin E levels Include grapeseed oil, flaxseed oil, sunflower oil, and canola oil in your diet to increase vitamin E levels in the body. Since there is a genetic predisposition for lower levels of vitamin E, it is recommended to take 10mg of vitamin E/day for men and 7mg/day for women |
| AT | Moderate plasma Vitamin E levels | Likely decrease in plasma vitamin E levels Include grapeseed oil, flaxseed oil, sunflower oil, and canola oil in your diet to increase vitamin E levels in the body. Since there is a genetic predisposition for lower levels of vitamin E, it is recommended to take 10mg of vitamin E/day for men and 7mg/day for women |
| TT | [Advantage] More likely to have higher plasma Vitamin E levels | Increased likelihood for normal level of plasma vitamin E levels if the dietary intake is sufficient |
References:
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1136412/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3566896/
“Nutrigenetics, fitness genetics, health genetics are all nascent but rapidly growing areas within human genetics. The information provided herein is based on preliminary scientific studies and it is to be read and understood in that context.”
