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Genetic Archaeology
GENETIC ARCHAEOLOGY // PROFILE

TTPA

Alpha-Tocopherol Transfer Protein

CHR 8
8q12.3

Overview

The TTPA gene encodes the alpha-tocopherol transfer protein (alpha-TTP). It is primarily active in the liver and determines how much of the ingested Vitamin E (specifically alpha-tocopherol) enters the systemic circulation instead of being degraded or excreted.

📍 Chromosomal Position

8q12.3 (Chromosome 8)

🧬 Gene Category

Vitamins

🔬 Inheritance

Autosomal recessive / Complex

📊 Prevalence

G allele ~30-40%

Function & Significance

TTPA is the most important regulator of Vitamin E status in the body:

  • Selection: Specifically recognizes alpha-tocopherol (the most active form of Vitamin E) from various tocopherols.
  • Transport: Loads VLDL particles in the liver with Vitamin E so it can be transported to tissues (especially the brain and nervous system).
  • Prevention of Deficiency: Prevents Vitamin E from being degraded too quickly.
  • Antioxidant Protection: By providing Vitamin E, it protects cells from damage caused by free radicals.

🛡️ The Shield for Nerves

Vitamin E is one of the most important fat-soluble antioxidants. Without a functioning TTPA gene, however, very little Vitamin E reaches the body, even if enough is taken in through food. This is particularly critical for the nervous system, as nerve cells are highly sensitive to oxidative stress.

🧬 Relevant SNPs

Common variants such as rs6994076 influence basal Vitamin E levels:

rs6994076
8:63186241
Allele 1

A

/

Allele 2

G

Significance: rs6994076 (A>G) – Statistical association with Vitamin E levels.

• AA (Wild type): Normal transfer efficiency.

• GG / AG: Carriers of the G allele often exhibit lower plasma concentrations of alpha-tocopherol in studies.

⚠️ Increased Requirement

Variants in the TTPA gene can lead to lower Vitamin E levels despite a ‘normal’ diet. Under high stress (smoking, intensive sports, inflammation), oxidative stress can then lead to cell damage more quickly.

🥑 Natural Vitamin E Sources

To support Vitamin E status, the following foods are particularly valuable: wheat germ oil, sunflower seeds, almonds, hazelnuts, and avocados. Vitamin E should always be consumed with some fat.

📚 Data Sources

  • OMIM: #600415 – Online Mendelian Inheritance in Man
  • dbSNP: rs6994076 – SNP Database (NCBI)
  • Free Radical Biology and Medicine: TTPA function and Vitamin E metabolism
  • American Journal of Clinical Nutrition: Genetic variation in Vitamin E status

Last Update: February 2026

Biological Function

The TTPA protein binds alpha-tocopherol (the most active form of Vitamin E) in the liver and facilitates its incorporation into VLDL particles for transport to tissues. Mutations or variants can lead to low plasma Vitamin E levels.

Associated Conditions

Ataxia with Vitamin E Deficiency (AVED) Degenerative Diseases Increased Oxidative Stress
Molecular Analysis

Analyzed Markers

rs6994076 Risk Factor
Pos: 8:63186241 | Alleles: A/G

rs6994076 - G-allele: Associated with lower blood alpha-tocopherol levels and potentially increased Vitamin E requirement for protection against oxidative stress.