SLC19A1
The solute carrier family 19 member 1 (SLC19A1) protein, encoded by the SLC19A1 gene, transports the vital nutrient folate into an out of the cell and thus plays a role in the intracellular regulation of folate concentrations 1. SLC19A1 is a major folate transportr and therefore is universally expressed in all tissues of the body 1.
Folate is required for the production of new cells, through the production and maintenance of DNA and to modulate expression of genes via DNA methylation 2. It is therefore especially important during periods of rapid cell division such as during pregnancy of infancy, but is also important for rapidly dividing tissues such as blood cells and cells of the immune system 3.
Dietary folate is the precursor molecule which enters the one carbon cycle, which forms part of the wider methylation cycle. The rate limiting enzyme in this cycle is the well-researched methylenetetrahydrofolate reductase (MTHFR), and so SNPs in SLC19A1 are often discussed in conjunction with those of MTHFR.
There is one SNP in the SLC19A1 gene which is associated with poor health outcomes, rs1051266 or A80G.
| rsID Number | Major Allele | Minor Allele | Minor Allele Frequency (%) | Major Amino Acid | Minor Amino Acid |
|---|---|---|---|---|---|
| rs1051266 | g | a | 42 | His | Arg |
Risk Description
The risk allele ‘A’ of the SNP rs1051266 or A80G in the SLC19A1 gene is associated with increased homocysteine levels in the blood 4,5. Elevated homocysteine can be very damaging to tissue, particularly the specialized endothelial tissue which lines the blood vessels and heart. As such it is associated with increased cardiovascular risks 6 along with various neurological issues 7.
Although the risk allele ‘A’ is associated with elevated homocysteine no direct health impacts have been described. Suggesting that the risk ‘A’ allele of A80G in SLC19A1 may not be sufficient alone to drive adverse health outcomes. However, an effect may be observed when present in conjunction with other SNPs such as the risk ‘T’ allele of C667T in the MTHFR gene.
Indirect Nutrients:*
| Ingredient | Active Ingredient | Effect |
|---|---|---|
| Vitamin B12 | Methylcobalamin |
Vitamin B12 is a cofactor for methionine synthase which converts the harmful homocysteine into the essential acid methionine 8. Those carrying the risk allele ‘A’ of A80G may benefit from vitamin B12 supplementation, to ensure methionine synthase activity thus preventing the accumulation of homocysteine. |
| Betaine | Trimethylglycine |
Betaine serves as a methyl donor in the conversion of the harmful homocysteine into the essential acid methionine by the enzyme betaine-homocysteine S-methyltransferase (BHMT) 9. Those carrying the risk allele ‘A’ of A80G, which is associated with elevated homocysteine, may benefit from betaine supplementation to maximise BHMT activity. |
Discuss this information with your doctor before taking any course of action.
Citations:
- https://www.ncbi.nlm.nih.gov/pubmed/9570943
- https://www.ncbi.nlm.nih.gov/pubmed/9420019
- https://www.ncbi.nlm.nih.gov/pubmed/26334606
- https://www.ncbi.nlm.nih.gov/pubmed/24524080
- https://www.ncbi.nlm.nih.gov/pubmed/18842806
- https://www.ncbi.nlm.nih.gov/pubmed/10063987
- https://www.ncbi.nlm.nih.gov/pubmed/12849121
- https://www.ncbi.nlm.nih.gov/pubmed/22116707
- https://www.ncbi.nlm.nih.gov/pubmed/17086380