rs121918394
A SNP in the APOE gene on chromosome 19. Its most notable genotype is A;G: Hyperlipoproteinemia, type III
- Gene
- APOE
- Location
- Chr 1944,908,786 (GRCh38)
- Highest magnitude
- 5.0Very important
- Tested on
- Not on consumer chips
Genotypes
As shown in 23andMe and AncestryDNA files.
On SNPedia: (A;A), (A;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Related
Other APOE SNPs
- rs121918393A;ATwo copies of ApoE3 Christchurch variant (apparently)Very important
- rs267606664A;GRare ApoE1 allele; clinical significance unclearVery important
- i5000217C;Tfamilial hyperlipoproteinemia, type IIIImportant
- rs387906567C;TFamilial type 3 hyperlipoproteinemiaImportant
- rs199768005A;TMarked reduced risk of Alzheimer's DiseaseWorth knowing
- rs449647T;Tlower levels of ApoEWorth knowing
- rs429358C;Cone of 2 snps relevant to classifying APOE genotypeMinor
- rs7412C;Cpart of APOE4 genoset evaluationMinor
Notes
From SNPedia
Show notes, about 180 words
rs121918394 represents a variant in the APOE gene on chromosome 19. There are two known alternative alleles, known as c.490A>C, p.Lys164Gln or K164Q, or as c.490A>G, p.Lys164Glu or K164E, using current reference numbering. However, in older publications, this position is historically described as being amino acid 146 (not 164), and so p.Lys146Gln and p.Lys146Glu can also be found as aliases in the literature. The K164E/K146E variant has been designated ApoE1-Harrisburg according to OMIM, and is a dominant mutation leading to familial dysbetalipoproteinemia. This variant is called i6007512 by 23andMe. The K164Q/K146Q variant is also a dominant mutation leading with high penetrance to type III hyperlipoproteinemia (i.e. familial dysbetalipoproteinemia), according to OMIM, but it is reportedly observed (electrophoretically) as an E2 phenotype. Note that the first ApoE1 allele described derives from rs267606664, a variant at a different amino acid, known as c.434G>A, p.Gly145Asp or G145D, or in older numbering, p.Gly127Asp or G127D.
A;G
see links via main rs-page
Source and license
Adapted from rs121918394 on SNPedia, using a snapshot taken October 16, 2026. SNPedia content is shared under CC BY-NC-SA 3.0 US, and this page is shared under the same license.
SNPedia is a community-edited wiki. Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice. Magnitude is a community rating of how interesting a genotype is, not a risk score.