i4000440

A SNP in the HEXA gene on chromosome 15. Its most notable genotype is A;A: likely to lead to a false positive blood test for Tay Sachs disease

Gene
HEXA
Location
Chr 1572,642,919 (GRCh38)
Highest magnitude
2.0Worth knowing
Tested on
23andMe

Genotypes

As shown in 23andMe and AncestryDNA files.

  1. A;AMost notableBadlikely to lead to a false positive blood test for Tay Sachs diseaseWorth knowing · 2.0
  2. A;GBadlikely to lead to a false positive blood test for Tay-Sachs DiseaseWorth knowing · 2.0
  3. G;GGoodnormalTypical · 0.0

On SNPedia: (A;A), (A;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.

Other HEXA SNPs

All HEXA SNPs

Notes

From SNPedia

Show notes, about 230 words

This SNP is associated with a change in the protein encoded by the HEXA gene, which leads to a false positive blood test for Tay-Sachs Disease. In other words, the blood test from an individual with an i4000440(A) allele will indicate the person is a carrier for Tay Sachs disease, even though this SNP is not actually one that leads to the disease. Note however that the person may still carry (on their other chromosome 15) a "true" Tay Sachs causing allele. rs138058578

A;A

This SNP is associated with a change in the protein encoded by the HEXA gene, which leads to a false positive blood test for Tay-Sachs Disease. In other words, the blood test from an individual with this genotype will indicate the person is a carrier for Tay Sachs disease, even though this SNP is not actually one that leads to the disease. Note however that the person may still carry (on their other chromosome 15) a "true" Tay Sachs causing allele.

A;G

This SNP is associated with a change in the protein encoded by the HEXA gene, which leads to a false positive blood test for Tay-Sachs Disease. In other words, the blood test from an individual with this genotype will indicate the person is a carrier for Tay Sachs disease, even though this SNP is not actually one that leads to the disease. Note however that the person may still carry (on their other chromosome 15) a "true" Tay Sachs causing allele.

Source and license

Adapted from i4000440 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.