rs121907981

A SNP in the HEXA gene on chromosome 15. Its most notable genotype is G;G: Tay-Sachs disease (predicted)

Gene
HEXA
Location
Chr 1572,345,550 (GRCh38)
Highest magnitude
8.8Very important
Tested on
AncestryDNA

Genotypes

Plus strand, as in 23andMe and AncestryDNA files.

  1. G;GMost notableBadTay-Sachs disease (predicted)Very important · 8.8
  2. C;GBadCarrier of a Tay-Sachs mutationImportant · 3.0
  3. C;CGoodcommon in clinvarTypical · 0.0

SNPedia records rs121907981 on the minus strand: (C;C), (C;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.

Conditions, medicines and genes

Other HEXA SNPs

All HEXA SNPs

Notes

From SNPedia

Notes

G;G

see discussion at Tay-Sachs disease.

C;G

Unaffected in absence of a second HEXA gene mutation; see discussion at Tay-Sachs disease.

Source and license

Adapted from rs121907981 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.