rs267606858
A SNP in the GYG1 gene on chromosome 3. Its most notable genotype is T;T: Likely miscall in DNA-chip based data, such as that from Ancestry or 23andMe; otherwise, Glycogen storage disease XV
- Gene
- GYG1
- Location
- Chr 3148,996,406 (GRCh38)
- Highest magnitude
- 5.0Very important
- Tested on
- 23andMe, AncestryDNA
Genotypes
As shown in 23andMe and AncestryDNA files.
- C;CGoodcommon in clinvar
- C;TBadLikely miscall in DNA chip data, such as that from Ancestry or 23andMe; otherwise, carrier of a glycogen storage disease mutation
- T;TMost notableBadLikely miscall in DNA-chip based data, such as that from Ancestry or 23andMe; otherwise, Glycogen storage disease XV
On SNPedia: (C;C), (C;T), (T;T). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Notes
From SNPedia
Show notes, about 130 words
rs267606858, also known as c.248C>T, p.Thr83Met and T83M, represents a very rare mutation in the GYG1 gene on chromosome 3. The rs267606858(T) mutation is considered pathogenic for glycogen storage disease XV, a recessively inherited disease, based on data in ClinVar and OMIM. All DNA chip-based direct-to-consumer tests that we (SNPedia/Promethease) know about, such as those from Ancestry or 23andMe, appear to have a very high false-positive error rate for this SNP.
C;T
Likely miscall in Ancestry and 23andMe data. When properly called, this genotype represents an unaffected carrier so long as there isn't another GYG1 mutation; see discussion at rs267606858
T;T
Likely miscall in data from companies such as Ancestry or 23andMe. See discussion and links at rs267606858
Source and license
Adapted from rs267606858 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.