rs121917967
A SNP in the SCN1A gene on chromosome 2. Its most notable genotype is A;T: Dravet syndrome and severe epileptic seizure syndrome(s) possible
- Gene
- SCN1A
- Location
- Chr 2166,046,910 (GRCh38)
- Highest magnitude
- 8.0Very important
- Tested on
- AncestryDNA
Genotypes
Plus strand, as in 23andMe and AncestryDNA files.
- A;TMost notableBadDravet syndrome and severe epileptic seizure syndrome(s) possible
- A;AGoodcommon/normal
SNPedia records rs121917967 on the minus strand: (A;T), (T;T). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Related
Conditions, medicines and genes
Notes
From SNPedia
Show notes, about 150 words
rs121917967, also known as c.1237T>A, p.Tyr413Asn and Y413N, represents a very rare variant in the SCN1A gene on chromosome 2. This mutation is reported in at least two publications as leading to Severe myoclonic epilepsy in infancy (SMEI), also known as Dravet syndrome and epileptic encephalopathy, all of which are inherited dominantly although they can and do arise from de novo mutations as well. Note that this mutation is the basis of the Williams v Quest/Athena case, in which a mother accuses Athena of misclassifying this mutation (in her infant son, who eventually died of complications following a seizure) as a variant of unknown significance (VUS) rather than as disease-causing.wp.genewhisper.com
A;T
Originally classified as a variant of unknown significance (VUS); more recently considered likely to be pathogenic. See discussion at rs121917967.
Source and license
Adapted from rs121917967 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.