rs1154155
A SNP in the TRA gene on chromosome 14. Its most notable genotype is G;G: 2.5x increased risk for narcolepsy
- Gene
- TRA
- Location
- Chr 1422,533,736 (GRCh38)
- Highest magnitude
- 2.5Worth knowing
- Tested on
- 23andMe, AncestryDNA
- Minor allele frequency
- 24%
Genotypes
As shown in 23andMe and AncestryDNA files.
- G;GMost notableBad2.5x increased risk for narcolepsy
- G;TBad1.94x increased risk for narcolepsy
- T;TGoodnormal
On SNPedia: (G;G), (G;T), (T;T). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Frequency
Share of each genotype in 11 HapMap populations.
- AverageG;G 8% G;T 29% T;T 63%
- European ancestry (Utah)G;G 3% G;T 24% T;T 74%
- Han Chinese (Beijing)G;G 27% G;T 50% T;T 23%
- Japanese (Tokyo)G;G 25% G;T 47% T;T 28%
- Yoruba (Nigeria)G;G <1% G;T 8% T;T 92%
- African ancestry (Southwest US)G;G 0% G;T 16% T;T 84%
- Chinese (Denver)G;G 28% G;T 51% T;T 21%
- Gujarati IndianG;G 3% G;T 25% T;T 72%
- Luhya (Kenya)G;G 0% G;T 7% T;T 93%
- Mexican ancestry (Los Angeles)G;G 0% G;T 40% T;T 60%
- Maasai (Kenya)G;G <1% G;T 17% T;T 83%
- TuscanG;G 4% G;T 33% T;T 63%
Related
Conditions, medicines and genes
Notes
From SNPedia
Show notes, about 180 words
rs1154155 is a SNP in the TCRA T-cell receptor alpha gene. The minor allele is (G). A study of 1,830 people with narcolepsy and cataplexy (a sudden loss of muscle tone that can cause people to collapse) compared to 2,164 healthy controls concluded that several SNPs in the TCRA gene were linked. The most significant association was with this SNP, rs1154155, with an average allelic odds ratio of 1.69 (genotypic odds ratios 1.94 and 2.55, p < 10e-21). Note the following, though, as quoted from a Science News article: "Even with all of the known genetic risk factors, including the newly discovered version of the T cell receptor gene, a person has only a 1.5 percent chance of developing narcolepsy.... That suggests that, while narcolepsy is probably an autoimmune disorder, further genetic and environmental triggers and risk factors remain to be found." HLA-DQB1*0602 and relevance to Narcolepsy related to vaccination A study of 500+ Chinese patients with narcolepsy confirms that narcolepsy is strongly and dose dependently associated with rs1154155(G) in this population.
Source and license
Adapted from rs1154155 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.