rs7997012
A SNP in the HTR2A gene on chromosome 13. Its most notable genotype is A;A: ~18% more likely to respond to citalopram
- Gene
- HTR2A
- Location
- Chr 1346,837,850 (GRCh38)
- Highest magnitude
- 0.0Typical
- Tested on
- 23andMe, AncestryDNA, FamilyTreeDNA
- Minor allele frequency
- 27%
Genotypes
As shown in 23andMe and AncestryDNA files.
- A;AMost notableGood~18% more likely to respond to citalopram
- A;GNot ratednormal risk
- G;GBad~18% less likely to respond to citalopram
On SNPedia: (A;A), (A;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Frequency
Share of each genotype in 4 HapMap populations.
- AverageA;A 6% A;G 28% G;G 66%
- European ancestry (Utah)A;A 10% A;G 52% G;G 39%
- Han Chinese (Beijing)A;A 13% A;G 29% G;G 58%
- Japanese (Tokyo)A;A 0% A;G 32% G;G 68%
- Yoruba (Nigeria)A;A 0% A;G 0% G;G 100%
Related
Conditions, medicines and genes
Other HTR2A SNPs
- rs6311C;C3.6x increased risk of sexual dysfunction when taking SSRI Antidepressants.Important
- rs6313A;Adepression, panic, stress responseWorth knowing
- rs6314G;Ghigher risk for RATypical
- rs594242C;GNo summary available.Typical
- rs643627A;GNo summary available.Typical
- rs659734A;Acommon in complete genomicsTypical
- rs1328674T;Thigher risk for RATypical
- rs2224721G;Gcommon/normalTypical
Notes
From SNPedia
Notes
rs7997012, located in an intron of the HTR2A gene, was found to be associated with a somewhat increased rate of successful response to treatment of depression with the drug citalopram. From this article : "HTR2A encodes the serotonin 2A receptor, which is downregulated by citalopram. Participants who were homozygous for the A allele had an 18% reduction in absolute risk of having no response to treatment, compared with those homozygous for the other allele." * See also Anxiety Blog posting
Source and license
Adapted from rs7997012 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.