HTR2A

Chr 13AD

5-hydroxytryptamine receptor 2A

Also known as: 5-HT2A, HTR2

NCBI Gene: 3356ENSG00000102468UniProt: P28223OMIM: 182135

This gene encodes one of the receptors for serotonin, a neurotransmitter with many roles. Mutations in this gene are associated with susceptibility to schizophrenia and obsessive-compulsive disorder, and are also associated with response to the antidepressant citalopram in patients with major depressive disorder (MDD). MDD patients who also have a mutation in intron 2 of this gene show a significantly reduced response to citalopram as this antidepressant downregulates expression of this gene. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2009]

GeneReviewsOMIMResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

{Major depressive disorder, response to citalopram therapy in}MIM #608516
{Obsessive-compulsive disorder, susceptibility to}MIM #164230
AD
{Schizophrenia, susceptibility to}MIM #181500
AD

Clinical highlights

Interpreting a novel variant
This gene is strongly intolerant of loss-of-function variation in the population, so LoF variants warrant close attention. No curated mechanism annotation is available — see the mechanism card for the computational prediction and its caveats.Based on population constraint only.
4
Active trials
124
Pubs (1 yr)
—
P/LP submissions
—
P/LP missense
0.52
LOEUF
Multiple*
Mechanism· predicted
📖
GeneReview available — HTR2A
Authoritative clinical overview · Recommended first read
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Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
Moderate LoF intolerance
LoF Constraint?
0.52LOEUF
pLI 0.511
Z-score 2.86
OE 0.20 (0.09–0.52)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint?
1.75Z-score
OE missense 0.69 (0.61–0.78)
177 obs / 255.7 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?
LoF OE?0.20 (0.09–0.52)
0≤0.351.4
Missense OE?0.69 (0.61–0.78)
0≤0.61.4
Synonymous OE?1.02
0≤1.21.6
LoF obs/exp: 3 / 14.9Missense obs/exp: 177 / 255.7Syn Z: -0.15

ClinVar Variant Classifications

0 submitted variants in ClinVar

ClinVar

Protein Context — Lollipop Plot

HTR2A · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

External Resources

Links to major genomics databases and tools

Franklin by Genoox
AI-powered variant curation and clinical analysis
DECIPHER
Genomic variants and phenotypes in rare disease patients