HTR3D

Chr 3

5-hydroxytryptamine receptor 3D

Also known as: 5HT3D

The protein encoded this gene belongs to the ligand-gated ion channel receptor superfamily. This gene encodes subunit D of the type 3 receptor for 5-hydroxytryptamine (serotonin), a biogenic hormone that functions as a neurotransmitter, a mitogen and a hormone. This hormone has been linked to neuropsychiatric disorders, including anxiety, depression, and migraine. Serotonin receptors causes fast and depolarizing responses in neurons following activation. The genes encoding subunits C, D and E of this type 3 receptor form a cluster on chromosome 3. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2009]

OMIMResearchGenerating clinical summary…
MultiplemechanismLOEUF 1.26
Clinical SummaryHTR3D
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
74 VUS of 92 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint?
1.26LOEUF
pLI 0.000
Z-score 0.77
OE 0.79 (0.521.26)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?
0.65Z-score
OE missense 0.88 (0.790.99)
226 obs / 255.4 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?
LoF OE?0.79 (0.521.26)
00.351.4
Missense OE?0.88 (0.790.99)
00.61.4
Synonymous OE?0.93
01.21.6
LoF obs/exp: 13 / 16.4Missense obs/exp: 226 / 255.4Syn Z: 0.59

This gene — mechanism propensity

DN
0.86top 5%
GOF
0.79top 25%
LOF
0.1993th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and gain-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median
GOFprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

92 submitted variants in ClinVar

Classification Summary

VUS74
Likely Benign16
74
VUS
16
Likely Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
0
0
0
Likely Pathogenic
0
0
0
0
0
VUS
0
74
0
0
74
Likely Benign
1
15
0
0
16
Benign
0
0
0
0
0
Total1890090

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

39 pathogenic / likely-pathogenic (of 44) ClinVar copy-number / structural variants overlap HTR3D — these span large chromosomal regions, not the gene specifically, and are excluded from the counts above. Explore in CNV tools →

Protein Context — Lollipop Plot

HTR3D · protein map & ClinVar variants

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

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →