ITPR1

Chr 3

inositol 1,4,5-trisphosphate receptor type 1

Also known as: ACV, CLA4, INSP3R1, IP3R, IP3R1, PPP1R94, SCA15, SCA16

NCBI Gene: 3708ENSG00000150995UniProt: Q14643

This gene encodes an intracellular receptor for inositol 1,4,5-trisphosphate. Upon stimulation by inositol 1,4,5-trisphosphate, this receptor mediates calcium release from the endoplasmic reticulum. Mutations in this gene cause spinocerebellar ataxia type 15, a disease associated with an heterogeneous group of cerebellar disorders. Multiple transcript variants have been identified for this gene. [provided by RefSeq, Nov 2009]

GeneReviewsResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

UniProtSpinocerebellar ataxia 15
UniProtSpinocerebellar ataxia 29
UniProtGillespie syndrome

Clinical highlights

Gene-disease validity (ClinGen)
aniridia-cerebellar ataxia-intellectual disability syndrome · ADDefinitivesufficient evidence for diagnostic panels3 gene-disease associations curated in total
Interpreting a novel variant
Loss of function is the curated mechanism (Gene2Phenotype) and the gene is intolerant of it in the population — truncating, frameshift and canonical splice variants carry more prior weight here than missense.Curated gene-level mechanism — a prior for triage, not a per-variant call.
1
Active trials
72
Pubs (1 yr)
—
P/LP submissions
—
P/LP missense
0.13
LOEUF· LoF intol.
Multiple*
Mechanism· G2P
📖
GeneReview available — ITPR1
Authoritative clinical overview · Recommended first read
Open GeneReview ↗
Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
Dual constrained — LoF & missense intolerant
LoF Constraint?
0.13LOEUF
pLI 1.000
Z-score 9.93
OE 0.08 (0.05–0.13)
Highly constrained

Among the most LoF-intolerant genes (~top 3%)

Missense Constraint?
5.60Z-score
OE missense 0.59 (0.56–0.63)
895 obs / 1506.0 exp
Constrained

Extremely missense-constrained (top ~0.01%)

Observed / Expected Ratios?
LoF OE?0.08 (0.05–0.13)
0≤0.351.4
Missense OE?0.59 (0.56–0.63)
0≤0.61.4
Synonymous OE?1.09
0≤1.21.6
LoF obs/exp: 11 / 136.0Missense obs/exp: 895 / 1506.0Syn Z: -1.71

ClinVar Variant Classifications

0 submitted variants in ClinVar

ClinVar

Protein Context — Lollipop Plot

ITPR1 · 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