chr3-4814509-G-A

Variant names:

• chr3-4814509-G-A
• rs1553757628
• NM_001378452.1:c.7648G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_001378452.1(ITPR1):​c.7648G>A​(p.Gly2550Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 14/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar.

• Frequency:
  • Genomes: not found (cov: 29)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: ITPR1 NM_001378452.1 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:4
• Conservation: PhyloP100: 9.52
• Publications: 0 publications found

Genes affected

ITPR1 (HGNC:6180): (inositol 1,4,5-trisphosphate receptor type 1) 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]

ITPR1 Gene-Disease associations (from GenCC):

• aniridia-cerebellar ataxia-intellectual disability syndrome

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, G2P, Genomics England PanelApp, PanelApp Australia, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
• spinocerebellar ataxia type 29

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen, Orphanet
• spinocerebellar ataxia type 15/16

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)

ENSG00000235978 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_001378452.1
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.93

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001378452.1. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ITPR1	NM_001378452.1	MANE Select	c.7648G>A	p.Gly2550Arg	missense	Exon 58 of 62	NP_001365381.1
	ITPR1	NM_001168272.2		c.7603G>A	p.Gly2535Arg	missense	Exon 57 of 61	NP_001161744.1
	ITPR1	NM_001099952.4		c.7504G>A	p.Gly2502Arg	missense	Exon 55 of 59	NP_001093422.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ITPR1	ENST00000649015.2	MANE Select	c.7648G>A	p.Gly2550Arg	missense	Exon 58 of 62	ENSP00000497605.1
	ITPR1	ENST00000354582.12	TSL:5	c.7624G>A	p.Gly2542Arg	missense	Exon 58 of 62	ENSP00000346595.8
	ITPR1	ENST00000648266.1		c.7621G>A	p.Gly2541Arg	missense	Exon 58 of 62	ENSP00000498014.1

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1461626 Hom.: 0 Cov.: 38 AF XY: 0.00 AC XY: 0 AN XY: 727082

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53396

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5754

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111814

Other (OTH) AF: 0.00 AC: 0 AN: 60370

GnomAD4 genome Cov.: 29

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:4

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:2

Jan 04, 2024

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 34758253)

Sep 11, 2019

Athena Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Apr 12, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt ITPR1 protein function. ClinVar contains an entry for this variant (Variation ID: 520945). This variant has not been reported in the literature in individuals affected with ITPR1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 2487 of the ITPR1 protein (p.Gly2487Arg).

Spinocerebellar ataxia type 29 Pathogenic:1

Genomics England Pilot Project, Genomics England

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

Gillespie syndrome;C1847725:Spinocerebellar ataxia type 15/16;C1861732:Spinocerebellar ataxia type 29 Uncertain:1

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Inborn genetic diseases Uncertain:1

Mar 15, 2016

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.97	D
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.90
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.93	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.6	H
PhyloP100		9.5
PrimateAI	Pathogenic	0.89	D
PROVEAN	Pathogenic	-7.8	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.72		Gain of MoRF binding (P = 0.0508)
MVP		0.99
MPC		2.2
ClinPred		1.0	D
GERP RS		4.9
PromoterAI		0.025	Neutral
Varity_R		0.93
gMVP		1.0
Mutation Taster		=6/94	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1553757628; hg19: chr3-4856193;