rs201893545

Positions:

chr3-101304277-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PP3_ModeratePP5

The NM_016247.4(IMPG2):c.370T>C(p.Phe124Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000626 in 1,613,764 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000064 ( 0 hom. )

Consequence

IMPG2
NM_016247.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:1

Conservation

PhyloP100: 8.82

Variant links:

Genes affected

IMPG2 (HGNC:18362): (interphotoreceptor matrix proteoglycan 2) The protein encoded by this gene binds chondroitin sulfate and hyaluronan and is a proteoglycan. The encoded protein plays a role in the organization of the interphotoreceptor matrix and may promote the growth and maintenance of the light-sensitive photoreceptor outer segment. Defects in this gene are a cause of retinitis pigmentosa type 56 and maculopathy, IMPG2-related.[provided by RefSeq, Mar 2011]

IMPG2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.848

PP5

Variant 3-101304277-A-G is Pathogenic according to our data. Variant chr3-101304277-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 3550.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1, Likely_pathogenic=1}. Variant chr3-101304277-A-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
IMPG2	NM_016247.4 linkuse as main transcript	c.370T>C	p.Phe124Leu	missense_variant	3/19	ENST00000193391.8	NP_057331.2	Q9BZV3F1T0J3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IMPG2	ENST00000193391.8 linkuse as main transcript	c.370T>C	p.Phe124Leu	missense_variant	3/19	1	NM_016247.4	ENSP00000193391.6		Q9BZV3

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152136

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.0000943

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000882

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000637

AC:

AN:

251240

Hom.:

AF XY:

0.0000589

AC XY:

AN XY:

135786

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000132

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000643

AC:

AN:

1461628

Hom.:

Cov.:

AF XY:

0.0000591

AC XY:

AN XY:

727122

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000562

Gnomad4 NFE exome

AF:

0.0000783

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152136

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74314

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.0000943

Gnomad4 NFE

AF:

0.0000882

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000139

Hom.:

Bravo

AF:

0.0000416

ExAC

AF:

0.0000824

AC:

EpiCase

AF:

0.000327

EpiControl

AF:

0.000415

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 09, 2024

This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 124 of the IMPG2 protein (p.Phe124Leu). This variant is present in population databases (rs201893545, gnomAD 0.01%). This missense change has been observed in individual(s) with rod-cone dystrophy or autosomal recessive maculopathy (PMID: 20673862; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 3550). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. For these reasons, this variant has been classified as Pathogenic. -

Vitelliform macular dystrophy 5

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Dec 01, 2014

- -

Retinal dystrophy

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Jan 01, 2018

- -

Retinitis pigmentosa

Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

Sharon lab, Hadassah-Hebrew University Medical Center

Jun 23, 2019

- -

Retinitis pigmentosa 56

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

May 21, 2020

A heterozygous missense variant was identified, NM_016247.3(IMPG2):c.370T>C in exon 3 of the IMPG2 gene. This substitution is predicted to create a minor amino acid change from a phenylalanine to a leucine at position 124 of the protein; NP_057331.2(IMPG2):p.(Phe124Leu). The phenylalanine at this position has very high conservation (100 vertebrates, UCSC), and is not situated in a known functional domain (NCBI, PDB). In silico software predictions of the pathogenicity of this variant are conflicting (PolyPhen2, FATHMM, MutationAssessor, PROVEAN). The variant is present in the gnomAD population database at a global population frequency of 0.007% (19 heterozygotes, 0 homozygotes) with a European sub-population frequency of 0.01%. This variant has been previously reported as pathogenic (ClinVar; Bandah-Rozenfeld, D. et al. (2010)). Based on information available at the time of curation, this variant has been classified as a VUS with POTENTIAL CLINICAL RELEVANCE. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.23

BayesDel_noAF

Pathogenic

0.35

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.53

Eigen

Pathogenic

0.88

Eigen_PC

Pathogenic

0.85

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.90

M_CAP

Uncertain

0.11

MetaRNN

Pathogenic

0.85

MetaSVM

Uncertain

0.42

MutationAssessor

Pathogenic

3.2

PrimateAI

Uncertain

0.73

PROVEAN

Pathogenic

-4.9

REVEL

Pathogenic

0.91

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.94

MutPred

0.58

Gain of MoRF binding (P = 0.1145);

MVP

0.72

MPC

0.45

ClinPred

0.90

GERP RS

5.8

Varity_R

0.85

gMVP

0.73

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over