rs144437882

Positions:

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 4P and 4B. PM2PM5BP4_Strong

The NM_001563.4(IMPG1):c.1157C>T(p.Ala386Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,612,622 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A386D) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

IMPG1
NM_001563.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.975

Variant links:

Genes affected

IMPG1 (HGNC:6055): (interphotoreceptor matrix proteoglycan 1) This gene encodes a protein that is a major component of the retinal interphotoreceptor matrix. The encoded protein is a proteoglycan that is thought to play a role in maintaining viability of photoreceptor cells and in adhesion of the neural retina to the retinal pigment epithelium. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Sep 2013]

IMPG1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr6-76003929-G-T is described in Lovd as [Likely_pathogenic].

BP4

Computational evidence support a benign effect (MetaRNN=0.04278329).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
IMPG1	NM_001563.4 linkuse as main transcript	c.1157C>T	p.Ala386Val	missense_variant	11/17	ENST00000369950.8	NP_001554.2
IMPG1	NM_001282368.2 linkuse as main transcript	c.923C>T	p.Ala308Val	missense_variant	10/16		NP_001269297.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IMPG1	ENST00000369950.8 linkuse as main transcript	c.1157C>T	p.Ala386Val	missense_variant	11/17	1	NM_001563.4	ENSP00000358966	P2	Q17R60-1
IMPG1	ENST00000611179.4 linkuse as main transcript	c.923C>T	p.Ala308Val	missense_variant	10/16	5		ENSP00000481913	A2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152156

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:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000400

AC:

AN:

249952

Hom.:

AF XY:

0.00000740

AC XY:

AN XY:

135134

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:

0.00000883

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1460466

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726560

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:

0.00

Gnomad4 NFE exome

AF:

9.00e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152156

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74328

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:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 14, 2023

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. This variant has not been reported in the literature in individuals affected with IMPG1-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 386 of the IMPG1 protein (p.Ala386Val). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.076

BayesDel_addAF

Benign

-0.35

BayesDel_noAF

Benign

-0.75

CADD

Benign

0.15

DANN

Benign

0.63

DEOGEN2

Benign

0.0032

T;.

Eigen

Benign

-1.7

Eigen_PC

Benign

-1.8

FATHMM_MKL

Benign

0.0039

LIST_S2

Benign

0.59

T;T

M_CAP

Benign

0.0015

MetaRNN

Benign

0.043

T;T

MetaSVM

Benign

-0.97

MutationAssessor

Benign

-1.0

N;.

MutationTaster

Benign

1.0

N;N

PrimateAI

Benign

0.21

PROVEAN

Benign

-0.45

N;.

REVEL

Benign

0.020

Sift

Benign

0.66

T;.

Sift4G

Benign

0.34

T;T

Polyphen

0.0

B;.

Vest4

0.055

MutPred

0.24

Loss of disorder (P = 0.0565);.;

MVP

0.072

MPC

0.013

ClinPred

0.025

GERP RS

-5.8

Varity_R

0.025

gMVP

0.092

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