2-227310813-T-G

Position:

chr2-227310813-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1PM2PP3_ModeratePP5

The NM_000091.5(COL4A3):c.4793T>G(p.Leu1598Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000223 in 1,614,168 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 0.000033 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

COL4A3
NM_000091.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:2

Conservation

PhyloP100: 7.67

Variant links:

Genes affected

COL4A3 (HGNC:2204): (collagen type IV alpha 3 chain) Type IV collagen, the major structural component of basement membranes, is a multimeric protein composed of 3 alpha subunits. These subunits are encoded by 6 different genes, alpha 1 through alpha 6, each of which can form a triple helix structure with 2 other subunits to form type IV collagen. This gene encodes alpha 3. In the Goodpasture syndrome, autoantibodies bind to the collagen molecules in the basement membranes of alveoli and glomeruli. The epitopes that elicit these autoantibodies are localized largely to the non-collagenous C-terminal domain of the protein. A specific kinase phosphorylates amino acids in this same C-terminal region and the expression of this kinase is upregulated during pathogenesis. This gene is also linked to an autosomal recessive form of Alport syndrome. The mutations contributing to this syndrome are also located within the exons that encode this C-terminal region. Like the other members of the type IV collagen gene family, this gene is organized in a head-to-head conformation with another type IV collagen gene so that each gene pair shares a common promoter. [provided by RefSeq, Jun 2010]

COL4A3 links:

MFF-DT (HGNC:41067): (MFF divergent transcript)

MFF-DT links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PM1

In a disulfide_bond Or C-1570 with C-1662 (size 95) in uniprot entity CO4A3_HUMAN there are 21 pathogenic changes around while only 1 benign (95%) in NM_000091.5

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.921

PP5

Variant 2-227310813-T-G is Pathogenic according to our data. Variant chr2-227310813-T-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 550745.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Likely_pathogenic=2, Uncertain_significance=2}. Variant chr2-227310813-T-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
COL4A3	NM_000091.5 linkuse as main transcript	c.4793T>G	p.Leu1598Arg	missense_variant	51/52	ENST00000396578.8
MFF-DT	NR_102371.1 linkuse as main transcript	n.48-5158A>C		intron_variant, non_coding_transcript_variant
COL4A3	XM_005246277.4 linkuse as main transcript	c.4688T>G	p.Leu1563Arg	missense_variant	50/51
COL4A3	XM_011510555.2 linkuse as main transcript	c.4780T>G	p.Trp1594Gly	missense_variant	51/51

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL4A3	ENST00000396578.8 linkuse as main transcript	c.4793T>G	p.Leu1598Arg	missense_variant	51/52	1	NM_000091.5	P1	Q01955-1
MFF-DT	ENST00000439598.6 linkuse as main transcript	n.48-5158A>C		intron_variant, non_coding_transcript_variant		1

Frequencies

GnomAD3 genomes

AF:

0.0000328

AC:

AN:

152224

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:

0.000962

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000561

AC:

AN:

249436

Hom.:

AF XY:

0.0000443

AC XY:

AN XY:

135344

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000779

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000212

AC:

AN:

1461826

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

727218

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000731

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

8.99e-7

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152342

Hom.:

Cov.:

AF XY:

0.0000268

AC XY:

AN XY:

74514

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000965

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000416

ExAC

AF:

0.0000331

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Autosomal recessive Alport syndrome

Pathogenic:2Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jul 01, 2019	Variant summary: COL4A3 c.4793T>G (p.Leu1598Arg) results in a non-conservative amino acid change located in the Collagen IV, non-collagenous domain (IPR001442) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 5.6e-05 in 249436 control chromosomes (gnomAD). This frequency is not significantly higher than expected for a pathogenic variant in COL4A3 causing Alport Syndrome, autosomal recessive (5.6e-05 vs 0.002), allowing no conclusion about variant significance. c.4793T>G has been reported in the literature in at-least 5 individuals affected with autosomal recessive Alport Syndrome in compound heterozygosity (Oka_2014). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One other submitter has provided clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation and classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Feb 14, 2017	- -
Uncertain significance, criteria provided, single submitter	research	Precision Medicine Center, Zhengzhou University	-	PM1:Located in a mutational hot spot PM2:not found in gnomAD PP3:Multiple lines of computational evidence support a deleterious effect on the gene or gene product -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 17, 2024

This sequence change replaces leucine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 1598 of the COL4A3 protein (p.Leu1598Arg). This variant is present in population databases (rs752452590, gnomAD 0.08%). This missense change has been observed in individual(s) with COL4A3-related conditions (PMID: 24633401). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 550745). 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 COL4A3 protein function with a positive predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -

Autosomal dominant Alport syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

May 15, 2018

A heterozygous missense variant, NM_000091.4(COL4A3):c.4793T>G, has been identified in exon 51 of 52 of the COL4A3 gene. The variant is predicted to result in a major amino acid change from leucine to arginine at position 1598 of the protein (NP_000082.2(COL4A3):p.(Leu1598Arg)). The leucine residue at this position has very high conservation (100 vertebrates, UCSC), and is located within the C4 domain. In silico predictions for this variant are consistently pathogenic (Polyphen, SIFT, CADD, Mutation Taster). The variant is present in the gnomAD database at a frequency of 0.005% (0 homozygotes). This variant has not been previously reported in clinical cases. Based on the information available at the time of curation, this variant has been classified as VARIANT of UNCERTAIN SIGNIFICANCE (VUS). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.93

BayesDel_addAF

Pathogenic

0.30

BayesDel_noAF

Pathogenic

0.58

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.65

Eigen

Pathogenic

0.96

Eigen_PC

Pathogenic

0.87

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.70

MetaRNN

Pathogenic

0.92

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.8

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.72

PROVEAN

Pathogenic

-5.7

REVEL

Pathogenic

0.98

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0010

Polyphen

1.0

Vest4

0.99

MutPred

0.72

Loss of sheet (P = 0.0054);

MVP

0.97

MPC

0.28

ClinPred

0.76

GERP RS

5.9

Varity_R

0.97

gMVP

0.98

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