dbSNP rs121912861: COL4A4:p.Arg1377* (chr2-227022135-G-A) – ACMG Classification: Pathogenic (18 pts)

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000092.5(COL4A4):c.4129C>T(p.Arg1377*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000821 in 1,461,862 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

COL4A4
NM_000092.5 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:14

Conservation

PhyloP100: 0.211

Variant links:

Genes affected

COL4A4 (HGNC:2206): (collagen type IV alpha 4 chain) This gene encodes one of the six subunits of type IV collagen, the major structural component of basement membranes. This particular collagen IV subunit, however, is only found in a subset of basement membranes. 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. Mutations in this gene are associated with type II autosomal recessive Alport syndrome (hereditary glomerulonephropathy) and with familial benign hematuria (thin basement membrane disease). Two transcripts, differing only in their transcription start sites, have been identified for this gene and, as is common for collagen genes, multiple polyadenylation sites are found in the 3' UTR. [provided by RefSeq, Jul 2008]

COL4A4 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 2-227022135-G-A is Pathogenic according to our data. Variant chr2-227022135-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 17407.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-227022135-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL4A4	NM_000092.5 link	c.4129C>T	p.Arg1377*	stop_gained	Exon 44 of 48	ENST00000396625.5	NP_000083.3	P53420

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL4A4	ENST00000396625.5 link	c.4129C>T	p.Arg1377*	stop_gained	Exon 44 of 48	5	NM_000092.5	ENSP00000379866.3		P53420

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000803

AC:

AN:

248918

Hom.:

AF XY:

0.00000740

AC XY:

AN XY:

135104

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.0000994

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000887

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000821

AC:

AN:

1461862

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

727228

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000809

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000324

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:14

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:4

Nov 21, 2024

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is expected to result in the loss of a functional protein. The frequency of this variant in the general population is consistent with pathogenicity. (http://gnomad.broadinstitute.org) This variant has been identified in at least one individual with clinical features associated with this gene. -

Sep 16, 2018

Gharavi Laboratory, Columbia University

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Oct 22, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Identified in a patient with thin basement membrane disease in published literature; variant reported to segregate with additional family members with hematuria but data is limited (PMID: 12631110); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 37097554, 25525159, 31589614, 33712733, 31576025, 30586318, 32939031, 29854973, 38978054, 9792860, 12631110) -

Jun 03, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg1377*) in the COL4A4 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in COL4A4 are known to be pathogenic (PMID: 21196518, 24854265, 25307543). This variant is present in population databases (rs121912861, gnomAD 0.01%). This premature translational stop signal has been observed in individual(s) with autosomal recessive Alport syndrome and/or thin basement membrane disease with hematuria (PMID: 9792860, 12631110). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 17407). For these reasons, this variant has been classified as Pathogenic. -

Autosomal recessive Alport syndrome

Pathogenic:3

Nov 01, 1998

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Nov 16, 2021

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

NM_000092.4(COL4A4):c.4129C>T(R1377*) is a nonsense variant classified as pathogenic in the context of COL4A4-related Alport syndrome. R1377* has been observed in cases with relevant disease (PMID: 9792860). Functional assessments of this variant are not available in the literature. R1377* has been observed in population frequency databases (gnomAD: ASJ 0.01%). In summary, NM_000092.4(COL4A4):c.4129C>T(R1377*) is a nonsense variant in a gene where loss of function is a known mechanism of disease and is predicted to disrupt protein function. Please note: this variant was assessed in the context of healthy population screening. -

Sep 20, 2023

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.001%). Predicted Consequence/Location: Stop-gained (nonsense): predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000017407 /PMID: 9792860). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

Alport syndrome

Pathogenic:2

Oct 24, 2018

Sydney Genome Diagnostics, Children's Hospital Westmead

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

This patient is heterozygous for a known pathogenic variant, c.4139C>T p.(Arg1377*), in the COL4A4 gene. This variant (dbSNP: rs121912861) creates a premature stop codon p.(Arg1377*), and may result in a null allele due to nonsense-mediated mRNA decay. This variant is considered to be pathogenic, and has been previously reported in conjunction with a second pathogenic mutation in two patients with Alport syndrome in the literature (Boye et al 1998 Am. J. Hum. Genet. 63:1329-40). -

Feb 22, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Autosomal recessive Alport syndrome;CN376803:Hematuria, benign familial, 1

Pathogenic:1

Jan 15, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Kidney damage

Pathogenic:1

Equipe Genetique des Anomalies du Developpement, Université de Bourgogne

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Benign familial hematuria

Pathogenic:1

Jun 28, 2018

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

A heterozygous nonsense variant, NM_000092.4(COL4A4):c.4129C>T, has been identified in exon 44 of 48 of the COL4A4 gene. The variant is predicted to result in a premature stop codon at position 1377 of the protein, NP_000083.3(COL4A4):p.(Arg1377*). This variant is predicted to result in loss of protein function either through truncation (including loss of a quarter of the protein) or nonsense-mediated decay, which is a reported mechanism of pathogenicity for this gene. The variant is present in the gnomAD database at a frequency of 0.00081% (2 heterozygotes, 0 homozygote). The variant has previously been described as pathogenic in multiple patients with Alport syndrome (ClinVar, Boye, E., et al. (1998), Buzza, M., et al. (2001), Buzza, M., et al. (2003)) and has also been shown to segregate with haematuria in these families. In addition, other truncating variants upstream and downstream of this variant have been reported as pathogenic in individuals with Alport sydrome. Based on the information available at the time of curation, this variant has been classified as PATHOGENIC. -

Autosomal dominant Alport syndrome

Pathogenic:1

Jan 03, 2019

Bioscientia Institut fuer Medizinische Diagnostik GmbH, Sonic Healthcare

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

COL4A4-related disorder

Pathogenic:1

Dec 20, 2022

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The COL4A4 c.4129C>T variant is predicted to result in premature protein termination (p.Arg1377*). This variant has been reported in the compound heterozygous or homozygous state in individuals with autosomal recessive Alport syndrome (Family AR18 in Boye et al 1998. PubMed ID: 9792860; Jayasinghe K et al 2020. PubMed ID: 32939031; Gillion V et al. 2018. PubMed ID: 29854973). This variant in the heterozygous state or compound heterozygous state has also been reported in individuals with hematuria (Buzza et al. 2003. PubMed ID: 12631110; Schrezenmeier et al. 2021. PubMed ID: 33712733; Zhang et al. 2020. PubMed ID: 31576025). This variant is reported in 0.0099% of alleles in individuals of Ashkenazi Jewish descent in gnomAD (http://gnomad.broadinstitute.org/variant/2-227886851-G-A). Nonsense variants in COL4A4 are expected to be pathogenic. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.56

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.46

Eigen_PC

Uncertain

0.25

FATHMM_MKL

Benign

0.19

Vest4

0.85

GERP RS

2.2

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

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