rs926605269

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000092.5(COL4A4):​c.1405G>T​(p.Gly469*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000124 in 1,613,470 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: 𝑓 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

COL4A4
NM_000092.5 stop_gained

Scores

4
2
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 4.18

Publications

1 publications found
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 Gene-Disease associations (from GenCC):
  • autosomal recessive Alport syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P, Orphanet, Ambry Genetics, Myriad Women’s Health
  • Alport syndrome
    Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
  • hematuria, benign familial, 1
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
  • autosomal dominant Alport syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 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 2-227089922-C-A is Pathogenic according to our data. Variant chr2-227089922-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 553870.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL4A4NM_000092.5 linkc.1405G>T p.Gly469* stop_gained Exon 21 of 48 ENST00000396625.5 NP_000083.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL4A4ENST00000396625.5 linkc.1405G>T p.Gly469* stop_gained Exon 21 of 48 5 NM_000092.5 ENSP00000379866.3

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151924
Hom.:
0
Cov.:
31
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461546
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
727102
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33472
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86246
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53392
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111744
Other (OTH)
AF:
0.00
AC:
0
AN:
60388
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.325
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
151924
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
74168
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41388
American (AMR)
AF:
0.00
AC:
0
AN:
15236
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5166
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4808
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10542
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67998
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000329
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive Alport syndrome Pathogenic:1
Sep 16, 2017
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

not provided Pathogenic:1
May 09, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 553870). This premature translational stop signal has been observed in individual(s) with clinical features of Alport syndrome (PMID: 15954103). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gly469*) 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). For these reasons, this variant has been classified as Pathogenic. -

Autosomal dominant Alport syndrome Pathogenic:1
Mar 30, 2023
Molecular Genetics, Royal Melbourne Hospital
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change in COL4A4 is a nonsense variant predicted to cause a premature stop codon (p.(Gly469*)) in biologically-relevant-exon 21/48 leading to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PMID: 20301386). This variant is present in a single European (non-Finnish) individual in gnomAD v2.1 (1/67,998 alleles). This variant has been reported in at least two probands with a phenotype consistent with autosomal dominant Alport syndrome (PMID: 15954103; Royal Melbourne Hospital). Based on the classification scheme RMH Modified ACMG Guidelines v1.4.0, this variant is classified as PATHOGENIC. Following criteria are met: PVS1, PS4_Supporting, PM2_Supporting. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.63
CADD
Pathogenic
40
DANN
Uncertain
0.99
Eigen
Pathogenic
0.94
Eigen_PC
Pathogenic
0.75
FATHMM_MKL
Uncertain
0.95
D
PhyloP100
4.2
Vest4
0.75
GERP RS
6.0
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.25
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.25
Position offset: 35

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

Publications

Other links and lift over

dbSNP: rs926605269; hg19: chr2-227954638; API