2-227051141-C-T

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM5PP3_StrongPP5

The NM_000092.5(COL4A4):​c.2986G>A​(p.Gly996Arg) variant causes a missense change. The variant allele was found at a frequency of 0.0000403 in 1,614,004 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). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G996W) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000040 ( 0 hom. )

Consequence

COL4A4
NM_000092.5 missense

Scores

13
4
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:3

Conservation

PhyloP100: 5.80

Publications

3 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: Likely_pathogenic. The variant received 7 ACMG points.

PM5
Other missense variant is known to change same aminoacid residue: Variant chr2-227051141-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 2916276.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.993
PP5
Variant 2-227051141-C-T is Pathogenic according to our data. Variant chr2-227051141-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 222055.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL4A4NM_000092.5 linkc.2986G>A p.Gly996Arg missense_variant Exon 33 of 48 ENST00000396625.5 NP_000083.3 P53420

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL4A4ENST00000396625.5 linkc.2986G>A p.Gly996Arg missense_variant Exon 33 of 48 5 NM_000092.5 ENSP00000379866.3 P53420

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152150
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000735
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000281
AC:
7
AN:
249466
AF XY:
0.0000222
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000530
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000404
AC:
59
AN:
1461854
Hom.:
0
Cov.:
34
AF XY:
0.0000385
AC XY:
28
AN XY:
727226
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000477
AC:
53
AN:
1111974
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.467
Heterozygous variant carriers
0
4
7
11
14
18
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000394
AC:
6
AN:
152150
Hom.:
0
Cov.:
32
AF XY:
0.0000538
AC XY:
4
AN XY:
74322
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41426
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000735
AC:
5
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.533
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000540
Hom.:
0
Bravo
AF:
0.0000264
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000122
AC:
1
ExAC
AF:
0.0000331
AC:
4
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:4Uncertain:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Benign familial hematuria Pathogenic:2
Feb 02, 2016
Genetic Diagnostic Laboratory, University of Szeged
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 18, 2022
Eurofins-Biomnis
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:2
Jan 29, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 996 of the COL4A4 protein (p.Gly996Arg). This variant is present in population databases (rs370474706, gnomAD 0.008%). This missense change has been observed in individual(s) with hematuria and/or proteinuria (PMID: 26934356, 32647767). ClinVar contains an entry for this variant (Variation ID: 222055). 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 COL4A4 protein function with a positive predictive value of 95%. 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. -

Jul 16, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Reported in an individual with hematuria in published literature, however, renal and hearing loss evaluations were not performed on this child (PMID: 26934356); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Affects a glycine residue in a Gly-X-Y motif in the triple helical region of the COL4A4 gene; This variant is associated with the following publications: (PMID: 32647767, 34426522, 26934356) -

Autosomal recessive Alport syndrome;CN376803:Hematuria, benign familial, 1 Pathogenic:1
Jun 18, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

COL4A4-related disorder Pathogenic:1
Jun 25, 2024
PreventionGenetics, part of Exact Sciences
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

The COL4A4 c.2986G>A variant is predicted to result in the amino acid substitution p.Gly996Arg. This variant has been reported in at least two patients with Alport syndrome and IgA related neuropathy (Kovács et al. 2016. PubMed ID: 26934356; Li et al. 2020. PubMed ID: 2647767). This variant is reported in 0.0070% of alleles in individuals of European (Non-Finnish) descent in gnomAD. The p.Gly996Arg variant affects a Gly residue of the conserved triple helical domain (residues 65 – 1459) of the COL4A4 protein (uniprot.org). The majority of pathogenic variants in COL4A4 substitute a glycine residue to a bulkier amino acid in the triple-helical domain (Hudson et al. 1993. PubMed ID: 8253711; https://www.ncbi.nlm.nih.gov/books/NBK1207/). This variant is interpreted as pathogenic. -

Alport syndrome Uncertain:1
Feb 27, 2020
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.71
BayesDel_addAF
Pathogenic
0.42
D
BayesDel_noAF
Pathogenic
0.55
CADD
Benign
23
DANN
Benign
0.96
DEOGEN2
Uncertain
0.66
D
Eigen
Pathogenic
0.76
Eigen_PC
Uncertain
0.55
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.92
D
M_CAP
Pathogenic
0.70
D
MetaRNN
Pathogenic
0.99
D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
4.1
H
PhyloP100
5.8
PrimateAI
Uncertain
0.71
T
PROVEAN
Pathogenic
-7.6
D
REVEL
Pathogenic
0.96
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.96
MutPred
0.95
Gain of MoRF binding (P = 0.0045);
MVP
0.93
MPC
0.17
ClinPred
0.99
D
GERP RS
5.5
Varity_R
0.88
gMVP
0.90
Mutation Taster
=4/96
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs370474706; hg19: chr2-227915857; COSMIC: COSV100307116; API