rs1026613471

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_000092.5(COL4A4):​c.1223G>A​(p.Gly408Glu) variant causes a missense change. The variant allele was found at a frequency of 0.0000109 in 1,461,464 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 Likely pathogenic (★★).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

COL4A4
NM_000092.5 missense

Scores

11
7
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 4.98
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.99
PP5
Variant 2-227094271-C-T is Pathogenic according to our data. Variant chr2-227094271-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 562349.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
COL4A4NM_000092.5 linkuse as main transcriptc.1223G>A p.Gly408Glu missense_variant 20/48 ENST00000396625.5 NP_000083.3

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
COL4A4ENST00000396625.5 linkuse as main transcriptc.1223G>A p.Gly408Glu missense_variant 20/485 NM_000092.5 ENSP00000379866 P1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD3 exomes
AF:
0.0000241
AC:
6
AN:
248574
Hom.:
0
AF XY:
0.0000296
AC XY:
4
AN XY:
134952
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.000499
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000888
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000109
AC:
16
AN:
1461464
Hom.:
0
Cov.:
31
AF XY:
0.0000124
AC XY:
9
AN XY:
727018
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.000421
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000360
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.000102
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:3
Likely pathogenic, no assertion criteria providedresearchGharavi Laboratory, Columbia UniversitySep 16, 2018- -
Likely pathogenic, criteria provided, single submitterclinical testingAthena DiagnosticsMay 02, 2019The variant disrupts a glycine residue in the canonical Gly-X-Y repeats of the triple helix domain, which are required for stability and structure of this protein. Therefore it is expected to severely affect the function of the protein. The best available variant frequency is uninformative because it is below the disease allele frequency. -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpOct 24, 2023This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 408 of the COL4A4 protein (p.Gly408Glu). This variant is present in population databases (no rsID available, gnomAD 0.05%). This missense change has been observed in individuals with clinical features of Alport syndrome (Invitae). ClinVar contains an entry for this variant (Variation ID: 562349). 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%. For these reasons, this variant has been classified as Pathogenic. -
Autosomal recessive Alport syndrome Pathogenic:2
Likely pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpMar 01, 2024Variant summary: COL4A4 c.1223G>A (p.Gly408Glu) results in a non-conservative amino acid change located in the Collagen triple helix repeat (IPR008160) of the encoded protein sequence. This missense variant disrupts a critical glycine residue at position 1 of a Gly-X-Y repeat in the collagenous domain of the collagen IV alpha 4 chain, and variants affecting these glycine residues are significantly enriched in individuals with Alport syndrome (PMID: 33854215). 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 2.4e-05 in 248574 control chromosomes. c.1223G>A has been reported at a heterozygous state in the literature in at-least one individual affected with Glomerulopathy (Groopman_2019). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 30586318). ClinVar contains an entry for this variant (Variation ID: 562349). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Likely pathogenic, criteria provided, single submitterclinical testingDivision Of Personalized Genomic Medicine, Columbia University Irving Medical CenterNov 11, 2019The c.1223G>A variant in the COL4A4 gene is a missense variant, which results in the substitution of the highly conserved glycine residue at the 408 position to glutamic acid (p.Gly408Glu). This variant localizes to coding exon 20 of the COL4A4 gene (48 exons total; NP_000083.3) and is within the triple helical domain of the protein. To the best of our knowledge, this specific variant has not been described to be associated with disease. However, glycine substitutions within the triple helical domain of this protein are a known mechanism of disease. In silico analysis predicts this change to be deleterious and damaging to the structure and/or function of the protein (probably damaging by PolyPhen2 and damaging by SIFT). This variant has been observed in the Genome Aggregation Database (gnomAD) at a very low frequency (6/248,574), indicating it is not a common benign variant in the populations represented in this database. Of note, allele frequency is higher among individuals of Ashkenazi Jewish descent (5/10,026). Based on the evidence presented, this variant is classified as likely pathogenic. -
Benign familial hematuria;C4746745:Autosomal recessive Alport syndrome Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsApr 05, 2022- -
Alport syndrome Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingVictorian Clinical Genetics Services, Murdoch Childrens Research InstituteSep 20, 2024Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0103 - Loss of function is a known mechanism of disease for this gene and is associated with COL4A4-related nephropathy. Dominant negative is a suspected mechanism of disease for this gene as it is a structural protein (PMIDs: 12028435, 24046192). (I) 0108 - This gene is associated with both recessive and dominant disease. Alport syndrome typically has biallelic inheritance, although rare cases of monoallelic inheritance have been reported (PMID: 28704582). Thin basement membrane nephropathy (TBMN) and focal segmental glomerulosclerosis (FSGS) are associated with autosomal dominant inheritance (OMIM, PMIDs: 16467446, 17942953). (I) 0200 - Variant is predicted to result in a missense amino acid change from glycine to glutamic acid. (I) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD (v2) <0.001 for a dominant condition (6 heterozygotes, 0 homozygotes). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0601 - Variant is located in the well-established functional triple helical region (UniProt) of the collagen domain (DECIPHER). (SP) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been classified as pathogenic or likely pathogenic by multiple clinical laboratories in ClinVar and has been observed in one individual with Alport syndrome 2 in the literature (PMID: 34993602). (SP) 0906 - Segregation evidence for this variant is inconclusive. This variant has segregated in this individuals brother and nephew, however this is insufficient evidence for pathogenicity. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
COL4A4-related disorder Pathogenic:1
Pathogenic, no assertion criteria providedclinical testingPreventionGenetics, part of Exact SciencesAug 02, 2024The COL4A4 c.1223G>A variant is predicted to result in the amino acid substitution p.Gly408Glu. This variant was reported in the heterozygous state in an individual with glomerulopathy and family history of kidney disease (Table S7 of Groopman et al. 2019. PubMed ID: 30586318). At PreventionGenetics, we have observed this variant in the heterozygous state in a patient with microhematuria and proteinuria and in another patient with Alport syndrome who also carried a COL4A4 nonsense variant (internal data). The p.Gly408Glu variant affects a glycine (Gly) residue of the conserved triple helical domain (residues 65 – 1459) of the COL4A4 protein (uniprot.org), where substitutions of the glycine (Gly) residue are usually pathogenic (Hudson et al. 1993. PubMed ID: 8253711; https://www.ncbi.nlm.nih.gov/books/NBK1207/). In addition, at other glycine (Gly) residues within this domain, substitutions of a glycine (Gly) with a glutamic acid (Glu) have been widely reported to be pathogenic for autosomal recessive or dominant COL4A4 nephropathy (see for example, autosomal recessive Alport syndrome, p.Gly152Glu at Supplementary Table 1 of Morinière et al. 2014. PubMed ID: 24854265; autosomal dominant focal segmental glomerulosclerosis, p.Gly602Glu in Isaranuwatchai et al. 2023. PubMed ID: 36646731). The c.1223G>A (p.Gly408Glu) variant is reported in 0.050% of alleles in individuals of Ashkenazi Jewish descent in gnomAD. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.69
BayesDel_addAF
Pathogenic
0.26
D
BayesDel_noAF
Uncertain
0.13
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.66
D
Eigen
Pathogenic
0.91
Eigen_PC
Pathogenic
0.80
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Uncertain
0.96
D
M_CAP
Pathogenic
0.64
D
MetaRNN
Pathogenic
0.99
D
MetaSVM
Pathogenic
0.95
D
MutationAssessor
Pathogenic
3.2
M
MutationTaster
Benign
1.0
D;D
PrimateAI
Uncertain
0.74
T
PROVEAN
Pathogenic
-7.2
D
REVEL
Pathogenic
0.87
Sift
Uncertain
0.0030
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.73
MutPred
0.95
Loss of glycosylation at P407 (P = 0.1988);
MVP
0.88
MPC
0.71
ClinPred
0.92
D
GERP RS
5.3
Varity_R
0.66
gMVP
0.91

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.

Other links and lift over

dbSNP: rs1026613471; hg19: chr2-227958987; API