rs1175052474

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PM4_SupportingPP5

The NM_000091.5(COL4A3):c.3546_3548dup(p.Gly1183_Asn1183insGly) variant causes a inframe insertion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,614,038 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

COL4A3
NM_000091.5 inframe_insertion

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:9U:2

Conservation

PhyloP100: -0.388

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 Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM4

Nonframeshift variant in NON repetitive region in NM_000091.5. Strenght limited to Supporting due to length of the change: 1aa.

PP5

Variant 2-227295295-A-AGAG is Pathogenic according to our data. Variant chr2-227295295-A-AGAG is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 438655.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=5, Pathogenic=2, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL4A3	NM_000091.5 linkuse as main transcript	c.3546_3548dup	p.Gly1183_Asn1183insGly	inframe_insertion	41/52	ENST00000396578.8
MFF-DT	NR_102371.1 linkuse as main transcript	n.243+10164_243+10165insCTC		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL4A3	ENST00000396578.8 linkuse as main transcript	c.3546_3548dup	p.Gly1183_Asn1183insGly	inframe_insertion	41/52	1	NM_000091.5	P1	Q01955-1
MFF-DT	ENST00000439598.6 linkuse as main transcript	n.243+10164_243+10165insCTC		intron_variant, non_coding_transcript_variant		1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152200

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:

0.00

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:

0.00000205

AC:

AN:

1461838

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727222

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152200

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74364

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:9Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:3Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Oct 26, 2021	Not observed in large population cohorts (Lek et al., 2016); In-frame insertion of 1 amino acid in a non-repeat region; Has not been previously published as pathogenic or benign to our knowledge -
Likely pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 08, 2024	This variant, c.3546_3548dup, results in the insertion of 1 amino acid(s) of the COL4A3 protein (p.Gly1183dup), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individuals with Alport syndrome (PMID: 30586318; Invitae). ClinVar contains an entry for this variant (Variation ID: 438655). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Likely pathogenic, no assertion criteria provided	research	Gharavi Laboratory, Columbia University	Sep 16, 2018	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Mar 01, 2024	COL4A3: PM1, PM2, PM4:Supporting, PS4:Supporting -

Autosomal dominant Alport syndrome

Pathogenic:3

Pathogenic, no assertion criteria provided	clinical testing	Bioscientia Institut fuer Medizinische Diagnostik GmbH, Sonic Healthcare	Oct 31, 2019	- -
Pathogenic, criteria provided, single submitter	clinical testing	Centre for Mendelian Genomics, University Medical Centre Ljubljana	Oct 11, 2019	This variant was classified as: Pathogenic. The following ACMG criteria were applied in classifying this variant: PS1,PM1,PM2,PM4. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Institute of Human Genetics Munich, Klinikum Rechts Der Isar, TU München	Jul 28, 2022	- -

COL4A3-related disorder

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Feb 14, 2024

The COL4A3 c.3546_3548dupAGG variant is predicted to result in an in-frame duplication (p.Gly1183dup). This variant has been reported in the heterozygous state in an individual with glomerulopathy (Table S7, Groopman et al. 2019. PubMed ID: 30586318). In addition, at PreventionGenetics, we have previously found this variant in the heterozygous state in an individual tested for the nephrotic syndrome and focal segmental glomerulosclerosis (FSGS) panel. This one amino acid duplication variant occurs at the conserved triple helical domain (residues 43-1438) of the COL4A3 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/). The consequence of this glycine duplication variant is expected to disturb the conserved triple helical Gly-X-Y repeats; and the same type of one amino acid duplication/insertion variant at a different but nearby location has been reported in an individual with isolated hematuria (c.3547_3548insGGA resulting in p.Gly1183_Asn1184insArg at Slajpah et al. 2007. PubMed ID: 17396119). The p.Gly1183dup variant is interpreted as likely pathogenic. -

Proteinuria;C0239937:Microscopic hematuria;C1654921:Moderate albuminuria

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Jan 01, 2017

- -

Macroscopic hematuria

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Jan 01, 2017

- -

Alport syndrome

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

Mar 03, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

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