2-227245971-CG-C

Position:

• chr2-227245971-CG-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000091.5(COL4A3):​c.345delG​(p.Pro116fs) variant causes a frameshift change. The variant allele was found at a frequency of 0.0000143 in 1,613,858 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: COL4A3 NM_000091.5 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: 5.11

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]

MFF-DT (HGNC:):

ACMG classification

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 2-227245971-CG-C is Pathogenic according to our data. Variant chr2-227245971-CG-C is described in ClinVar as [Pathogenic]. Clinvar id is 554004.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
COL4A3	NM_000091.5	c.345delG	p.Pro116fs	frameshift_variant	6/52	ENST00000396578.8	NP_000082.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL4A3	ENST00000396578.8	c.345delG	p.Pro116fs	frameshift_variant	6/52	1	NM_000091.5	ENSP00000379823.3

Frequencies

GnomAD3 genomes AF: 0.0000394 AC: 6 AN: 152186 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000327

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

GnomAD3 exomes AF: 0.0000361 AC: 9 AN: 249432 Hom.: 0 AF XY: 0.0000369 AC XY: 5 AN XY: 135318

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000232

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000165

GnomAD4 exome AF: 0.0000116 AC: 17 AN: 1461554 Hom.: 0 Cov.: 30 AF XY: 0.0000124 AC XY: 9 AN XY: 727098

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000268

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: 0.00000360

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000394 AC: 6 AN: 152304 Hom.: 0 Cov.: 32 AF XY: 0.0000537 AC XY: 4 AN XY: 74478

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000327

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: 0.0000189

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal recessive Alport syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Sep 21, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jun 03, 2020	Variant summary: COL4A3 c.345delG (p.Pro116LeufsX37) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 3.6e-05 in 249432 control chromosomes. c.345delG has been reported in the literature in multiple individuals affected with Alport Syndrome, Autosomal Recessive (e.g. Moriniere_2014) or Autosomal Dominant (e.g. Rosado_2015). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Centogene AG - the Rare Disease Company	-	- -

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 24, 2023	This sequence change creates a premature translational stop signal (p.Pro116Leufs*37) in the COL4A3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in COL4A3 are known to be pathogenic (PMID: 8956999, 24854265, 26809805, 27281700). This variant is present in population databases (rs749390823, gnomAD 0.02%). This premature translational stop signal has been observed in individual(s) with clinical features of COL4A3-related conditions (PMID: 24854265, 26277931). ClinVar contains an entry for this variant (Variation ID: 554004). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Mar 27, 2024	Frameshift 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; Reported in heterozygous state in two patients belonging to a single family with bilateral hearing loss and renal disease; of note, several additional family members were noted only to have hearing loss (PMID: 25450602); This variant is associated with the following publications: (PMID: 33532864, 33353754, 31589614, 33838161, 32860008, 26277931, 29246570, 25450602, 24854265) -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Sep 09, 2022	- -

Alport syndrome Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Natera, Inc.

Sep 16, 2020

- -

Autosomal dominant Alport syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

research

Molecular Biology Laboratory, Fundació Puigvert

Feb 01, 2020

- -

Computational scores

Source: dbNSFP v4.3

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

Other links and lift over

dbSNP: rs749390823; hg19: chr2-228110687;