rs766306957

Variant names:

• chr2-227284229-GAGTAAAGGGCC-G
• rs766306957
• NM_000091.5:c.2768_2778delTAAAGGGCCAG

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1 PP5_Very_Strong

The NM_000091.5(COL4A3):​c.2768_2778delTAAAGGGCCAG​(p.Val923GlufsTer13) variant causes a frameshift change. The variant allele was found at a frequency of 0.0000756 in 1,613,968 control chromosomes in the GnomAD database, with no homozygous occurrence. It is difficult to determine the true allele frequency of this variant because it is of type DEL_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000081 (0 hom.)
• Consequence: COL4A3 NM_000091.5 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: 6.09
• Publications: 1 publications found

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:41067): (MFF divergent transcript)

ACMG classification

Our verdict: Pathogenic. The variant received 16 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PP5: Variant 2-227284229-GAGTAAAGGGCC-G is Pathogenic according to our data. Variant chr2-227284229-GAGTAAAGGGCC-G is described in ClinVar as Pathogenic. ClinVar VariationId is 551819.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
COL4A3	NM_000091.5	c.2768_2778delTAAAGGGCCAG	p.Val923GlufsTer13	frameshift_variant	Exon 34 of 52	ENST00000396578.8	NP_000082.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL4A3	ENST00000396578.8	c.2768_2778delTAAAGGGCCAG	p.Val923GlufsTer13	frameshift_variant	Exon 34 of 52	1	NM_000091.5	ENSP00000379823.3

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152138 Hom.: 0 Cov.: 32

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000201 AC: 5 AN: 249328 AF XY: 0.0000222

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: 0.0000442

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000814 AC: 119 AN: 1461830 Hom.: 0 AF XY: 0.0000770 AC XY: 56 AN XY: 727228

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53398

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.000106 AC: 118 AN: 1111980

Other (OTH) AF: 0.0000166 AC: 1 AN: 60392

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152138 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74320

African (AFR) AF: 0.0000241 AC: 1 AN: 41456

American (AMR) AF: 0.00 AC: 0 AN: 15260

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5186

South Asian (SAS) AF: 0.00 AC: 0 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10606

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000294 AC: 2 AN: 68022

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000227

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

Dec 27, 2019

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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; This variant is associated with the following publications: (PMID: 30665703, 24052634, 24854265) -

Feb 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Val923Glufs*13) 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 (rs766306957, gnomAD 0.005%). This premature translational stop signal has been observed in individual(s) with Alport syndrome (PMID: 24052634, 24854265). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 551819). For these reasons, this variant has been classified as Pathogenic. -

Sep 20, 2017

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Autosomal recessive Alport syndrome Pathogenic:2

May 08, 2017

Counsyl

Significance: 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. -

Feb 04, 2019

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: COL4A3 c.2768_2778del11 (p.Val923GlufsX13) 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. The variant allele was found at a frequency of 2.4e-05 in 246024 control chromosomes (gnomAD). c.2768_2778del11 has been reported in the literature in homozygous and compound heterozygous individuals affected with Alport Syndrome, autosomal recessive (Storey 2013, Moriniere 2014). These data indicate that the variant is 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, and both of them classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Inborn genetic diseases Pathogenic:1

Apr 18, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2768_2778del11 (p.V923Efs*13) alteration, located in exon 34 (coding exon 34) of the COL4A3 gene, consists of a deletion of 11 nucleotides from position 2768 to 2778, causing a translational frameshift with a predicted alternate stop codon after 13 amino acids. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. Based on data from gnomAD, this allele has an overall frequency of 0.002% (5/249328) total alleles studied. The highest observed frequency was 0.004% (5/113144) of European (non-Finnish) alleles. This variant has been identified in the homozygous state and in conjunction with other COL4A3 variants in individuals suspected of having Alport syndrome based on clinical features or based on glomerular basement membrane appearance (Storey, 2013; Morinière, 2014). Based on the available evidence, this alteration is classified as pathogenic. -

Hematuria, benign familial, 2;C5882663:Autosomal dominant Alport syndrome;C5882699:Alport syndrome 3b, autosomal recessive Pathogenic:1

Jun 15, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Alport syndrome Pathogenic:1

Sep 16, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		6.1
Mutation Taster		=3/197	disease causing (ClinVar)

Splicing

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

Other links and lift over

dbSNP: rs766306957; hg19: chr2-228148945;