chr2-227290008-G-A

Variant names:

• chr2-227290008-G-A
• rs1553762113
• NM_000091.5:c.2990G>A

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1 PM2 PP3_Strong PP5_Very_Strong

The NM_000091.5(COL4A3):​c.2990G>A​(p.Gly997Glu) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,788 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: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COL4A3 NM_000091.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4 U:1
• Conservation: PhyloP100: 6.31
• Publications: 2 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.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_000091.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 2-227290008-G-A is Pathogenic according to our data. Variant chr2-227290008-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 551881.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.2990G>A	p.Gly997Glu	missense_variant	Exon 36 of 52	ENST00000396578.8	NP_000082.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL4A3	ENST00000396578.8	c.2990G>A	p.Gly997Glu	missense_variant	Exon 36 of 52	1	NM_000091.5	ENSP00000379823.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461788 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727198

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111938

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal recessive Alport syndrome Pathogenic:2 Uncertain:1

-

Precision Medicine Center, Zhengzhou University

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

PM1:Located in a mutational hot spot PM2:not found in gnomAD PP1:Cosegregation with disease in multiple affected family members PP3:Multiple lines of computational evidence support a deleterious effect on the gene or gene product -

May 18, 2017

Counsyl

Significance: Uncertain significance

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. -

Sep 26, 2023

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.2990G>A (p.Gly997Glu) results in a non-conservative amino acid change located in the Collagen triple helix repeat (IPR008160) of the encoded protein sequence and is predicted to disrupt a critical Gly residue at position 1 of a Gly-X-Y repeat in the collagenous domain of the collagen IV alpha 3 chain (PMID: 33854215). Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 249520 control chromosomes (gnomAD). c.2990G>A has been reported in the literature in multiple individuals affected with both autosomal recessive and autosomal dominant Alport Syndrome (e.g., Xie_2014, Zhang_2021). These data indicate that the variant is very likely to be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 25596306, 33772369). Two submitters have reported clinical-significance assessments for this variant to ClinVar after 2014. One submitter classified the variant as pathogenic, and one submitter classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as pathogenic. -

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

-

Juno Genomics, Hangzhou Juno Genomics, Inc

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_Supporting+PP3_Strong+PS4_Supporting+PP1_Strong+PP4 -

not provided Pathogenic:1

Aug 24, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense change has been observed in individuals with clinical features of Alport syndrome and autosomal recessive Alport syndrome (PMID: 25381091, 25596306, 28542346). It has also been observed to segregate with disease in related individuals. For these reasons, this variant has been classified as Pathogenic. 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 COL4A3 protein function. ClinVar contains an entry for this variant (Variation ID: 551881). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 997 of the COL4A3 protein (p.Gly997Glu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.80
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.68	D;.
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D;D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.4	H;.
PhyloP100		6.3
PrimateAI	Uncertain	0.70	T
PROVEAN	Pathogenic	-6.3	D;D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.98
MutPred		0.99		Loss of methylation at R996 (P = 0.0342);.;
MVP		0.96
MPC		0.25
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.97
gMVP		1.0
Mutation Taster		=5/95	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

Other links and lift over

dbSNP: rs1553762113; hg19: chr2-228154724;