2-227279793-G-A

Position:

• chr2-227279793-G-A

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM1 PM2 PP3 PP5_Very_Strong

The NM_000091.5(COL4A3):​c.2126G>A​(p.Gly709Glu) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. G709G) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL4A3 NM_000091.5 missense, splice_region
• Scores: Splicing: ADA: 0.9992
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 4.47

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

Verdict is Pathogenic. Variant got 13 ACMG points.

• PM1: In a compositionally_biased_region Pro residues (size 19) in uniprot entity CO4A3_HUMAN there are 5 pathogenic changes around while only 1 benign (83%) in NM_000091.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.
• PP5: Variant 2-227279793-G-A is Pathogenic according to our data. Variant chr2-227279793-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 447168.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL4A3	NM_000091.5	c.2126G>A	p.Gly709Glu	missense_variant, splice_region_variant	29/52	ENST00000396578.8
MFF-DT	NR_102371.1	n.330-218C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL4A3	ENST00000396578.8	c.2126G>A	p.Gly709Glu	missense_variant, splice_region_variant	29/52	1	NM_000091.5	P1
MFF-DT	ENST00000439598.6	n.330-218C>T		intron_variant, non_coding_transcript_variant		1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Athena Diagnostics

Jun 01, 2017

- -

Autosomal dominant Alport syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

research

Molecular Biology Laboratory, Fundació Puigvert

Feb 01, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.89
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	33
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.68	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.92
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.81	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.5	H
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-6.9	D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.98		Gain of solvent accessibility (P = 0.0012);
MVP		0.95
MPC		0.25
ClinPred		1.0	D
GERP RS		6.0
Varity_R		0.98
gMVP		0.99

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.82
SpliceAI score (max)		0.30		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.30		Position offset: 3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553759430; hg19: chr2-228144509;