rs778034451

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2PP3_StrongPP5

The NM_000091.5(COL4A3):c.1927G>A(p.Gly643Ser) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000868 in 1,613,180 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. G643G) has been classified as Likely benign.

Frequency

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

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

COL4A3
NM_000091.5 missense, splice_region

Scores

Splicing: ADA: 1.000

Clinical Significance

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

Conservation

PhyloP100: 6.17

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 Likely_pathogenic. Variant got 7 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 2-227273117-G-A is Pathogenic according to our data. Variant chr2-227273117-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 334764.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=2, Likely_pathogenic=1}. Variant chr2-227273117-G-A is described in Lovd as [Pathogenic]. Variant chr2-227273117-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL4A3	NM_000091.5 linkuse as main transcript	c.1927G>A	p.Gly643Ser	missense_variant, splice_region_variant	26/52	ENST00000396578.8
MFF-DT	NR_102371.1 linkuse as main transcript	n.423-4348C>T		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.1927G>A	p.Gly643Ser	missense_variant, splice_region_variant	26/52	1	NM_000091.5	P1	Q01955-1
MFF-DT	ENST00000439598.6 linkuse as main transcript	n.423-4348C>T		intron_variant, non_coding_transcript_variant		1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152148

Hom.:

Cov.:

show subpopulations

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000815

AC:

AN:

245428

Hom.:

AF XY:

0.00

AC XY:

AN XY:

133662

show subpopulations

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 SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000912

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000890

AC:

AN:

1461032

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

726792

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000989

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152148

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74318

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ExAC

AF:

0.00000828

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:1Uncertain:1

Likely pathogenic, no assertion criteria provided	research	Gharavi Laboratory, Columbia University	Sep 16, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Apr 06, 2022	This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 643 of the COL4A3 protein (p.Gly643Ser). This variant is present in population databases (rs778034451, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with COL4A3-related conditions. ClinVar contains an entry for this variant (Variation ID: 334764). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Not Available"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Autosomal recessive Alport syndrome

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Molecular Diagnostics Laboratory, M Health Fairview: University of Minnesota

Jan 23, 2018

- -

Alport syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.22

BayesDel_addAF

Uncertain

0.087

BayesDel_noAF

Uncertain

-0.010

Cadd

Pathogenic

Dann

Uncertain

0.99

DEOGEN2

Uncertain

0.68

Eigen

Uncertain

0.41

Eigen_PC

Uncertain

0.42

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.97

M_CAP

Pathogenic

0.68

MetaRNN

Pathogenic

0.99

MetaSVM

Pathogenic

0.96

MutationAssessor

Pathogenic

4.2

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.61

PROVEAN

Pathogenic

-5.4

REVEL

Pathogenic

0.68

Sift

Uncertain

0.0060

Sift4G

Uncertain

0.012

Polyphen

0.89

Vest4

0.81

MutPred

0.97

Gain of phosphorylation at G643 (P = 0.0027);

MVP

0.89

MPC

0.19

ClinPred

0.96

GERP RS

5.0

Varity_R

0.78

gMVP

0.97

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.98

SpliceAI score (max)

0.81

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.81

Position offset: 0

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