2-227293192-G-C

Variant names:

• chr2-227293192-G-C
• rs765128550
• NM_000091.5:c.3212G>C

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_000091.5(COL4A3):​c.3212G>C​(p.Gly1071Ala) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.000000684 in 1,461,614 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1071E) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COL4A3 NM_000091.5 missense, splice_region
• Scores: Splicing: ADA: 0.9733
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.92
• Publications: 0 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 12 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 10 uncertain in NM_000091.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-227293192-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 562338.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 2-227293192-G-C is Pathogenic according to our data. Variant chr2-227293192-G-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2445682.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000091.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL4A3	NM_000091.5	MANE Select	c.3212G>C	p.Gly1071Ala	missense splice_region	Exon 38 of 52	NP_000082.2	Q01955-1
	MFF-DT	NR_102371.1		n.244-11403C>G		intron	N/A

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL4A3	ENST00000396578.8	TSL:1 MANE Select	c.3212G>C	p.Gly1071Ala	missense splice_region	Exon 38 of 52	ENSP00000379823.3	Q01955-1
	MFF-DT	ENST00000439598.6	TSL:1	n.244-11403C>G		intron	N/A
	COL4A3	ENST00000871618.1		c.3212G>C	p.Gly1071Ala	missense splice_region	Exon 38 of 52	ENSP00000541677.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461614 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727124

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86248

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

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5578

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111988

Other (OTH) AF: 0.00 AC: 0 AN: 60356

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Autosomal recessive Alport syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.38
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.68	D
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.90
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
PhyloP100		5.9
PrimateAI	Uncertain	0.64	T
PROVEAN	Pathogenic	-5.3	D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.93
MutPred		0.97		Loss of relative solvent accessibility (P = 0.0071)
MVP		0.96
MPC		0.20
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.91
gMVP		0.97
Mutation Taster		=17/83	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.97
SpliceAI score (max)		0.060		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: rs765128550; hg19: chr2-228157908;