2-227051116-G-T

Position:

• chr2-227051116-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_000092.5(COL4A4):​c.3011C>A​(p.Pro1004Gln) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1004L) has been classified as Benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: COL4A4 NM_000092.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.51

Genes affected

COL4A4 (HGNC:2206): (collagen type IV alpha 4 chain) This gene encodes one of the six subunits of type IV collagen, the major structural component of basement membranes. This particular collagen IV subunit, however, is only found in a subset of basement membranes. 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. Mutations in this gene are associated with type II autosomal recessive Alport syndrome (hereditary glomerulonephropathy) and with familial benign hematuria (thin basement membrane disease). Two transcripts, differing only in their transcription start sites, have been identified for this gene and, as is common for collagen genes, multiple polyadenylation sites are found in the 3' UTR. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 4 uncertain in NM_000092.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.755

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL4A4	NM_000092.5	c.3011C>A	p.Pro1004Gln	missense_variant	33/48	ENST00000396625.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL4A4	ENST00000396625.5	c.3011C>A	p.Pro1004Gln	missense_variant	33/48	5	NM_000092.5	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 52

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.040
CADD	Benign	20
DANN	Benign	0.94
DEOGEN2	Uncertain	0.66	D
Eigen	Uncertain	0.29
Eigen_PC	Benign	0.22
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.89	D
M_CAP	Pathogenic	0.45	D
MetaRNN	Pathogenic	0.76	D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Benign	1.4	L
MutationTaster	Benign	1.0	D;D
PrimateAI	Benign	0.45	T
PROVEAN	Pathogenic	-5.9	D
REVEL	Uncertain	0.59
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.54
MutPred		0.19		Gain of MoRF binding (P = 0.0286);
MVP		0.85
MPC		0.13
ClinPred		0.89	D
GERP RS		4.6
Varity_R		0.39
gMVP		0.25

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1800517; hg19: chr2-227915832;