2-227118652-C-T

Variant names:

• chr2-227118652-C-T
• rs745672795
• NM_000092.5:c.482G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000092.5(COL4A4):​c.482G>A​(p.Gly161Asp) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,459,788 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. G161R) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: COL4A4 NM_000092.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.53
• Publications: 1 publications found

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]

COL4A4 Gene-Disease associations (from GenCC):

• autosomal recessive Alport syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Myriad Women’s Health, Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• Alport syndrome

  Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
• hematuria, benign familial, 1

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
• autosomal dominant Alport syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 6 uncertain in NM_000092.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-227118653-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 635444.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000092.5. 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
	COL4A4	NM_000092.5	MANE Select	c.482G>A	p.Gly161Asp	missense	Exon 7 of 48	NP_000083.3	P53420

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL4A4	ENST00000396625.5	TSL:5 MANE Select	c.482G>A	p.Gly161Asp	missense	Exon 7 of 48	ENSP00000379866.3	P53420
	COL4A4	ENST00000643379.1		c.482G>A	p.Gly161Asp	missense	Exon 7 of 15	ENSP00000494516.1	A0A2R8Y548
	COL4A4	ENST00000682248.1		n.583G>A		non_coding_transcript_exon	Exon 6 of 11

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000401 AC: 1 AN: 249086 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000290

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459788 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726368

African (AFR) AF: 0.00 AC: 0 AN: 33440

American (AMR) AF: 0.0000224 AC: 1 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86220

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53256

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110228

Other (OTH) AF: 0.00 AC: 0 AN: 60348

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.73
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.55
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.66	D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Pathogenic	4.6	H
PhyloP100		5.5
PrimateAI	Uncertain	0.68	T
PROVEAN	Pathogenic	-5.8	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.030	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.92		Loss of catalytic residue at G161 (P = 0.0331)
MVP		0.92
MPC		0.72
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.84
gMVP		0.98
Mutation Taster		=33/67	disease causing

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: rs745672795; hg19: chr2-227983368;