NM_001846.4:c.1978+31C>G

Variant names:

• chr13-110465637-C-G
• rs3825490
• NM_001846.4:c.1978+31C>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001846.4(COL4A2):​c.1978+31C>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000257 in 1,553,498 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: COL4A2 NM_001846.4 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.285
• Publications: 7 publications found

Genes affected

COL4A2 (HGNC:2203): (collagen type IV alpha 2 chain) This gene encodes one of the six subunits of type IV collagen, the major structural component of basement membranes. The C-terminal portion of the protein, known as canstatin, is an inhibitor of angiogenesis and tumor growth. 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, Jul 2008]

COL4A2 Gene-Disease associations (from GenCC):

• porencephaly 2

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• COL4A1 or COL4A2-related cerebral small vessel disease

  Inheritance: AD Classification: MODERATE Submitted by: Illumina
• familial porencephaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.87).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001846.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL4A2	NM_001846.4	MANE Select	c.1978+31C>G		intron	N/A	NP_001837.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL4A2	ENST00000360467.7	TSL:5 MANE Select	c.1978+31C>G		intron	N/A	ENSP00000353654.5
	COL4A2	ENST00000714399.1		c.2059+31C>G		intron	N/A	ENSP00000519666.1
	COL4A2	ENST00000400163.8	TSL:5	c.1978+31C>G		intron	N/A	ENSP00000383027.4

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152210 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000386

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

GnomAD2 exomes AF: 0.00000465 AC: 1 AN: 215038 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000618

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000143 AC: 2 AN: 1401170 Hom.: 0 Cov.: 24 AF XY: 0.00 AC XY: 0 AN XY: 698692

⚠️ 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: 31382

American (AMR) AF: 0.00 AC: 0 AN: 38488

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24280

East Asian (EAS) AF: 0.0000255 AC: 1 AN: 39250

South Asian (SAS) AF: 0.00 AC: 0 AN: 81868

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51988

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4828

European-Non Finnish (NFE) AF: 9.34e-7 AC: 1 AN: 1071140

Other (OTH) AF: 0.00 AC: 0 AN: 57946

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0448430), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152328 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74480

African (AFR) AF: 0.00 AC: 0 AN: 41590

American (AMR) AF: 0.00 AC: 0 AN: 15302

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.000387 AC: 2 AN: 5172

South Asian (SAS) AF: 0.00 AC: 0 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68032

Other (OTH) AF: 0.00 AC: 0 AN: 2114

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.87
CADD	Benign	1.2
DANN	Benign	0.31
PhyloP100		-0.28

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs3825490; hg19: chr13-111117984;