13-110187203-G-T

Variant names:

• chr13-110187203-G-T
• rs536174
• NM_001845.6:c.1663C>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1 PM2

The NM_001845.6(COL4A1):​c.1663C>A​(p.Pro555Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,846 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P555S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COL4A1 NM_001845.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.25
• Publications: 30 publications found

Genes affected

COL4A1 (HGNC:2202): (collagen type IV alpha 1 chain) This gene encodes a type IV collagen alpha protein. Type IV collagen proteins are integral components of basement membranes. This gene shares a bidirectional promoter with a paralogous gene on the opposite strand. The protein consists of an amino-terminal 7S domain, a triple-helix forming collagenous domain, and a carboxy-terminal non-collagenous domain. It functions as part of a heterotrimer and interacts with other extracellular matrix components such as perlecans, proteoglycans, and laminins. In addition, proteolytic cleavage of the non-collagenous carboxy-terminal domain results in a biologically active fragment known as arresten, which has anti-angiogenic and tumor suppressor properties. Mutations in this gene cause porencephaly, cerebrovascular disease, and renal and muscular defects. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2014]

COL4A1 Gene-Disease associations (from GenCC):

• brain small vessel disease 1 with or without ocular anomalies

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, G2P, Genomics England PanelApp
• autosomal dominant familial hematuria-retinal arteriolar tortuosity-contractures syndrome

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Genomics England PanelApp, Orphanet
• microangiopathy and leukoencephalopathy, pontine, autosomal dominant

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• familial porencephaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• pontine autosomal dominant microangiopathy with leukoencephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• retinal arterial tortuosity

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• muscular dystrophy-dystroglycanopathy, type A

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_001845.6
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001845.6. 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
	COL4A1	NM_001845.6	MANE Select	c.1663C>A	p.Pro555Thr	missense	Exon 25 of 52	NP_001836.3	P02462-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL4A1	ENST00000375820.10	TSL:1 MANE Select	c.1663C>A	p.Pro555Thr	missense	Exon 25 of 52	ENSP00000364979.4	P02462-1
	COL4A1	ENST00000650424.2		c.1663C>A	p.Pro555Thr	missense	Exon 25 of 52	ENSP00000497477.2	A0A3B3ISV3
	COL4A1	ENST00000933608.1		c.1663C>A	p.Pro555Thr	missense	Exon 25 of 51	ENSP00000603667.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152172 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

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

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461674 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727140

African (AFR) AF: 0.0000299 AC: 1 AN: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5730

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111900

Other (OTH) AF: 0.00 AC: 0 AN: 60378

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152172 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74338

African (AFR) AF: 0.0000483 AC: 2 AN: 41440

American (AMR) AF: 0.00 AC: 0 AN: 15282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5174

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68040

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.00000482 Hom.: 0

Bravo AF: 0.0000302

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_noAF	Benign	-0.55
CADD	Uncertain	24
LIST_S2	Uncertain	0.96	D
MetaRNN	Uncertain	0.68	D
PhyloP100		7.3
Sift4G	Uncertain	0.010	D
Vest4		0.57
gMVP		0.56

Splicing

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

Other links and lift over

dbSNP: rs536174; hg19: chr13-110839550;