NM_001845.6:c.1819G>C

Variant names:

• chr13-110186463-C-G
• rs1555304112
• NM_001845.6:c.1819G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_001845.6(COL4A1):​c.1819G>C​(p.Gly607Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,461,464 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G607V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: COL4A1 NM_001845.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.97
• Publications: 0 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: G2P, Ambry Genetics, PanelApp Australia, Orphanet, Genomics England PanelApp
• autosomal dominant familial hematuria-retinal arteriolar tortuosity-contractures syndrome

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Ambry Genetics
• 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: Likely_pathogenic. The variant received 6 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, 9 uncertain in NM_001845.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.932

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.1819G>C	p.Gly607Arg	missense	Exon 26 of 52	NP_001836.3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL4A1	ENST00000375820.10	TSL:1 MANE Select	c.1819G>C	p.Gly607Arg	missense	Exon 26 of 52	ENSP00000364979.4
	COL4A1	ENST00000650424.2		c.1819G>C	p.Gly607Arg	missense	Exon 26 of 52	ENSP00000497477.2
	COL4A1	ENST00000933608.1		c.1819G>C	p.Gly607Arg	missense	Exon 26 of 51	ENSP00000603667.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461464 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727026

African (AFR) AF: 0.00 AC: 0 AN: 33468

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26116

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86238

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53154

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111926

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

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

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.61
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.53
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.84	D
Eigen	Pathogenic	0.68
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.77	T
M_CAP	Pathogenic	0.64	D
MetaRNN	Pathogenic	0.93	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.6	H
PhyloP100		7.0
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-5.0	D
REVEL	Pathogenic	0.71
Sift	Uncertain	0.025	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.95
MutPred		0.51		Gain of catalytic residue at Y608 (P = 0)
MVP		0.94
MPC		1.3
ClinPred		1.0	D
GERP RS		4.1
Varity_R		0.14
gMVP		0.94
Mutation Taster		=1/99	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: rs1555304112; hg19: chr13-110838810; COSMIC: COSV65423132; COSMIC: COSV65423132;