rs113994108

Positions:

• chr13-110181326-C-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PP2 PP3_Strong PP5

The ENST00000375820.10(COL4A1):​c.2159G>A​(p.Gly720Asp) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,762 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 Likely pathogenic (no stars). Synonymous variant affecting the same amino acid position (i.e. G720G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COL4A1 ENST00000375820.10 missense
• Clinical Significance: Pathogenic/Likely pathogenic no assertion criteria provided P:2 O:1
• Conservation: PhyloP100: 6.17

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 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, 6 uncertain in ENST00000375820.10
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), COL4A1. . Gene score misZ 3.0194 (greater than the threshold 3.09). Trascript score misZ 4.972 (greater than threshold 3.09). GenCC has associacion of gene with brain small vessel disease 1 with or without ocular anomalies, pontine autosomal dominant microangiopathy with leukoencephalopathy, muscular dystrophy-dystroglycanopathy, type A, microangiopathy and leukoencephalopathy, pontine, autosomal dominant, familial porencephaly, autosomal dominant familial hematuria-retinal arteriolar tortuosity-contractures syndrome, retinal arterial tortuosity.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 13-110181326-C-T is Pathogenic according to our data. Variant chr13-110181326-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 17421.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL4A1	NM_001845.6	c.2159G>A	p.Gly720Asp	missense_variant	29/52	ENST00000375820.10	NP_001836.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL4A1	ENST00000375820.10	c.2159G>A	p.Gly720Asp	missense_variant	29/52	1	NM_001845.6	ENSP00000364979	P1
COL4A1	ENST00000649738.1	n.2289G>A		non_coding_transcript_exon_variant	29/31

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461762 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727178

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2 Other:1

Revision: no assertion criteria provided

Submissions by phenotype

Brain small vessel disease 1 with or without ocular anomalies Pathogenic:1 Other:1

not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Aug 01, 2007	- -

Developmental cataract Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

Dept. Genetics and Cancer, Menzies Institute for Medical Research, University of Tasmania

May 01, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.91	D
Eigen	Pathogenic	0.82
Eigen_PC	Uncertain	0.64
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.97	D
M_CAP	Pathogenic	0.93	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.9	H
MutationTaster	Benign	1.0	A;A
PrimateAI	Uncertain	0.79	T
PROVEAN	Pathogenic	-5.8	D
REVEL	Pathogenic	0.94
Sift	Uncertain	0.011	D
Sift4G	Uncertain	0.0040	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.91		Gain of catalytic residue at P725 (P = 0.0057);
MVP		0.98
MPC		0.57
ClinPred		1.0	D
GERP RS		4.3
Varity_R		0.84
gMVP		1.0

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

Publications

LitVar

Other links and lift over

dbSNP: rs113994108; hg19: chr13-110833673;