chr13-110173906-C-T

Position:

• chr13-110173906-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_001845.6(COL4A1):​c.3499G>A​(p.Glu1167Lys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. E1167E) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL4A1 NM_001845.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.53

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 Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_001845.6
• 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL4A1	NM_001845.6	c.3499G>A	p.Glu1167Lys	missense_variant	40/52	ENST00000375820.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL4A1	ENST00000375820.10	c.3499G>A	p.Glu1167Lys	missense_variant	40/52	1	NM_001845.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 07, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.27
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.43	T
Eigen	Uncertain	0.65
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D
M_CAP	Pathogenic	0.35	D
MetaRNN	Uncertain	0.58	D
MetaSVM	Uncertain	0.75	D
MutationAssessor	Benign	1.9	L
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-2.0	N
REVEL	Uncertain	0.60
Sift	Benign	0.078	T
Sift4G	Benign	0.19	T
Polyphen		1.0	D
Vest4		0.40
MutPred		0.44		Gain of catalytic residue at E1167 (P = 2e-04);
MVP		0.72
MPC		1.3
ClinPred		0.94	D
GERP RS		5.4
Varity_R		0.48
gMVP		0.80

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs1555302739; hg19: chr13-110826253;