13-110306984-G-A

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 1P and 2B. PP2BP4_Moderate

The NM_001845.6(COL4A1):c.44C>T(p.Ala15Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000088 in 1,477,470 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign 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. A15T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000083 ( 0 hom. )

Consequence

COL4A1
NM_001845.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.949

Variant links:

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 links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PP2

Missense variant where missense usually causes diseases, COL4A1

BP4

Computational evidence support a benign effect (MetaRNN=0.18619075).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL4A1	NM_001845.6 linkuse as main transcript	c.44C>T	p.Ala15Val	missense_variant	1/52	ENST00000375820.10
COL4A1	NM_001303110.2 linkuse as main transcript	c.44C>T	p.Ala15Val	missense_variant	1/25

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL4A1	ENST00000375820.10 linkuse as main transcript	c.44C>T	p.Ala15Val	missense_variant	1/52	1	NM_001845.6	P1	P02462-1
COL4A1	ENST00000543140.6 linkuse as main transcript	c.44C>T	p.Ala15Val	missense_variant	1/25	1			P02462-2
COL4A2	ENST00000400163.7 linkuse as main transcript	c.-44-876G>A		intron_variant		5
COL4A1	ENST00000649738.1 linkuse as main transcript	n.174C>T		non_coding_transcript_exon_variant	1/31

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152148

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000352

AC:

AN:

85198

Hom.:

AF XY:

0.00

AC XY:

AN XY:

48366

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000473

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000322

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000830

AC:

AN:

1325322

Hom.:

Cov.:

AF XY:

0.00000459

AC XY:

AN XY:

652952

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000339

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000951

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152148

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74318

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 12, 2024

The c.44C>T (p.A15V) alteration is located in exon 1 (coding exon 1) of the COL4A1 gene. This alteration results from a C to T substitution at nucleotide position 44, causing the alanine (A) at amino acid position 15 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 07, 2023

The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt COL4A1 protein function. This variant has not been reported in the literature in individuals affected with COL4A1-related conditions. This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 15 of the COL4A1 protein (p.Ala15Val). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Benign

-0.027

BayesDel_noAF

Benign

-0.28

Cadd

Benign

Dann

Uncertain

0.98

DEOGEN2

Benign

0.16

T;.

Eigen

Benign

-0.56

Eigen_PC

Benign

-0.41

FATHMM_MKL

Benign

0.55

LIST_S2

Benign

0.56

T;T

M_CAP

Pathogenic

0.92

MetaRNN

Benign

0.19

T;T

MetaSVM

Benign

-0.64

MutationAssessor

Benign

0.34

N;N

MutationTaster

Benign

1.0

N;N;N

PrimateAI

Pathogenic

0.87

PROVEAN

Benign

0.27

N;N

REVEL

Benign

0.17

Sift

Benign

0.67

T;T

Sift4G

Benign

0.55

T;T

Polyphen

0.0020

B;.

Vest4

0.20

MutPred

0.42

Gain of catalytic residue at A15 (P = 0.0021);Gain of catalytic residue at A15 (P = 0.0021);

MVP

0.51

MPC

0.38

ClinPred

0.046

GERP RS

2.4

Varity_R

0.071

gMVP

0.31

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over