2-237344687-C-T

Position:

chr2-237344687-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PM5

The ENST00000295550.9(COL6A3):c.7331G>A(p.Arg2444Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,610,148 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. R2444W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

COL6A3
ENST00000295550.9 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 7.76

Variant links:

Genes affected

COL6A3 (HGNC:2213): (collagen type VI alpha 3 chain) This gene encodes the alpha-3 chain, one of the three alpha chains of type VI collagen, a beaded filament collagen found in most connective tissues. The alpha-3 chain of type VI collagen is much larger than the alpha-1 and -2 chains. This difference in size is largely due to an increase in the number of subdomains, similar to von Willebrand Factor type A domains, that are found in the amino terminal globular domain of all the alpha chains. These domains have been shown to bind extracellular matrix proteins, an interaction that explains the importance of this collagen in organizing matrix components. Mutations in the type VI collagen genes are associated with Bethlem myopathy, a rare autosomal dominant proximal myopathy with early childhood onset. Mutations in this gene are also a cause of Ullrich congenital muscular dystrophy, also referred to as Ullrich scleroatonic muscular dystrophy, an autosomal recessive congenital myopathy that is more severe than Bethlem myopathy. Multiple transcript variants have been identified, but the full-length nature of only some of these variants has been described. [provided by RefSeq, Jun 2009]

COL6A3 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr2-237344687-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 476555.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
COL6A3	NM_004369.4 linkuse as main transcript	c.7331G>A	p.Arg2444Gln	missense_variant	36/44	ENST00000295550.9	NP_004360.2
COL6A3	NM_057167.4 linkuse as main transcript	c.6713G>A	p.Arg2238Gln	missense_variant	35/43		NP_476508.2
COL6A3	NM_057166.5 linkuse as main transcript	c.5510G>A	p.Arg1837Gln	missense_variant	33/41		NP_476507.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL6A3	ENST00000295550.9 linkuse as main transcript	c.7331G>A	p.Arg2444Gln	missense_variant	36/44	1	NM_004369.4	ENSP00000295550	P1	P12111-1

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152144

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00768

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000401

AC:

AN:

249092

Hom.:

AF XY:

0.00

AC XY:

AN XY:

134938

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000886

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000823

AC:

AN:

1458004

Hom.:

Cov.:

AF XY:

0.00000552

AC XY:

AN XY:

724780

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000901

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000526

AC:

AN:

152144

Hom.:

Cov.:

AF XY:

0.0000807

AC XY:

AN XY:

74314

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000283

Hom.:

Bravo

AF:

0.0000982

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Bethlem myopathy 1A

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 18, 2020

This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with glutamine at codon 2444 of the COL6A3 protein (p.Arg2444Gln). The arginine residue is highly conserved and there is a small physicochemical difference between arginine and glutamine. This variant has not been reported in the literature in individuals with COL6A3-related conditions. 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jan 24, 2020

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.61

BayesDel_addAF

Pathogenic

0.27

BayesDel_noAF

Pathogenic

0.15

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.65

.;D;.;T;.

Eigen

Pathogenic

0.77

Eigen_PC

Pathogenic

0.71

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.97

D;D;D;D;.

M_CAP

Uncertain

0.24

MetaRNN

Uncertain

0.63

D;D;D;D;D

MetaSVM

Uncertain

0.61

MutationAssessor

Pathogenic

3.0

.;M;.;.;.

MutationTaster

Benign

1.0

D;D;D;D;D;D

PrimateAI

Uncertain

0.66

PROVEAN

Uncertain

-3.3

D;D;D;.;D

REVEL

Pathogenic

0.73

Sift

Uncertain

0.020

D;D;D;.;D

Sift4G

Pathogenic

0.0

D;D;D;D;D

Polyphen

1.0

D;D;.;.;D

Vest4

0.80

MutPred

0.78

.;Loss of solvent accessibility (P = 0.0703);.;.;.;

MVP

0.89

MPC

0.17

ClinPred

0.97

GERP RS

5.2

Varity_R

0.33

gMVP

0.82

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