2-237365784-G-C

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_004369.4(COL6A3):c.5752C>G(p.Arg1918Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,890 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. R1918H) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

COL6A3
NM_004369.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.17

Publications

2 publications found

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 Gene-Disease associations (from GenCC):

Bethlem myopathy 1A
Inheritance: AD, AR, SD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Ambry Genetics
collagen 6-related myopathy
Inheritance: AD, AR Classification: DEFINITIVE Submitted by: ClinGen
Ullrich congenital muscular dystrophy 1C
Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
dystonia 27
Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED, NO_KNOWN Submitted by: Illumina, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics, Orphanet
Ullrich congenital muscular dystrophy 1A
Inheritance: AR, AD, SD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
Bethlem myopathy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Ullrich congenital muscular dystrophy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

COL6A3 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein
COL6A3	NM_004369.4 link	c.5752C>G	p.Arg1918Gly	missense_variant	Exon 12 of 44	ENST00000295550.9	NP_004360.2
COL6A3	NM_057167.4 link	c.5134C>G	p.Arg1712Gly	missense_variant	Exon 11 of 43		NP_476508.2
COL6A3	NM_057166.5 link	c.3931C>G	p.Arg1311Gly	missense_variant	Exon 9 of 41		NP_476507.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
COL6A3	ENST00000295550.9 link	c.5752C>G	p.Arg1918Gly	missense_variant	Exon 12 of 44	1	NM_004369.4	ENSP00000295550.4
COL6A3	ENST00000472056.5 link	c.3931C>G	p.Arg1311Gly	missense_variant	Exon 9 of 41	1		ENSP00000418285.1
COL6A3	ENST00000353578.9 link	c.5134C>G	p.Arg1712Gly	missense_variant	Exon 11 of 43	5		ENSP00000315873.4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461890

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727246

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1112008

Other (OTH)

AF:

0.00

AC:

AN:

60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Bethlem myopathy 1A

Uncertain:1

Mar 17, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 1918 of the COL6A3 protein (p.Arg1918Gly). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with COL6A3-related conditions. 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 COL6A3 protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.17

BayesDel_addAF

Uncertain

0.065

BayesDel_noAF

Benign

-0.14

CADD

Benign

(source)

DANN

Uncertain

0.98

DEOGEN2

Benign

0.25

.;T;.;T;.

Eigen

Benign

-0.065

Eigen_PC

Benign

0.095

FATHMM_MKL

Uncertain

0.89

LIST_S2

Benign

0.84

T;T;T;T;.

M_CAP

Benign

0.0091

MetaRNN

Uncertain

0.63

D;D;D;D;D

MetaSVM

Benign

-1.0

MutationAssessor

Uncertain

2.4

.;M;.;.;.

PhyloP100

1.2

PrimateAI

Uncertain

0.50

PROVEAN

Uncertain

-2.7

D;D;N;.;D

REVEL

Benign

0.16

Sift

Benign

0.086

T;T;T;.;T

Sift4G

Benign

0.15

T;T;T;T;T

Polyphen

0.16

B;B;.;.;B

Vest4

0.69

MutPred

0.48

.;Loss of stability (P = 0.0706);.;.;.;

MVP

0.62

MPC

0.20

ClinPred

0.57

GERP RS

4.4

Varity_R

0.14

gMVP

0.77

Mutation Taster

=54/46

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over