chr2-237374645-C-T

Position:

chr2-237374645-C-T

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_004369.4(COL6A3):c.3446G>A(p.Arg1149Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000457 in 1,614,144 control chromosomes in the GnomAD database, including 6 homozygotes. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1149W) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0022 ( 2 hom., cov: 33)

Exomes 𝑓: 0.00027 ( 4 hom. )

Consequence

COL6A3
NM_004369.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:5

Conservation

PhyloP100: 0.674

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 Benign. Variant got -13 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0042245984).

BP6

Variant 2-237374645-C-T is Benign according to our data. Variant chr2-237374645-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 198793.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Uncertain_significance=1, Benign=1}. Variant chr2-237374645-C-T is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00221 (336/152282) while in subpopulation AFR AF= 0.00741 (308/41564). AF 95% confidence interval is 0.00673. There are 2 homozygotes in gnomad4. There are 148 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 2 SD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL6A3	NM_004369.4 linkuse as main transcript	c.3446G>A	p.Arg1149Gln	missense_variant	8/44	ENST00000295550.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL6A3	ENST00000295550.9 linkuse as main transcript	c.3446G>A	p.Arg1149Gln	missense_variant	8/44	1	NM_004369.4	P1	P12111-1

Frequencies

GnomAD3 genomes

AF:

0.00219

AC:

333

AN:

152164

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00734

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00118

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:

0.0000735

Gnomad OTH

AF:

0.00287

GnomAD3 exomes

AF:

0.000581

AC:

146

AN:

251238

Hom.:

AF XY:

0.000449

AC XY:

AN XY:

135836

show subpopulations

Gnomad AFR exome

AF:

0.00819

Gnomad AMR exome

AF:

0.000260

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:

0.00000880

Gnomad OTH exome

AF:

0.000489

GnomAD4 exome

AF:

0.000275

AC:

402

AN:

1461862

Hom.:

Cov.:

AF XY:

0.000238

AC XY:

173

AN XY:

727234

show subpopulations

Gnomad4 AFR exome

AF:

0.00911

Gnomad4 AMR exome

AF:

0.000470

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000315

Gnomad4 OTH exome

AF:

0.000580

GnomAD4 genome

AF:

0.00221

AC:

336

AN:

152282

Hom.:

Cov.:

AF XY:

0.00199

AC XY:

148

AN XY:

74464

show subpopulations

Gnomad4 AFR

AF:

0.00741

Gnomad4 AMR

AF:

0.00111

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00284

Alfa

AF:

0.000631

Hom.:

Bravo

AF:

0.00243

ESP6500AA

AF:

0.00840

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000741

AC:

Asia WGS

AF:

0.000866

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:5

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 04, 2024

The c.3446G>A (p.R1149Q) alteration is located in exon 8 (coding exon 7) of the COL6A3 gene. This alteration results from a G to A substitution at nucleotide position 3446, causing the arginine (R) at amino acid position 1149 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not specified

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Sep 15, 2015

- -

Bethlem myopathy 1A

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 22, 2024

- -

Collagen 6-related myopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

not provided

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Mar 10, 2021

- -

COL6A3-related disorder

Benign:1

Benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Aug 13, 2019

This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.084

BayesDel_addAF

Benign

-0.40

BayesDel_noAF

Benign

-0.34

CADD

Benign

DANN

Benign

0.91

DEOGEN2

Benign

0.17

.;T;.;T;.;.;.

Eigen

Benign

-0.69

Eigen_PC

Benign

-0.69

FATHMM_MKL

Benign

0.14

LIST_S2

Uncertain

0.91

D;D;D;D;.;D;D

M_CAP

Benign

0.042

MetaRNN

Benign

0.0042

T;T;T;T;T;T;T

MetaSVM

Benign

-0.84

MutationAssessor

Benign

1.3

.;L;.;.;.;.;.

MutationTaster

Benign

1.0

N;N;N;N;N;N;N;N

PrimateAI

Benign

0.29

PROVEAN

Benign

-0.93

N;N;N;.;N;N;N

REVEL

Benign

0.19

Sift

Benign

0.19

T;T;T;.;T;T;T

Sift4G

Benign

0.21

T;T;T;T;T;T;T

Polyphen

0.76

P;B;.;.;P;.;.

Vest4

0.058

MVP

0.80

MPC

0.25

ClinPred

0.0042

GERP RS

2.2

Varity_R

0.11

gMVP

0.69

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