rs112172548

chr2-237376978-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_004369.4(COL6A3):c.2864G>A(p.Arg955His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000731 in 1,614,122 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/20 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. R955C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000072 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000073 (0 hom.)
• Consequence: COL6A3 NM_004369.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 0.158

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.34483832).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL6A3	NM_004369.4	c.2864G>A	p.Arg955His	missense_variant	7/44	ENST00000295550.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL6A3	ENST00000295550.9	c.2864G>A	p.Arg955His	missense_variant	7/44	1	NM_004369.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000723 AC: 11 AN: 152228 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000724

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.0000942

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000735

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000716 AC: 18 AN: 251458 Hom.: 0 AF XY: 0.0000736 AC XY: 10 AN XY: 135914

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000462

Gnomad NFE exome AF: 0.000106

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000732 AC: 107 AN: 1461894 Hom.: 0 Cov.: 32 AF XY: 0.0000811 AC XY: 59 AN XY: 727248

Gnomad4 AFR exome AF: 0.0000597

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.0000749

Gnomad4 NFE exome AF: 0.0000827

Gnomad4 OTH exome AF: 0.0000828

GnomAD4 genome AF: 0.0000723 AC: 11 AN: 152228 Hom.: 0 Cov.: 33 AF XY: 0.0000941 AC XY: 7 AN XY: 74370

Gnomad4 AFR AF: 0.0000724

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000192

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.0000942

Gnomad4 NFE AF: 0.0000735

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000153 Hom.: 0

Bravo AF: 0.0000529

TwinsUK AF: 0.00 AC: 0

ALSPAC AF: 0.000259 AC: 1

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.0000906 AC: 11

EpiCase AF: 0.000218

EpiControl AF: 0.000237

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Nov 04, 2021	Observed in a patient reported to have intermediate collagen VI-related myopathy who harbored a second variant in the COL6A3 gene, however, it is unclear if comprehensive genetic testing was completed (Foley et al., 2013); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 24271325) -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Dec 19, 2016	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Apr 20, 2022	- -

Bethlem myopathy 1A Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Nov 29, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.079
BayesDel_addAF	Benign	-0.25	T
BayesDel_noAF	Benign	-0.38
Cadd	Benign	15
Dann	Uncertain	1.0
Eigen	Benign	-0.56
Eigen_PC	Benign	-0.63
FATHMM_MKL	Benign	0.032	N
LIST_S2	Uncertain	0.88	D;D;D;D;.;T;T
M_CAP	Pathogenic	0.47	D
MetaRNN	Benign	0.34	T;T;T;T;T;T;T
MetaSVM	Benign	-0.56	T
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N
PrimateAI	Benign	0.25	T
PROVEAN	Benign	-0.59	N;N;N;.;N;N;N
REVEL	Pathogenic	0.72
Sift	Benign	0.15	T;T;T;.;T;T;T
Sift4G	Benign	0.083	T;D;T;T;T;T;T
Polyphen		1.0	D;B;.;.;D;.;.
Vest4		0.062
MVP		0.78
MPC		0.21
ClinPred		0.96	D
GERP RS		2.6
Varity_R		0.031
gMVP		0.38

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

Other links and lift over

dbSNP: rs112172548; hg19: chr2-238285621; COSMIC: COSV55094037; COSMIC: COSV55094037;