rs374447921

chr2-237374720-G-Achr2-237374720-G-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_004369.4(COL6A3):c.3371C>T(p.Ala1124Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000192 in 1,613,318 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1124E) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: COL6A3 NM_004369.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:2
• Conservation: PhyloP100: 1.50

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 Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.14229491).
• BP6: Variant 2-237374720-G-A is Benign according to our data. Variant chr2-237374720-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 290337.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=3}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL6A3	NM_004369.4	c.3371C>T	p.Ala1124Val	missense_variant	8/44	ENST00000295550.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL6A3	ENST00000295550.9	c.3371C>T	p.Ala1124Val	missense_variant	8/44	1	NM_004369.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152146 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000239 AC: 6 AN: 250822 Hom.: 0 AF XY: 0.0000295 AC XY: 4 AN XY: 135594

Gnomad AFR exome AF: 0.0000616

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000109

Gnomad SAS exome AF: 0.0000654

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000178 AC: 26 AN: 1461054 Hom.: 0 Cov.: 32 AF XY: 0.0000179 AC XY: 13 AN XY: 726690

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000134

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000101

Gnomad4 SAS exome AF: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000990

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000328 AC: 5 AN: 152264 Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3 AN XY: 74440

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000567

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.0000330 AC: 4

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Oct 25, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Sep 14, 2016	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Greenwood Genetic Center Diagnostic Laboratories, Greenwood Genetic Center	Nov 24, 2021	PM2 -

Bethlem myopathy 1A Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Nov 16, 2023

- -

Collagen 6-related myopathy Benign:1

Likely 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 likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.33	T
BayesDel_noAF	Benign	-0.49
Cadd	Benign	21
Dann	Uncertain	1.0
Eigen	Benign	-0.27
Eigen_PC	Benign	-0.30
FATHMM_MKL	Benign	0.41	N
LIST_S2	Benign	0.83	T;T;D;D;.;T;T
M_CAP	Benign	0.017	T
MetaRNN	Benign	0.14	T;T;T;T;T;T;T
MetaSVM	Benign	-0.85	T
MutationTaster	Benign	0.99	N;N;N;N;N;N;N;N
PrimateAI	Benign	0.40	T
PROVEAN	Uncertain	-3.1	D;D;D;.;D;N;D
REVEL	Benign	0.10
Sift	Benign	0.037	D;D;D;.;D;D;D
Sift4G	Uncertain	0.0030	D;D;D;D;D;D;D
Polyphen		0.85	P;B;.;.;P;.;.
Vest4		0.091
MVP		0.72
MPC		0.28
ClinPred		0.18	T
GERP RS		4.3
Varity_R		0.20
gMVP		0.73

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: rs374447921; hg19: chr2-238283363; COSMIC: COSV55085265; COSMIC: COSV55085265;