21-46132019-C-T

Position:

chr21-46132019-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM5PP3_Strong

The ENST00000300527.9(COL6A2):c.2527C>T(p.Arg843Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000217 in 1,609,246 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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. R843Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 34)

Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

COL6A2
ENST00000300527.9 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 0.0790

Variant links:

Genes affected

COL6A2 (HGNC:2212): (collagen type VI alpha 2 chain) This gene encodes one of the three alpha chains of type VI collagen, a beaded filament collagen found in most connective tissues. The product of this gene contains several domains similar to von Willebrand Factor type A domains. 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 this gene are associated with Bethlem myopathy and Ullrich scleroatonic muscular dystrophy. Three transcript variants have been identified for this gene. [provided by RefSeq, Jul 2008]

COL6A2 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM5

Other missense variant is known to change same aminoacid residue: Variant chr21-46132020-G-A is described in Lovd as [Pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.952

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL6A2	NM_001849.4 linkuse as main transcript	c.2527C>T	p.Arg843Trp	missense_variant	28/28	ENST00000300527.9	NP_001840.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL6A2	ENST00000300527.9 linkuse as main transcript	c.2527C>T	p.Arg843Trp	missense_variant	28/28	1	NM_001849.4	ENSP00000300527	P1	P12110-1

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152182

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000293

AC:

AN:

238914

Hom.:

AF XY:

0.0000305

AC XY:

AN XY:

131230

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000585

Gnomad ASJ exome

AF:

0.000102

Gnomad EAS exome

AF:

0.0000560

Gnomad SAS exome

AF:

0.0000329

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000186

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000206

AC:

AN:

1457064

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

725108

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000448

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000198

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152182

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74344

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000227

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000117

AC:

ExAC

AF:

0.0000415

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Aug 25, 2019	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Dec 19, 2016	- -

Bethlem myopathy 1A

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 19, 2024

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 843 of the COL6A2 protein (p.Arg843Trp). This variant is present in population databases (rs376880198, gnomAD 0.01%). This missense change has been observed in individual(s) with limb-girdle muscular dystrophy and Bethlem myopathy (PMID: 19949035, 30564623). ClinVar contains an entry for this variant (Variation ID: 242692). 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 expected to disrupt COL6A2 protein function with a positive predictive value of 80%. This variant disrupts the p.Arg843 amino acid residue in COL6A2. Other variant(s) that disrupt this residue have been observed in individuals with COL6A2-related conditions (PMID: 24271325), which suggests that this may be a clinically significant amino acid residue. 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

Pathogenic

0.78

BayesDel_addAF

Pathogenic

0.22

BayesDel_noAF

Pathogenic

0.25

CADD

Uncertain

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.67

Eigen

Benign

-0.011

Eigen_PC

Benign

-0.13

FATHMM_MKL

Benign

0.64

LIST_S2

Pathogenic

0.98

M_CAP

Pathogenic

0.53

MetaRNN

Pathogenic

0.95

MetaSVM

Uncertain

0.28

MutationAssessor

Uncertain

2.5

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.58

PROVEAN

Uncertain

-3.9

REVEL

Pathogenic

0.76

Sift

Uncertain

0.019

Sift4G

Uncertain

0.010

Polyphen

1.0

Vest4

0.84

MVP

0.95

MPC

0.62

ClinPred

0.88

GERP RS

0.70

Varity_R

0.26

gMVP

0.84

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