21-46132335-C-G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_001849.4(COL6A2):​c.2843C>G​(p.Thr948Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,455,446 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. T948M) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 34)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

COL6A2
NM_001849.4 missense

Scores

7
10
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.99

Publications

4 publications found
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 Gene-Disease associations (from GenCC):
  • collagen 6-related myopathy
    Inheritance: AD, AR Classification: DEFINITIVE Submitted by: ClinGen
  • Ullrich congenital muscular dystrophy 1B
    Inheritance: AR, AD Classification: DEFINITIVE Submitted by: G2P
  • Bethlem myopathy 1A
    Inheritance: AD, AR Classification: STRONG Submitted by: Genomics England PanelApp
  • Ullrich congenital muscular dystrophy 1A
    Inheritance: AD, AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • Bethlem myopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Ullrich congenital muscular dystrophy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • myosclerosis
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.955

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL6A2NM_001849.4 linkc.2843C>G p.Thr948Arg missense_variant Exon 28 of 28 ENST00000300527.9 NP_001840.3 P12110-1A0A384MDP3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL6A2ENST00000300527.9 linkc.2843C>G p.Thr948Arg missense_variant Exon 28 of 28 1 NM_001849.4 ENSP00000300527.4 P12110-1

Frequencies

GnomAD3 genomes
Cov.:
34
GnomAD2 exomes
AF:
0.00000411
AC:
1
AN:
243080
AF XY:
0.00000753
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000899
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1455446
Hom.:
0
Cov.:
35
AF XY:
0.00000276
AC XY:
2
AN XY:
724314
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33460
American (AMR)
AF:
0.00
AC:
0
AN:
44690
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26108
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39678
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86226
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
47676
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111530
Other (OTH)
AF:
0.00
AC:
0
AN:
60310
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
34
ExAC
AF:
0.00000826
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Bethlem myopathy 1A Uncertain:1
Jun 13, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

ClinVar contains an entry for this variant (Variation ID: 476477). This sequence change replaces threonine, which is neutral and polar, with arginine, which is basic and polar, at codon 948 of the COL6A2 protein (p.Thr948Arg). This variant is present in population databases (rs367980010, gnomAD 0.0009%). This missense change has been observed in individual(s) with clinical features of type VI collagenopathies (Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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
0.97
BayesDel_addAF
Pathogenic
0.36
D
BayesDel_noAF
Pathogenic
0.28
CADD
Pathogenic
27
DANN
Benign
0.92
DEOGEN2
Uncertain
0.53
D
Eigen
Uncertain
0.46
Eigen_PC
Uncertain
0.33
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Uncertain
0.93
D
M_CAP
Pathogenic
0.51
D
MetaRNN
Pathogenic
0.95
D
MetaSVM
Uncertain
0.74
D
MutationAssessor
Uncertain
2.6
M
PhyloP100
6.0
PrimateAI
Pathogenic
0.86
D
PROVEAN
Uncertain
-2.7
D
REVEL
Pathogenic
0.75
Sift
Uncertain
0.0030
D
Sift4G
Uncertain
0.0040
D
Polyphen
1.0
D
Vest4
0.87
MutPred
0.78
Gain of catalytic residue at T948 (P = 0.0087);
MVP
0.97
MPC
0.65
ClinPred
0.92
D
GERP RS
4.2
Varity_R
0.46
gMVP
0.98
Mutation Taster
=52/48
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs367980010; hg19: chr21-47552249; API