NM_001849.4:c.2633C>T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PP3_ModeratePP5

The NM_001849.4(COL6A2):​c.2633C>T​(p.Ala878Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000076 in 1,579,748 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 Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. A878A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 34)
Exomes 𝑓: 0.0000035 ( 0 hom. )

Consequence

COL6A2
NM_001849.4 missense

Scores

6
12
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:4

Conservation

PhyloP100: 5.91

Publications

0 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: Uncertain_significance. The variant received 5 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 6 uncertain in NM_001849.4
PP3
MetaRNN computational evidence supports a deleterious effect, 0.93
PP5
Variant 21-46132125-C-T is Pathogenic according to our data. Variant chr21-46132125-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 210748.We mark this variant Likely_pathogenic, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL6A2NM_001849.4 linkc.2633C>T p.Ala878Val 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.2633C>T p.Ala878Val missense_variant Exon 28 of 28 1 NM_001849.4 ENSP00000300527.4 P12110-1

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152216
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.000121
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000161
AC:
3
AN:
186134
AF XY:
0.00000983
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:
0.0000374
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000350
AC:
5
AN:
1427532
Hom.:
0
Cov.:
33
AF XY:
0.00000424
AC XY:
3
AN XY:
708070
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32492
American (AMR)
AF:
0.00
AC:
0
AN:
39704
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25562
East Asian (EAS)
AF:
0.00
AC:
0
AN:
37234
South Asian (SAS)
AF:
0.0000242
AC:
2
AN:
82604
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
47552
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5738
European-Non Finnish (NFE)
AF:
0.00000273
AC:
3
AN:
1097504
Other (OTH)
AF:
0.00
AC:
0
AN:
59142
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.445
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000460
AC:
7
AN:
152216
Hom.:
0
Cov.:
34
AF XY:
0.0000269
AC XY:
2
AN XY:
74354
show subpopulations
African (AFR)
AF:
0.000121
AC:
5
AN:
41444
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.511
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00000573
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.00000843
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:3
Jan 26, 2016
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 01, 2022
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 08, 2021
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Bethlem myopathy 1A Pathogenic:1
May 15, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 878 of the COL6A2 protein (p.Ala878Val). This variant is present in population databases (rs774521989, gnomAD 0.01%). This missense change has been observed in individual(s) with clinical features of autosomal recessive COL6A2-related conditions (PMID: 33481221; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 210748). 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%. For these reasons, this variant has been classified as Pathogenic. -

Myopathy Pathogenic:1
Jan 07, 2015
Genetic Services Laboratory, University of Chicago
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Ullrich congenital muscular dystrophy 1A Uncertain:1
May 04, 2022
Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:curation

The homozygous p.Ala878Val variant in COL6A2 was identified by our study in 1 individual with Ullrich congenital muscular dystrophy 1. The variant has not been previously reported in individuals with Ullrich congenital muscular dystrophy 1 but has been identified in 0.01% (2/19182) of African chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs774521989). Although this variant has been seen in the general population, its frequency is not high enough to rule out a pathogenic role. This variant has also been reported in ClinVar (Variation ID: 210748) as likely pathogenic by Genetic Services Laboratory, University of Chicago, and as uncertain significance by Invitae and EGL Genetic Diagnostics, Eurofins Clinical Diagnostics. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PP3, PM3_supporting (Richards 2015). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.93
BayesDel_addAF
Pathogenic
0.21
D
BayesDel_noAF
Pathogenic
0.18
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.68
D
Eigen
Uncertain
0.51
Eigen_PC
Uncertain
0.40
FATHMM_MKL
Uncertain
0.89
D
LIST_S2
Uncertain
0.92
D
M_CAP
Pathogenic
0.51
D
MetaRNN
Pathogenic
0.93
D
MetaSVM
Uncertain
0.51
D
MutationAssessor
Uncertain
2.5
M
PhyloP100
5.9
PrimateAI
Uncertain
0.72
T
PROVEAN
Uncertain
-2.8
D
REVEL
Pathogenic
0.77
Sift
Uncertain
0.0060
D
Sift4G
Uncertain
0.010
D
Polyphen
1.0
D
Vest4
0.76
MutPred
0.62
Loss of disorder (P = 0.1004);
MVP
0.91
MPC
0.61
ClinPred
0.96
D
GERP RS
4.2
Varity_R
0.35
gMVP
0.89
Mutation Taster
=62/38
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs774521989; hg19: chr21-47552039; COSMIC: COSV52424098; COSMIC: COSV52424098; API