rs756966358

Variant summary

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

The NM_001849.4(COL6A2):​c.1181G>C​(p.Gly394Ala) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.000000686 in 1,457,758 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 34)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

COL6A2
NM_001849.4 missense, splice_region

Scores

11
7
1
Splicing: ADA: 0.003820
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.57

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: 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, 0.976

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL6A2NM_001849.4 linkc.1181G>C p.Gly394Ala missense_variant, splice_region_variant Exon 14 of 28 ENST00000300527.9 NP_001840.3
COL6A2NM_058174.3 linkc.1181G>C p.Gly394Ala missense_variant, splice_region_variant Exon 14 of 28 ENST00000397763.6 NP_478054.2
COL6A2NM_058175.3 linkc.1181G>C p.Gly394Ala missense_variant, splice_region_variant Exon 14 of 28 NP_478055.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL6A2ENST00000300527.9 linkc.1181G>C p.Gly394Ala missense_variant, splice_region_variant Exon 14 of 28 1 NM_001849.4 ENSP00000300527.4
COL6A2ENST00000397763.6 linkc.1181G>C p.Gly394Ala missense_variant, splice_region_variant Exon 14 of 28 5 NM_058174.3 ENSP00000380870.1
COL6A2ENST00000409416.6 linkc.1181G>C p.Gly394Ala missense_variant, splice_region_variant Exon 13 of 27 5 ENSP00000387115.1

Frequencies

GnomAD3 genomes
Cov.:
34
GnomAD2 exomes
AF:
0.00000401
AC:
1
AN:
249540
AF XY:
0.00
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:
0.00
Gnomad OTH exome
AF:
0.000164
GnomAD4 exome
AF:
6.86e-7
AC:
1
AN:
1457758
Hom.:
0
Cov.:
30
AF XY:
0.00000138
AC XY:
1
AN XY:
725444
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33434
American (AMR)
AF:
0.00
AC:
0
AN:
44678
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26066
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39596
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86214
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52276
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
9.01e-7
AC:
1
AN:
1109488
Other (OTH)
AF:
0.00
AC:
0
AN:
60242
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
Heterozygous variant carriers
0
0
1
1
2
2
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
Cov.:
34
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
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
Aug 27, 2023
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: 572135). This variant has not been reported in the literature in individuals affected with COL6A2-related conditions. This variant is present in population databases (rs756966358, gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 394 of the COL6A2 protein (p.Gly394Ala). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. This variant disrupts the p.Gly394 amino acid residue in COL6A2. Other variant(s) that disrupt this residue have been observed in individuals with COL6A2-related conditions (PMID: 20976770, 24038877), which suggests that this may be a clinically significant amino acid residue. This variant disrupts the triple helix domain of COL6A2. Glycine residues within the Gly-Xaa-Yaa repeats of the triple helix domain are required for the structure and stability of fibrillar collagens (PMID: 7695699, 8218237, 19344236). In COL6A2, missense variants at these glycine residues are significantly enriched in individuals with autosomal dominant disease (PMID: 15689448, 24038877) compared to the general population (ExAC). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.42
BayesDel_addAF
Pathogenic
0.55
D
BayesDel_noAF
Pathogenic
0.56
CADD
Uncertain
25
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.72
D;.;.;.
Eigen
Pathogenic
0.75
Eigen_PC
Uncertain
0.59
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.93
D;D;.;D
M_CAP
Pathogenic
0.96
D
MetaRNN
Pathogenic
0.98
D;D;D;D
MetaSVM
Pathogenic
0.98
D
MutationAssessor
Pathogenic
3.9
H;H;H;H
PhyloP100
5.6
PrimateAI
Pathogenic
0.84
D
PROVEAN
Uncertain
-4.0
D;D;D;D
REVEL
Pathogenic
0.96
Sift
Pathogenic
0.0
D;D;D;D
Sift4G
Uncertain
0.042
D;D;D;D
Polyphen
1.0
D;D;D;D
Vest4
0.69
MutPred
0.81
Loss of catalytic residue at G394 (P = 0.1107);Loss of catalytic residue at G394 (P = 0.1107);Loss of catalytic residue at G394 (P = 0.1107);Loss of catalytic residue at G394 (P = 0.1107);
MVP
1.0
MPC
0.63
ClinPred
1.0
D
GERP RS
4.6
Varity_R
0.80
gMVP
0.91
Mutation Taster
=12/88
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.0038
dbscSNV1_RF
Benign
0.058
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: rs756966358; hg19: chr21-47538945; API