21-46132261-C-A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001849.4(COL6A2):​c.2769C>A​(p.His923Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000275 in 1,453,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H923R) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 34)
Exomes 𝑓: 0.0000028 ( 0 hom. )

Consequence

COL6A2
NM_001849.4 missense

Scores

3
16

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.824

Publications

2 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 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.25815487).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL6A2NM_001849.4 linkc.2769C>A p.His923Gln 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.2769C>A p.His923Gln missense_variant Exon 28 of 28 1 NM_001849.4 ENSP00000300527.4 P12110-1

Frequencies

GnomAD3 genomes
Cov.:
34
GnomAD2 exomes
AF:
0.0000169
AC:
4
AN:
236200
AF XY:
0.0000155
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000118
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:
0.00
GnomAD4 exome
AF:
0.00000275
AC:
4
AN:
1453882
Hom.:
0
Cov.:
34
AF XY:
0.00000276
AC XY:
2
AN XY:
723358
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33354
American (AMR)
AF:
0.0000902
AC:
4
AN:
44328
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26008
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39486
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85704
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
48660
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5758
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1110398
Other (OTH)
AF:
0.00
AC:
0
AN:
60186
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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.:
1
Bravo
AF:
0.0000151
ExAC
AF:
0.0000166
AC:
2

ClinVar

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

Submissions by phenotype

Bethlem myopathy 1A Uncertain:1
Sep 03, 2018
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The glutamine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with COL6A2-related disease. This variant is present in population databases (rs140419176, ExAC 0.03%). This sequence change replaces histidine with glutamine at codon 923 of the COL6A2 protein (p.His923Gln). The histidine residue is moderately conserved and there is a small physicochemical difference between histidine and glutamine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.20
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.31
CADD
Benign
0.83
DANN
Benign
0.87
DEOGEN2
Benign
0.28
T
Eigen
Benign
-0.60
Eigen_PC
Benign
-0.76
FATHMM_MKL
Benign
0.27
N
LIST_S2
Benign
0.47
T
M_CAP
Uncertain
0.098
D
MetaRNN
Benign
0.26
T
MetaSVM
Benign
-0.47
T
MutationAssessor
Benign
1.4
L
PhyloP100
-0.82
PrimateAI
Uncertain
0.65
T
PROVEAN
Benign
-2.3
N
REVEL
Uncertain
0.37
Sift
Benign
0.079
T
Sift4G
Benign
0.11
T
Polyphen
0.57
P
Vest4
0.18
MutPred
0.70
Gain of MoRF binding (P = 0.0764);
MVP
0.86
MPC
0.30
ClinPred
0.15
T
GERP RS
-0.043
Varity_R
0.055
gMVP
0.70
Mutation Taster
=54/46
polymorphism

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: rs140419176; hg19: chr21-47552175; API