chr2-237336296-G-T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_004369.4(COL6A3):​c.8804C>A​(p.Ala2935Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,008 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign 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. A2935V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

COL6A3
NM_004369.4 missense

Scores

18

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -1.03

Publications

5 publications found
Variant links:
Genes affected
COL6A3 (HGNC:2213): (collagen type VI alpha 3 chain) This gene encodes the alpha-3 chain, one of the three alpha chains of type VI collagen, a beaded filament collagen found in most connective tissues. The alpha-3 chain of type VI collagen is much larger than the alpha-1 and -2 chains. This difference in size is largely due to an increase in the number of subdomains, similar to von Willebrand Factor type A domains, that are found in the amino terminal globular domain of all the alpha chains. 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 the type VI collagen genes are associated with Bethlem myopathy, a rare autosomal dominant proximal myopathy with early childhood onset. Mutations in this gene are also a cause of Ullrich congenital muscular dystrophy, also referred to as Ullrich scleroatonic muscular dystrophy, an autosomal recessive congenital myopathy that is more severe than Bethlem myopathy. Multiple transcript variants have been identified, but the full-length nature of only some of these variants has been described. [provided by RefSeq, Jun 2009]
COL6A3 Gene-Disease associations (from GenCC):
  • Bethlem myopathy 1A
    Inheritance: AD, AR, SD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Ambry Genetics
  • collagen 6-related myopathy
    Inheritance: AD, AR Classification: DEFINITIVE Submitted by: ClinGen
  • Ullrich congenital muscular dystrophy 1C
    Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
  • dystonia 27
    Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED, NO_KNOWN Submitted by: Illumina, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics, Orphanet
  • Ullrich congenital muscular dystrophy 1A
    Inheritance: AR, AD, SD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
  • Bethlem myopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Ullrich congenital muscular dystrophy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.0553841).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL6A3NM_004369.4 linkc.8804C>A p.Ala2935Glu missense_variant Exon 40 of 44 ENST00000295550.9 NP_004360.2
COL6A3NM_057167.4 linkc.8186C>A p.Ala2729Glu missense_variant Exon 39 of 43 NP_476508.2
COL6A3NM_057166.5 linkc.6983C>A p.Ala2328Glu missense_variant Exon 37 of 41 NP_476507.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL6A3ENST00000295550.9 linkc.8804C>A p.Ala2935Glu missense_variant Exon 40 of 44 1 NM_004369.4 ENSP00000295550.4

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152230
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000797
AC:
2
AN:
250850
AF XY:
0.0000147
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:
0.00
GnomAD4 exome
AF:
0.00000342
AC:
5
AN:
1460778
Hom.:
0
Cov.:
31
AF XY:
0.00000550
AC XY:
4
AN XY:
726702
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33458
American (AMR)
AF:
0.00
AC:
0
AN:
44662
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26116
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39678
South Asian (SAS)
AF:
0.0000580
AC:
5
AN:
86202
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53340
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5758
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111216
Other (OTH)
AF:
0.00
AC:
0
AN:
60348
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152230
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74376
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
ExAC
AF:
0.00000824
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
Jul 19, 2021
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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but 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 COL6A3-related disease. This variant is present in population databases (rs36020669, ExAC 0.006%). This sequence change replaces alanine with glutamic acid at codon 2935 of the COL6A3 protein (p.Ala2935Glu). The alanine residue is weakly conserved and there is a moderate physicochemical difference between alanine and glutamic acid.

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Benign
-0.25
T
BayesDel_noAF
Benign
-0.41
CADD
Benign
5.4
DANN
Benign
0.42
DEOGEN2
Benign
0.0
.;T;.;T;.
Eigen
Benign
-1.5
Eigen_PC
Benign
-1.5
FATHMM_MKL
Benign
0.093
N
LIST_S2
Benign
0.59
T;T;T;T;.
M_CAP
Benign
0.027
D
MetaRNN
Benign
0.055
T;T;T;T;T
MetaSVM
Benign
-0.71
T
MutationAssessor
Benign
0.0
.;M;.;.;.
PhyloP100
-1.0
PrimateAI
Benign
0.31
T
PROVEAN
Benign
-0.47
N;N;N;.;N
REVEL
Benign
0.20
Sift
Benign
0.20
T;T;T;.;T
Sift4G
Benign
0.062
T;T;T;T;T
Vest4
0.099
ClinPred
0.048
T
GERP RS
0.38
Varity_R
0.079
gMVP
0.13
Mutation Taster
=84/16
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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: rs36020669; hg19: chr2-238244939; API