2-237365784-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2BP4

The NM_004369.4(COL6A3):​c.5752C>A​(p.Arg1918Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,198 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 variant affecting the same amino acid position, but resulting in a different missense (i.e. R1918H) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

COL6A3
NM_004369.4 missense

Scores

3
16

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.17

Publications

2 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: Uncertain_significance. The variant received 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.2932651).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL6A3NM_004369.4 linkc.5752C>A p.Arg1918Ser missense_variant Exon 12 of 44 ENST00000295550.9 NP_004360.2
COL6A3NM_057167.4 linkc.5134C>A p.Arg1712Ser missense_variant Exon 11 of 43 NP_476508.2
COL6A3NM_057166.5 linkc.3931C>A p.Arg1311Ser missense_variant Exon 9 of 41 NP_476507.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL6A3ENST00000295550.9 linkc.5752C>A p.Arg1918Ser missense_variant Exon 12 of 44 1 NM_004369.4 ENSP00000295550.4
COL6A3ENST00000472056.5 linkc.3931C>A p.Arg1311Ser missense_variant Exon 9 of 41 1 ENSP00000418285.1
COL6A3ENST00000353578.9 linkc.5134C>A p.Arg1712Ser missense_variant Exon 11 of 43 5 ENSP00000315873.4

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152198
Hom.:
0
Cov.:
32
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
GnomAD4 exome
Cov.:
32
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152198
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74356
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

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

Submissions by phenotype

Bethlem myopathy 1A Uncertain:1
Feb 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with serine, which is neutral and polar, at codon 1918 of the COL6A3 protein (p.Arg1918Ser). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with COL6A3-related conditions. ClinVar contains an entry for this variant (Variation ID: 476538). 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 not expected to disrupt COL6A3 protein function with a negative predictive value of 80%. 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
Benign
0.34
BayesDel_addAF
Uncertain
0.029
T
BayesDel_noAF
Benign
-0.20
CADD
Uncertain
24
DANN
Benign
0.97
DEOGEN2
Benign
0.19
.;T;.;T;.
Eigen
Benign
-0.0033
Eigen_PC
Benign
0.12
FATHMM_MKL
Uncertain
0.87
D
LIST_S2
Benign
0.83
T;T;T;T;.
M_CAP
Benign
0.0098
T
MetaRNN
Benign
0.29
T;T;T;T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
2.0
.;M;.;.;.
PhyloP100
1.2
PrimateAI
Uncertain
0.51
T
PROVEAN
Benign
-1.7
N;N;N;.;N
REVEL
Benign
0.13
Sift
Benign
0.067
T;T;T;.;T
Sift4G
Benign
0.12
T;T;T;T;T
Polyphen
0.56
P;B;.;.;P
Vest4
0.47
MutPred
0.38
.;Gain of phosphorylation at R1918 (P = 0.0797);.;.;.;
MVP
0.63
MPC
0.19
ClinPred
0.52
D
GERP RS
4.4
Varity_R
0.14
gMVP
0.76
Mutation Taster
=60/40
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: rs750367811; hg19: chr2-238274427; API