NM_004369.4:c.973G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PP3_Strong

The NM_004369.4(COL6A3):​c.973G>A​(p.Ala325Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000743 in 1,614,022 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A325V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

COL6A3
NM_004369.4 missense

Scores

12
5
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 7.84

Publications

7 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 4 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.981

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004369.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL6A3
NM_004369.4
MANE Select
c.973G>Ap.Ala325Thr
missense
Exon 4 of 44NP_004360.2
COL6A3
NM_057167.4
c.355G>Ap.Ala119Thr
missense
Exon 3 of 43NP_476508.2
COL6A3
NM_057165.5
c.355G>Ap.Ala119Thr
missense
Exon 3 of 8NP_476506.3

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL6A3
ENST00000295550.9
TSL:1 MANE Select
c.973G>Ap.Ala325Thr
missense
Exon 4 of 44ENSP00000295550.4
COL6A3
ENST00000392004.7
TSL:1
c.355G>Ap.Ala119Thr
missense
Exon 3 of 8ENSP00000375861.3
COL6A3
ENST00000433762.1
TSL:1
c.973G>Ap.Ala325Thr
missense
Exon 4 of 6ENSP00000389539.1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152186
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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
GnomAD4 exome
AF:
0.00000616
AC:
9
AN:
1461836
Hom.:
0
Cov.:
32
AF XY:
0.00000963
AC XY:
7
AN XY:
727210
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86254
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1111974
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000197
AC:
3
AN:
152186
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74340
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41450
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:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.408
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:
0.00
Hom.:
0
Bravo
AF:
0.0000264

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Oct 10, 2016
Genetic Services Laboratory, University of Chicago
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Bethlem myopathy 1A Uncertain:1
Jul 30, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 325 of the COL6A3 protein (p.Ala325Thr). This variant has not been reported in the literature in individuals affected with COL6A3-related conditions. 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. 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 COL6A3 protein function. ClinVar contains an entry for this variant (Variation ID: 434817).

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.66
BayesDel_addAF
Pathogenic
0.55
D
BayesDel_noAF
Pathogenic
0.55
CADD
Uncertain
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.47
T
Eigen
Pathogenic
0.89
Eigen_PC
Pathogenic
0.77
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.90
D
M_CAP
Pathogenic
0.95
D
MetaRNN
Pathogenic
0.98
D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.9
H
PhyloP100
7.8
PrimateAI
Uncertain
0.64
T
PROVEAN
Benign
-1.8
N
REVEL
Pathogenic
0.85
Sift
Uncertain
0.0050
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.76
MutPred
0.85
Gain of helix (P = 0.1736)
MVP
0.98
MPC
0.63
ClinPred
0.96
D
GERP RS
5.2
Varity_R
0.20
gMVP
0.70
Mutation Taster
=33/67
disease causing

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: rs905662421; hg19: chr2-238296564; COSMIC: COSV55087815; API