rs113360085

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2BP4BP6BS1

The NM_004369.4(COL6A3):​c.3445C>T​(p.Arg1149Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000354 in 1,614,102 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1149Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00036 ( 0 hom. )

Consequence

COL6A3
NM_004369.4 missense

Scores

2
10
7

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:2

Conservation

PhyloP100: -0.746
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.41057393).
BP6
Variant 2-237374646-G-A is Benign according to our data. Variant chr2-237374646-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 284774.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=5}.
BS1
Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.000263 (40/152248) while in subpopulation NFE AF= 0.000515 (35/67996). AF 95% confidence interval is 0.000379. There are 0 homozygotes in gnomad4. There are 17 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL6A3NM_004369.4 linkc.3445C>T p.Arg1149Trp missense_variant Exon 8 of 44 ENST00000295550.9 NP_004360.2 P12111-1D9ZGF2Q8N4Z1Q63HQ4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL6A3ENST00000295550.9 linkc.3445C>T p.Arg1149Trp missense_variant Exon 8 of 44 1 NM_004369.4 ENSP00000295550.4 P12111-1

Frequencies

GnomAD3 genomes
AF:
0.000263
AC:
40
AN:
152130
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000482
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000196
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:
0.000515
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000187
AC:
47
AN:
251266
Hom.:
0
AF XY:
0.000177
AC XY:
24
AN XY:
135844
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000318
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000317
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000364
AC:
532
AN:
1461854
Hom.:
0
Cov.:
32
AF XY:
0.000370
AC XY:
269
AN XY:
727232
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.000380
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000232
Gnomad4 FIN exome
AF:
0.0000375
Gnomad4 NFE exome
AF:
0.000433
Gnomad4 OTH exome
AF:
0.000497
GnomAD4 genome
AF:
0.000263
AC:
40
AN:
152248
Hom.:
0
Cov.:
32
AF XY:
0.000228
AC XY:
17
AN XY:
74442
show subpopulations
Gnomad4 AFR
AF:
0.0000481
Gnomad4 AMR
AF:
0.000196
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000515
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000410
Hom.:
1
Bravo
AF:
0.000302
TwinsUK
AF:
0.000539
AC:
2
ALSPAC
AF:
0.000778
AC:
3
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000349
AC:
3
ExAC
AF:
0.000132
AC:
16
Asia WGS
AF:
0.000577
AC:
2
AN:
3478
EpiCase
AF:
0.000436
EpiControl
AF:
0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:6Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:5
Jul 17, 2018
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Aug 12, 2022
Revvity Omics, Revvity
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

May 16, 2017
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

A variant of uncertain significance has been identified in the COL6A3 gene. The R1149W variant has been reported previously in an individual with a clinical diagnosis of limb-girdle muscular dystrophy who also had a second COL6A3 variant identified; however, parental studies were not reported, and this patient also had two variants identified in the NEB gene (Savarese et al., 2014). The R1149W variant is observed in 2/10,366 (0.02%) alleles from individuals of African background (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The R1149W variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. However, this substitution occurs at a position that is not conserved. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Mar 22, 2024
Mayo Clinic Laboratories, Mayo Clinic
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

-
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

The COL6A3 p.Arg542Trp variant was not identified in the literature but was identified in dbSNP (ID: rs113360085) and ClinVar (classified as uncertain significance by EGL Genetic Diagnostics, GeneDx, and Invitae, and as likely benign by Illumina). The variant was identified in control databases in 56 of 282644 chromosomes at a frequency of 0.0001981 (Genome Aggregation Database March 6, 2019, v2.1.1). The variant was observed in the following populations: European (non-Finnish) in 45 of 129010 chromosomes (freq: 0.000349) and Latino in 11 of 35436 chromosomes (freq: 0.00031), but was not observed in the African, Ashkenazi Jewish, East Asian, European (Finnish), Other, or South Asian populations. The p.Arg542 residue is not conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -

not specified Uncertain:1
Dec 02, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: COL6A3 c.3445C>T (p.Arg1149Trp) results in a non-conservative amino acid change located in the von Willebrand factor (vWF) type A domain (IPR002035) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00019 in 251266 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in COL6A3 causing Ullrich congenital muscular dystrophy 1-AR (0.00019 vs 0.0035), allowing no conclusion about variant significance. c.3445C>T has been reported in the literature in at least one compound heterozygous individual affected with Limb-girdle muscular dystrophy carrying a second variant classified as benign in the presence of additional variants in the NEB gene (e.g. Savarese_2014). This report does not provide unequivocal conclusions about association of the variant with Ullrich congenital muscular dystrophy 1-AR. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 25214167). ClinVar contains an entry for this variant (Variation ID: 284774). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Collagen 6-related myopathy Benign:1
Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to determine this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

Bethlem myopathy 1A Benign:1
Dec 27, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Uncertain
0.033
T
BayesDel_noAF
Pathogenic
0.14
CADD
Benign
14
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.49
.;T;.;T;.;.;.
Eigen
Benign
-0.61
Eigen_PC
Benign
-0.88
FATHMM_MKL
Benign
0.19
N
LIST_S2
Uncertain
0.97
D;D;D;D;.;D;D
M_CAP
Uncertain
0.17
D
MetaRNN
Benign
0.41
T;T;T;T;T;T;T
MetaSVM
Uncertain
0.043
D
MutationAssessor
Pathogenic
3.1
.;M;.;.;.;.;.
PrimateAI
Benign
0.37
T
PROVEAN
Uncertain
-3.4
D;D;D;.;D;D;D
REVEL
Uncertain
0.56
Sift
Uncertain
0.0030
D;D;T;.;D;D;D
Sift4G
Uncertain
0.0020
D;D;D;D;D;D;D
Polyphen
1.0
D;D;.;.;D;.;.
Vest4
0.47
MVP
0.87
MPC
0.65
ClinPred
0.29
T
GERP RS
-5.2
Varity_R
0.20
gMVP
0.83

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs113360085; hg19: chr2-238283289; API