rs144814689

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS1

The NM_001848.3(COL6A1):​c.2876T>C​(p.Val959Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000951 in 1,608,782 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict 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. V959M) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00047 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000056 ( 0 hom. )

Consequence

COL6A1
NM_001848.3 missense

Scores

3
16

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:2

Conservation

PhyloP100: 2.90

Publications

2 publications found
Variant links:
Genes affected
COL6A1 (HGNC:2211): (collagen type VI alpha 1 chain) The collagens are a superfamily of proteins that play a role in maintaining the integrity of various tissues. Collagens are extracellular matrix proteins and have a triple-helical domain as their common structural element. Collagen VI is a major structural component of microfibrils. The basic structural unit of collagen VI is a heterotrimer of the alpha1(VI), alpha2(VI), and alpha3(VI) chains. The alpha2(VI) and alpha3(VI) chains are encoded by the COL6A2 and COL6A3 genes, respectively. The protein encoded by this gene is the alpha 1 subunit of type VI collagen (alpha1(VI) chain). Mutations in the genes that code for the collagen VI subunits result in the autosomal dominant disorder, Bethlem myopathy. [provided by RefSeq, Jul 2008]
COL6A1 Gene-Disease associations (from GenCC):
  • collagen 6-related myopathy
    Inheritance: AD, AR Classification: DEFINITIVE Submitted by: ClinGen
  • Bethlem myopathy 1A
    Inheritance: AR, AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P
  • Ullrich congenital muscular dystrophy 1A
    Inheritance: AD, AR Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
  • 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: Benign. The variant received -9 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.020249516).
BP6
Variant 21-46003802-T-C is Benign according to our data. Variant chr21-46003802-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 452704.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000466 (71/152276) while in subpopulation AFR AF = 0.00161 (67/41556). AF 95% confidence interval is 0.0013. There are 0 homozygotes in GnomAd4. There are 30 alleles in the male GnomAd4 subpopulation. Median coverage is 34. This position passed quality control check.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL6A1NM_001848.3 linkc.2876T>C p.Val959Ala missense_variant Exon 35 of 35 ENST00000361866.8 NP_001839.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL6A1ENST00000361866.8 linkc.2876T>C p.Val959Ala missense_variant Exon 35 of 35 1 NM_001848.3 ENSP00000355180.3

Frequencies

GnomAD3 genomes
AF:
0.000467
AC:
71
AN:
152158
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.00162
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.000478
GnomAD2 exomes
AF:
0.000182
AC:
45
AN:
247208
AF XY:
0.000119
show subpopulations
Gnomad AFR exome
AF:
0.00222
Gnomad AMR exome
AF:
0.000203
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000180
Gnomad OTH exome
AF:
0.000165
GnomAD4 exome
AF:
0.0000563
AC:
82
AN:
1456506
Hom.:
0
Cov.:
34
AF XY:
0.0000539
AC XY:
39
AN XY:
723670
show subpopulations
African (AFR)
AF:
0.00162
AC:
54
AN:
33358
American (AMR)
AF:
0.000202
AC:
9
AN:
44604
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26066
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39592
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86200
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52216
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5756
European-Non Finnish (NFE)
AF:
0.00000361
AC:
4
AN:
1108536
Other (OTH)
AF:
0.000249
AC:
15
AN:
60178
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
6
13
19
26
32
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:
0.000466
AC:
71
AN:
152276
Hom.:
0
Cov.:
34
AF XY:
0.000403
AC XY:
30
AN XY:
74462
show subpopulations
African (AFR)
AF:
0.00161
AC:
67
AN:
41556
American (AMR)
AF:
0.000131
AC:
2
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5156
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
Other (OTH)
AF:
0.000473
AC:
1
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.503
Heterozygous variant carriers
0
4
8
13
17
21
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:
0.000601
Hom.:
0
Bravo
AF:
0.000805
ESP6500AA
AF:
0.00113
AC:
5
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.000165
AC:
20

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:4Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:3
Jan 10, 2022
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 28, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Identified in a patient with limb girdle muscular dystrophy (Nallamilli et al., 2018); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 30564623) -

Oct 27, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Bethlem myopathy 1A Uncertain:1Benign:1
Nov 02, 2023
Zotz-Klimas Genetics Lab, MVZ Zotz Klimas
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jan 23, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Benign:1
Nov 04, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: COL6A1 c.2876T>C (p.Val959Ala) results in a non-conservative amino acid change located in the Overlapping homologous superfamilies domain (IPR002035) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00018 in 247208 control chromosomes, predominantly at a frequency of 0.0022 within the African or African-American subpopulation in the gnomAD database. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 4631 fold of the estimated maximal expected allele frequency for a pathogenic variant in COL6A1 causing Collagen Type VI-Related Disorders phenotype (4.8e-07), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. c.2876T>C has been reported in the literature in at-least one individual reported with a clinical suspicion for LGMD, however authors classified the variant as VUS (Nallamilli_2018). This report does not provide unequivocal conclusions about association of the variant with Collagen Type VI-Related Disorders. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as VUS (n=2) and likely benign (n=1). Based on the evidence outlined above, the variant was classified as likely benign. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.17
BayesDel_addAF
Benign
-0.26
T
BayesDel_noAF
Benign
-0.15
CADD
Benign
21
DANN
Benign
0.96
DEOGEN2
Benign
0.33
T;T
Eigen
Benign
-0.066
Eigen_PC
Benign
0.014
FATHMM_MKL
Uncertain
0.91
D
LIST_S2
Benign
0.66
T;T
M_CAP
Benign
0.066
D
MetaRNN
Benign
0.020
T;T
MetaSVM
Benign
-0.80
T
MutationAssessor
Benign
0.44
N;.
PhyloP100
2.9
PrimateAI
Uncertain
0.73
T
PROVEAN
Benign
-2.3
N;.
REVEL
Uncertain
0.37
Sift
Benign
0.13
T;.
Sift4G
Benign
0.22
T;T
Polyphen
0.91
P;.
Vest4
0.33
MVP
0.62
MPC
0.38
ClinPred
0.034
T
GERP RS
4.8
Varity_R
0.18
gMVP
0.36
Mutation Taster
=37/63
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: rs144814689; hg19: chr21-47423716; COSMIC: COSV107450220; COSMIC: COSV107450220; API