21-46114031-A-G

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_StrongBP6BP7

The NM_001849.4(COL6A2):​c.759A>G​(p.Glu253Glu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000149 in 1,613,844 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).

Frequency

Genomes: 𝑓 0.00020 ( 0 hom., cov: 31)
Exomes 𝑓: 0.00014 ( 0 hom. )

Consequence

COL6A2
NM_001849.4 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1B:7

Conservation

PhyloP100: 2.84

Publications

0 publications found
Variant links:
Genes affected
COL6A2 (HGNC:2212): (collagen type VI alpha 2 chain) This gene encodes one of the three alpha chains of type VI collagen, a beaded filament collagen found in most connective tissues. The product of this gene contains several domains similar to von Willebrand Factor type A domains. 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 this gene are associated with Bethlem myopathy and Ullrich scleroatonic muscular dystrophy. Three transcript variants have been identified for this gene. [provided by RefSeq, Jul 2008]
COL6A2 Gene-Disease associations (from GenCC):
  • collagen 6-related myopathy
    Inheritance: AD, AR Classification: DEFINITIVE Submitted by: ClinGen
  • Ullrich congenital muscular dystrophy 1B
    Inheritance: AR, AD Classification: DEFINITIVE Submitted by: G2P
  • Bethlem myopathy 1A
    Inheritance: AD, AR Classification: STRONG Submitted by: Genomics England PanelApp
  • Ullrich congenital muscular dystrophy 1A
    Inheritance: AD, AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • Bethlem myopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Ullrich congenital muscular dystrophy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • myosclerosis
    Inheritance: AR 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 -6 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.56).
BP6
Variant 21-46114031-A-G is Benign according to our data. Variant chr21-46114031-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 93960.
BP7
Synonymous conserved (PhyloP=2.84 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001849.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL6A2
NM_001849.4
MANE Select
c.759A>Gp.Glu253Glu
synonymous
Exon 5 of 28NP_001840.3
COL6A2
NM_058174.3
MANE Plus Clinical
c.759A>Gp.Glu253Glu
synonymous
Exon 5 of 28NP_478054.2
COL6A2
NM_058175.3
c.759A>Gp.Glu253Glu
synonymous
Exon 5 of 28NP_478055.2

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL6A2
ENST00000300527.9
TSL:1 MANE Select
c.759A>Gp.Glu253Glu
synonymous
Exon 5 of 28ENSP00000300527.4
COL6A2
ENST00000397763.6
TSL:5 MANE Plus Clinical
c.759A>Gp.Glu253Glu
synonymous
Exon 5 of 28ENSP00000380870.1
COL6A2
ENST00000409416.6
TSL:5
c.759A>Gp.Glu253Glu
synonymous
Exon 4 of 27ENSP00000387115.1

Frequencies

GnomAD3 genomes
AF:
0.000197
AC:
30
AN:
152140
Hom.:
0
Cov.:
31
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:
0.0000941
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000412
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000119
AC:
30
AN:
251284
AF XY:
0.000110
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000867
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000924
Gnomad NFE exome
AF:
0.000220
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000144
AC:
210
AN:
1461586
Hom.:
0
Cov.:
30
AF XY:
0.000154
AC XY:
112
AN XY:
727114
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000671
AC:
3
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.0000941
AC:
5
AN:
53156
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000177
AC:
197
AN:
1111978
Other (OTH)
AF:
0.0000662
AC:
4
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.473
Heterozygous variant carriers
0
13
25
38
50
63
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.000197
AC:
30
AN:
152258
Hom.:
0
Cov.:
31
AF XY:
0.000134
AC XY:
10
AN XY:
74444
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41550
American (AMR)
AF:
0.00
AC:
0
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.0000941
AC:
1
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000412
AC:
28
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
2
3
5
6
8
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:
0.000267
Hom.:
0
Bravo
AF:
0.000166
EpiCase
AF:
0.000327
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:1Benign:7
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:2
Feb 16, 2016
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Apr 03, 2018
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Nov 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

COL6A2: BP4, BP7

Tip-toe gait Pathogenic:1
Practice for Gait Abnormalities, David Pomarino, Competency Network Toe Walking c/o Practice Pomarino
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

Myopathy refers to diseases that affect skeletal Muscles. These diseases attack muscle fibers, making muscles weak. Inherited myopathies are often caused by inheriting an abnormal gene mutation from a parent that causes the disease. Symptoms of congenital myopathies usually start at birth or in early childhood, but may not appear until the teen years or even later in adulthood. Congenital myopathies are somewhat unique compared with other inherited myopathies, as weakness typically affects all muscles and is often not progressive. Symptoms are: Muscle weakness, most commonly of upper arms and shoulders and thighs, muscle cramps, stiffness and spasms, fatigue with exertion and lack of energy. Our patients all walk on tiptoe, so they show similar symptoms. When we genetically test them with our toe walking panel, we find that around 90 per cent of them have a genetic variant that explains their toe walking. These can be assigned, for example, to the area of myopathies (such as variants of the COL6A3 gene), the area of hereditary neuropathies (such as variants of the KMT2C gene) or the area of metabolic diseases (such as variants of the PYGM gene). In a smaller group of patients with almost identical symptoms, no abnormality is found in the genes of our panel, but spastic paraplegia can be detected. In another small group of our toe walkers, no abnormalities can be detected in the genes analysed in our toe walking panel, nor do they suffer from spastic paraplegia, as is also the case with healthy children. In contrast to these, however, they show a tiptoe gait. These patients suffer from infantile cerebral palsy, in which toe walking can also be observed.

not specified Benign:1
Feb 16, 2025
Laboratory of Genetics, Children's Clinical University Hospital Latvia
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Myosclerosis Benign:1
Jun 14, 2016
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Collagen 6-related myopathy Benign:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease.

Bethlem myopathy 1A Benign:1
Jan 25, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

COL6A2-related disorder Benign:1
Jan 22, 2022
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications).

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.56
CADD
Benign
9.2
DANN
Benign
0.58
PhyloP100
2.8
Mutation Taster
=100/0
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
Splicevardb
1.0
SpliceAI score (max)
0.010
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: rs140404854; hg19: chr21-47533945; API