chr21-46118635-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM1PP3_ModerateBP6

The NM_001849.4(COL6A2):c.1138C>T(p.Arg380Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000143 in 1,612,530 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R380H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 34)

Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

COL6A2
NM_001849.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 2.55

Publications

5 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

COL6A2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 8 uncertain in NM_001849.4

PP3

MetaRNN computational evidence supports a deleterious effect, 0.906

BP6

Variant 21-46118635-C-T is Benign according to our data. Variant chr21-46118635-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 542974.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL6A2	NM_001849.4 link	c.1138C>T	p.Arg380Cys	missense_variant	Exon 13 of 28	ENST00000300527.9	NP_001840.3	P12110-1A0A384MDP3
COL6A2	NM_058174.3 link	c.1138C>T	p.Arg380Cys	missense_variant	Exon 13 of 28		NP_478054.2	P12110-2
COL6A2	NM_058175.3 link	c.1138C>T	p.Arg380Cys	missense_variant	Exon 13 of 28		NP_478055.2	P12110-3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
COL6A2	ENST00000300527.9 link	c.1138C>T	p.Arg380Cys	missense_variant	Exon 13 of 28	1	NM_001849.4	ENSP00000300527.4	P12110-1
COL6A2	ENST00000397763.6 link	c.1138C>T	p.Arg380Cys	missense_variant	Exon 13 of 28	5		ENSP00000380870.1	P12110-2
COL6A2	ENST00000409416.6 link	c.1138C>T	p.Arg380Cys	missense_variant	Exon 12 of 27	5		ENSP00000387115.1	P12110-3

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152232

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000145

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000162

AC:

AN:

247530

AF XY:

0.0000223

show subpopulations

Gnomad AFR exome

AF:

0.000127

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000898

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000110

AC:

AN:

1460180

Hom.:

Cov.:

AF XY:

0.00000964

AC XY:

AN XY:

726362

show subpopulations

African (AFR)

AF:

0.000119

AC:

AN:

33478

American (AMR)

AF:

0.0000224

AC:

AN:

44698

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26102

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39690

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86130

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52148

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000630

AC:

AN:

1111830

Other (OTH)

AF:

0.0000331

AC:

AN:

60336

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.459

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000459

AC:

AN:

152350

Hom.:

Cov.:

AF XY:

0.0000537

AC XY:

AN XY:

74502

show subpopulations

African (AFR)

AF:

0.000144

AC:

AN:

41588

American (AMR)

AF:

0.00

AC:

AN:

15312

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.000193

AC:

AN:

5176

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68024

Other (OTH)

AF:

0.00

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.518

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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.:

Bravo

AF:

0.0000453

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000248

AC:

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Oct 24, 2019

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Reported previously in a patient with leg weakness and atrophy with sparing of the quadriceps, bilateral foot drop, scapular winging, hand weakness and atrophy, abnormal EMG, and severe contractures. However, this patient and his affected brother were also found to be compound heterozygous for two variants in the GNE gene, and authors concluded their clinical presentation was consistent with GNE myopathy (Dotti et al., 2018); This variant is associated with the following publications: (PMID: 29406958) -

Bethlem myopathy 1A

Benign:1

Dec 06, 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

Uncertain

0.56

BayesDel_addAF

Uncertain

0.035

BayesDel_noAF

Uncertain

0.050

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.67

D;.;.;.

Eigen

Uncertain

0.64

Eigen_PC

Uncertain

0.60

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.89

D;D;.;D

M_CAP

Pathogenic

0.76

MetaRNN

Pathogenic

0.91

D;D;D;D

MetaSVM

Pathogenic

0.91

MutationAssessor

Uncertain

2.6

M;M;M;M

PhyloP100

2.5

PrimateAI

Uncertain

0.70

PROVEAN

Uncertain

-3.9

D;D;D;D

REVEL

Pathogenic

0.77

Sift

Uncertain

0.0030

D;D;D;D

Sift4G

Uncertain

0.013

D;D;D;D

Polyphen

1.0

D;D;D;D

Vest4

0.71

MVP

0.93

MPC

0.71

ClinPred

0.90

GERP RS

4.7

Varity_R

0.42

gMVP

0.56

Mutation Taster

=38/62

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over