21-45997713-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_001848.3(COL6A1):c.1475C>T(p.Ala492Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000353 in 1,592,966 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A492D) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00029 ( 0 hom., cov: 34)

Exomes 𝑓: 0.00036 ( 3 hom. )

Consequence

COL6A1
NM_001848.3 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: -0.196

Publications

3 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

COL6A1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -20 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.007149756).

BP6

Variant 21-45997713-C-T is Benign according to our data. Variant chr21-45997713-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 340319.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS1

Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.000289 (44/152290) while in subpopulation EAS AF = 0.00813 (42/5166). AF 95% confidence interval is 0.00618. There are 0 homozygotes in GnomAd4. There are 25 alleles in the male GnomAd4 subpopulation. Median coverage is 34. This position passed quality control check.

BS2

High Homozygotes in GnomAdExome4 at 3 AR,AD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL6A1	NM_001848.3 link	c.1475C>T	p.Ala492Val	missense_variant	Exon 22 of 35	ENST00000361866.8	NP_001839.2	P12109A0A384P5H7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL6A1	ENST00000361866.8 link	c.1475C>T	p.Ala492Val	missense_variant	Exon 22 of 35	1	NM_001848.3	ENSP00000355180.3		P12109
COL6A1	ENST00000683550.1 link	n.250C>T		non_coding_transcript_exon_variant	Exon 3 of 5

Frequencies

GnomAD3 genomes

AF:

0.000289

AC:

AN:

152172

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00811

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000594

AC:

127

AN:

213664

AF XY:

0.000493

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00773

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000107

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000360

AC:

519

AN:

1440676

Hom.:

Cov.:

AF XY:

0.000357

AC XY:

255

AN XY:

714772

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33072

American (AMR)

AF:

0.0000237

AC:

AN:

42182

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25698

East Asian (EAS)

AF:

0.0129

AC:

500

AN:

38710

South Asian (SAS)

AF:

0.00

AC:

AN:

83112

European-Finnish (FIN)

AF:

0.00

AC:

AN:

50892

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5700

European-Non Finnish (NFE)

AF:

0.00000272

AC:

AN:

1101764

Other (OTH)

AF:

0.000252

AC:

AN:

59546

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.497

Heterozygous variant carriers

101

134

168

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

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:

0.000289

AC:

AN:

152290

Hom.:

Cov.:

AF XY:

0.000336

AC XY:

AN XY:

74462

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41572

American (AMR)

AF:

0.0000653

AC:

AN:

15312

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00813

AC:

AN:

5166

South Asian (SAS)

AF:

0.000207

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10630

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67986

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.476

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:

0.000276

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000117

AC:

ExAC

AF:

0.000656

AC:

Asia WGS

AF:

0.00231

AC:

AN:

3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:2

Mar 27, 2015

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Jun 27, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: COL6A1 c.1475C>T (p.Ala492Val) results in a non-conservative amino acid change located in the Collagen triple helix repeat region (IPR008160) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 0.00035 in 1586060 control chromosomes, predominantly at a frequency of 0.012 within the East Asian subpopulation in the gnomAD database, including 3 homozygotes. However, the variant was reported in some East Asian subpopulations with an even higher allele frequency, e.g. in the Japanese, with an allele frequency of 0.018, including 26 homozygotes (in the jMorp database; PMID: 33179747). The observed variant frequency within East Asian control individuals in the gnomAD database is higher than the estimated maximal expected allele frequency for a pathogenic variant in COL6A1 causing Ullrich congenital muscular dystrophy 1 phenotype (0.0035). To our knowledge, no occurrence of c.1475C>T in individuals affected with Ullrich congenital muscular dystrophy 1 and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 340319). Based on the evidence outlined above, the variant was classified as benign. -

Collagen 6-related myopathy

Benign:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: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 benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Bethlem myopathy 1A

Benign:1

Oct 07, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.069

BayesDel_addAF

Benign

-0.38

BayesDel_noAF

Benign

-0.31

CADD

Benign

(source)

DANN

Uncertain

0.98

DEOGEN2

Uncertain

0.53

D;T

Eigen

Benign

-0.66

Eigen_PC

Benign

-0.58

FATHMM_MKL

Benign

0.055

LIST_S2

Uncertain

0.91

D;D

MetaRNN

Benign

0.0071

T;T

MetaSVM

Benign

-0.40

MutationAssessor

Benign

0.81

L;.

PhyloP100

-0.20

PrimateAI

Uncertain

0.57

PROVEAN

Benign

-1.2

N;.

REVEL

Benign

0.20

Sift

Benign

0.28

T;.

Sift4G

Benign

0.29

T;T

Polyphen

0.0020

B;.

Vest4

0.28

MVP

0.24

MPC

0.31

ClinPred

0.029

GERP RS

3.4

Varity_R

0.12

gMVP

0.29

Mutation Taster

=97/3

polymorphism

(source)

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

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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