rs202185764

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

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

The NM_004369.4(COL6A3):c.2972C>T(p.Ala991Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000133 in 1,614,068 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/22 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. A991E) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00014 ( 1 hom. )

Consequence

COL6A3
NM_004369.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.591

Publications

2 publications found

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]

COL6A3 Gene-Disease associations (from GenCC):

Bethlem myopathy 1A
Inheritance: AD, AR, SD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Ambry Genetics
collagen 6-related myopathy
Inheritance: AD, AR Classification: DEFINITIVE Submitted by: ClinGen
Ullrich congenital muscular dystrophy 1C
Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
dystonia 27
Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED, NO_KNOWN Submitted by: Illumina, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics, Orphanet
Ullrich congenital muscular dystrophy 1A
Inheritance: AR, AD, SD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
Bethlem myopathy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Ullrich congenital muscular dystrophy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

COL6A3 links:

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=0.042110503).

BP6

Variant 2-237376870-G-A is Benign according to our data. Variant chr2-237376870-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 476515.

BS1

Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.000142 (207/1461894) while in subpopulation MID AF = 0.00121 (7/5768). AF 95% confidence interval is 0.00068. There are 1 homozygotes in GnomAdExome4. There are 134 alleles in the male GnomAdExome4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL6A3	NM_004369.4 link	c.2972C>T	p.Ala991Val	missense_variant	Exon 7 of 44	ENST00000295550.9	NP_004360.2	P12111-1D9ZGF2Q8N4Z1Q63HQ4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL6A3	ENST00000295550.9 link	c.2972C>T	p.Ala991Val	missense_variant	Exon 7 of 44	1	NM_004369.4	ENSP00000295550.4		P12111-1

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152174

Hom.:

Cov.:

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:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000882

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000159

AC:

AN:

251494

AF XY:

0.000191

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000114

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000142

AC:

207

AN:

1461894

Hom.:

Cov.:

AF XY:

0.000184

AC XY:

134

AN XY:

727248

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000447

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.000835

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00121

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000102

AC:

113

AN:

1112012

Other (OTH)

AF:

0.000199

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.483

Heterozygous variant carriers

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:

0.0000526

AC:

AN:

152174

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74340

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41454

American (AMR)

AF:

0.00

AC:

AN:

15272

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.000207

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10604

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000882

AC:

AN:

68036

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

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:

0.0000521

Hom.:

Bravo

AF:

0.0000869

ExAC

AF:

0.000173

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Aug 02, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.2972C>T (p.A991V) alteration is located in exon 7 (coding exon 6) of the COL6A3 gene. This alteration results from a C to T substitution at nucleotide position 2972, causing the alanine (A) at amino acid position 991 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Tip-toe gait

Uncertain:1

Nov 25, 2020

Practice for Gait Abnormalities, David Pomarino, Competency Network Toe Walking c/o Practice Pomarino

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

We conducted a clinical examination of patients about toe walking. The COL6A3:c.2972C>T was detected in 1 patient. This variant has not yet been reported in the HGMD and LOVD databases or in the literature. However, it is classified in the ClinVar database as likely benigne in relation to Bethlem myopathy (1 entry). Different in-silico prediction programs [MutationTaster, PolyPhen-2, MutationAssessor] do not assign functional significance to the variant. Influence on altered splicing of mRNA could also not be determined [MutationTaster, varSEAK]. Based on the available data, this variant is classified as VUS. 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. -

Bethlem myopathy 1A

Benign:1

Dec 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Benign:1

Mar 21, 2023

Revvity Omics, Revvity

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

0.11

BayesDel_addAF

Benign

-0.39

BayesDel_noAF

Benign

-0.42

CADD

Benign

(source)

DANN

Uncertain

0.97

DEOGEN2

Benign

0.24

.;T;.;T;.;.;.

Eigen

Benign

-0.74

Eigen_PC

Benign

-0.79

FATHMM_MKL

Benign

0.19

LIST_S2

Benign

0.83

T;T;T;T;.;T;T

M_CAP

Benign

0.0078

MetaRNN

Benign

0.042

T;T;T;T;T;T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

0.69

.;N;.;.;.;.;.

PhyloP100

0.59

PrimateAI

Benign

0.35

PROVEAN

Benign

-1.6

N;N;N;.;N;N;N

REVEL

Benign

0.095

Sift

Benign

0.14

T;T;T;.;T;T;T

Sift4G

Benign

0.19

T;T;T;T;T;T;T

Polyphen

0.53

P;B;.;.;P;.;.

Vest4

0.079

MutPred

0.50

.;Gain of helix (P = 0.0696);.;.;.;.;.;

MVP

0.42

MPC

0.18

ClinPred

0.014

GERP RS

1.3

Varity_R

0.033

gMVP

0.58

Mutation Taster

=94/6

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