rs34741387

Positions:

chr2-237381199-G-A

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_004369.4(COL6A3):c.1613C>T(p.Thr538Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00144 in 1,614,246 control chromosomes in the GnomAD database, including 31 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. T538T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0076 ( 19 hom., cov: 33)

Exomes 𝑓: 0.00080 ( 12 hom. )

Consequence

COL6A3
NM_004369.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1B:3

Conservation

PhyloP100: 1.58

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -13 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0074792504).

BP6

Variant 2-237381199-G-A is Benign according to our data. Variant chr2-237381199-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 128816.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Benign=2}.

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00763 (1162/152358) while in subpopulation AFR AF= 0.0269 (1117/41582). AF 95% confidence interval is 0.0256. There are 19 homozygotes in gnomad4. There are 553 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 19 SD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL6A3	NM_004369.4 linkuse as main transcript	c.1613C>T	p.Thr538Met	missense_variant	5/44	ENST00000295550.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL6A3	ENST00000295550.9 linkuse as main transcript	c.1613C>T	p.Thr538Met	missense_variant	5/44	1	NM_004369.4	P1	P12111-1

Frequencies

GnomAD3 genomes

AF:

0.00762

AC:

1160

AN:

152240

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0269

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00222

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:

0.0000294

Gnomad OTH

AF:

0.00382

GnomAD3 exomes

AF:

0.00201

AC:

506

AN:

251242

Hom.:

AF XY:

0.00157

AC XY:

213

AN XY:

135834

show subpopulations

Gnomad AFR exome

AF:

0.0273

Gnomad AMR exome

AF:

0.00145

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000528

Gnomad OTH exome

AF:

0.000978

GnomAD4 exome

AF:

0.000799

AC:

1168

AN:

1461888

Hom.:

Cov.:

AF XY:

0.000696

AC XY:

506

AN XY:

727246

show subpopulations

Gnomad4 AFR exome

AF:

0.0284

Gnomad4 AMR exome

AF:

0.00150

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000756

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000333

Gnomad4 OTH exome

AF:

0.00166

GnomAD4 genome

AF:

0.00763

AC:

1162

AN:

152358

Hom.:

Cov.:

AF XY:

0.00742

AC XY:

553

AN XY:

74500

show subpopulations

Gnomad4 AFR

AF:

0.0269

Gnomad4 AMR

AF:

0.00222

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00426

Alfa

AF:

0.00138

Hom.:

Bravo

AF:

0.00872

ESP6500AA

AF:

0.0261

AC:

115

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00249

AC:

302

Asia WGS

AF:

0.000866

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:1Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Tip-toe gait

Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

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

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 provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Jan 21, 2014

- -

not specified

Benign:1

Benign, criteria provided, single submitter

clinical testing

GeneDx

Jan 18, 2018

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. -

Bethlem myopathy 1A

Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 29, 2024

- -

COL6A3-related disorder

Benign:1

Benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

May 20, 2020

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

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.099

BayesDel_addAF

Benign

-0.29

BayesDel_noAF

Benign

-0.16

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.72

.;D;.;T;.;.;.;T

Eigen

Benign

0.17

Eigen_PC

Benign

-0.019

FATHMM_MKL

Benign

0.35

LIST_S2

Benign

0.81

T;T;D;D;.;T;T;T

MetaRNN

Benign

0.0075

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

MetaSVM

Uncertain

-0.26

MutationAssessor

Pathogenic

3.3

.;M;.;.;.;.;.;.

MutationTaster

Benign

0.98

N;N;N;N;N;N;N;N

PrimateAI

Benign

0.32

PROVEAN

Uncertain

-3.1

D;D;N;N;D;D;D;D

REVEL

Uncertain

0.32

Sift

Uncertain

0.0030

D;D;D;D;D;D;D;D

Sift4G

Pathogenic

0.0

D;D;D;D;D;D;D;D

Polyphen

1.0

D;D;.;.;D;.;.;.

Vest4

0.46

MVP

0.87

MPC

0.65

ClinPred

0.045

GERP RS

3.6

Varity_R

0.33

gMVP

0.53

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over