rs190667494

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_004369.4(COL6A3):c.8966-3C>A variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000378 in 1,614,060 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00024 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

COL6A3
NM_004369.4 splice_region, splice_polypyrimidine_tract, intron

Scores

Splicing: ADA: 0.8042

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 1.56

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 Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.77).

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	MANE
COL6A3	NM_004369.4 linkuse as main transcript	c.8966-3C>A	splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant	ENST00000295550.9
COL6A3	NM_057166.5 linkuse as main transcript	c.7145-3C>A	splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant
COL6A3	NM_057167.4 linkuse as main transcript	c.8348-3C>A	splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL6A3	ENST00000295550.9 linkuse as main transcript	c.8966-3C>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_004369.4	P1	P12111-1

Frequencies

GnomAD3 genomes

AF:

0.000243

AC:

AN:

152150

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000797

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000262

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000479

AC:

AN:

250454

Hom.:

AF XY:

0.0000517

AC XY:

AN XY:

135442

show subpopulations

Gnomad AFR exome

AF:

0.000739

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000164

AC:

AN:

1461792

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

727202

show subpopulations

Gnomad4 AFR exome

AF:

0.000597

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.000243

AC:

AN:

152268

Hom.:

Cov.:

AF XY:

0.000175

AC XY:

AN XY:

74480

show subpopulations

Gnomad4 AFR

AF:

0.000794

Gnomad4 AMR

AF:

0.000261

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000113

Hom.:

Bravo

AF:

0.000208

Asia WGS

AF:

0.000577

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jan 30, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Nov 03, 2015	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Mar 17, 2021	In silico analysis supports a deleterious effect on splicing; Has not been previously published as pathogenic or benign to our knowledge -

Bethlem myopathy 1A

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 21, 2023

This sequence change falls in intron 40 of the COL6A3 gene. It does not directly change the encoded amino acid sequence of the COL6A3 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs190667494, gnomAD 0.08%). This variant has not been reported in the literature in individuals affected with COL6A3-related conditions. ClinVar contains an entry for this variant (Variation ID: 284126). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Ullrich congenital muscular dystrophy 1A

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

May 07, 2021

0103 - Dominant negative and loss of function are known mechanisms of disease in this gene. A dominant negative mechanism has been shown to result from missense variants affecting a glycine residue within a Gly-X-Y triple helical repeat, while loss of function is associated with recessive disease due to other missense and protein-truncating variants (OMIM, PMID: 20301676). (I) 0108 - This gene is associated with both recessive and dominant disease. This gene is associated with autosomal recessive dystonia 27 (MIM#616411) and autosomal recessive and dominant Bethlem myopathy 1 (MIM#158810) and Ullrich congenital muscular dystrophy 1 (MIM#254090). (I) 0212 - Non-canonical splice site variant without proven consequence on splicing (no functional evidence available). (SP) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v3) <0.01 for a recessive condition (37 heterozygotes, 0 homozygotes). (SP) 0508 - In silico predictions for abnormal splicing are conflicting. (I) 0705 - No comparable non-canonical splice site variants have previous evidence for pathogenicity. (I) 0809 - Previous evidence of pathogenicity for this variant is inconclusive. It has been reported as uncertain significance in ClinVar. (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1206 - This variant has been shown to be paternally inherited (by trio analysis). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.77

Cadd

Benign

Dann

Benign

0.56

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.80

dbscSNV1_RF

Benign

0.62

SpliceAI score (max)

0.41

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.41

Position offset: -3

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