rs114248590

chr2-237344942-G-A

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6 BP7

The NM_004369.4(COL6A3):c.7173C>T(p.Tyr2391=) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000948 in 1,614,072 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00014 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000090 (1 hom.)
• Consequence: COL6A3 NM_004369.4 splice_region, synonymous
• Scores: Splicing: ADA: 0.00002099
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2
• Conservation: PhyloP100: -0.0500

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]

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.86).
• BP6: Variant 2-237344942-G-A is Benign according to our data. Variant chr2-237344942-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 281614.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1, Benign=1}.
• BP7: Synonymous conserved (PhyloP=-0.05 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL6A3	NM_004369.4	c.7173C>T	p.Tyr2391=	splice_region_variant, synonymous_variant	35/44	ENST00000295550.9
COL6A3	NM_057167.4	c.6555C>T	p.Tyr2185=	splice_region_variant, synonymous_variant	34/43
COL6A3	NM_057166.5	c.5352C>T	p.Tyr1784=	splice_region_variant, synonymous_variant	32/41

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL6A3	ENST00000295550.9	c.7173C>T	p.Tyr2391=	splice_region_variant, synonymous_variant	35/44	1	NM_004369.4	P1
COL6A3	ENST00000472056.5	c.5352C>T	p.Tyr1784=	splice_region_variant, synonymous_variant	32/41	1
COL6A3	ENST00000353578.9	c.6555C>T	p.Tyr2185=	splice_region_variant, synonymous_variant	34/43	5
COL6A3	ENST00000491769.1	n.1427C>T		splice_region_variant, non_coding_transcript_exon_variant	12/20	5

Frequencies

GnomAD3 genomes AF: 0.000131 AC: 20 AN: 152132 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000193

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000385

Gnomad SAS AF: 0.00124

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000152 AC: 38 AN: 250678 Hom.: 0 AF XY: 0.000184 AC XY: 25 AN XY: 135564

Gnomad AFR exome AF: 0.000185

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000381

Gnomad SAS exome AF: 0.000654

Gnomad FIN exome AF: 0.0000462

Gnomad NFE exome AF: 0.0000530

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000903 AC: 132 AN: 1461822 Hom.: 1 Cov.: 34 AF XY: 0.000110 AC XY: 80 AN XY: 727216

Gnomad4 AFR exome AF: 0.000418

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000554

Gnomad4 SAS exome AF: 0.000707

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000243

Gnomad4 OTH exome AF: 0.0000993

GnomAD4 genome AF: 0.000138 AC: 21 AN: 152250 Hom.: 0 Cov.: 32 AF XY: 0.000188 AC XY: 14 AN XY: 74436

Gnomad4 AFR AF: 0.000217

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000386

Gnomad4 SAS AF: 0.00125

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000969 Hom.: 0

Bravo AF: 0.000125

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Feb 06, 2018

- -

Bethlem myopathy 1A Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jan 29, 2024

- -

Collagen 6-related myopathy Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.86
Cadd	Benign	1.3
Dann	Benign	0.17

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000021
dbscSNV1_RF	Benign	0.054
SpliceAI score (max)		0.030		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

Other links and lift over

dbSNP: rs114248590; hg19: chr2-238253585; COSMIC: COSV55087325; COSMIC: COSV55087325;