2-237324820-C-A

Position:

• chr2-237324820-C-A

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6_Moderate

The NM_004369.4(COL6A3):​c.9494-6G>T 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 0.000013 in 1,612,878 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: COL6A3 NM_004369.4 splice_region, splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.00002120
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.656

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=-0.82).
• BP6: Variant 2-237324820-C-A is Benign according to our data. Variant chr2-237324820-C-A is described in ClinVar as [Likely_benign]. Clinvar id is 702445.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL6A3	NM_004369.4	c.9494-6G>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000295550.9	NP_004360.2
COL6A3	NM_057166.5	c.7673-6G>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant			NP_476507.3
COL6A3	NM_057167.4	c.8876-6G>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant			NP_476508.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL6A3	ENST00000295550.9	c.9494-6G>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_004369.4	ENSP00000295550	P1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 151896 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000242

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000386

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000479

GnomAD3 exomes AF: 0.0000242 AC: 6 AN: 247698 Hom.: 0 AF XY: 0.0000298 AC XY: 4 AN XY: 134068

Gnomad AFR exome AF: 0.0000617

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000163

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000328

GnomAD4 exome AF: 0.0000116 AC: 17 AN: 1460864 Hom.: 0 Cov.: 31 AF XY: 0.0000151 AC XY: 11 AN XY: 726702

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000101

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.000166

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152014 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74304

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000387

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.000474

Bravo AF: 0.0000189

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Bethlem myopathy 1A Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 16, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.82
CADD	Benign	0.55
DANN	Benign	0.67

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000021
dbscSNV1_RF	Benign	0.0040
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

Other links and lift over

dbSNP: rs367899223; hg19: chr2-238233463;