2-237324820-C-T

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 2P and 12B. PM2 BP4_Strong BP6_Very_Strong

The NM_004369.4(COL6A3):c.9494-6G>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 0.0000143 in 1,612,760 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 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000014 (0 hom.)
• Consequence: COL6A3 NM_004369.4 splice_region, splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.00006213
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts U:1 B:2
• 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 Benign. Variant got -10 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.84).
• BP6: Variant 2-237324820-C-T is Benign according to our data. Variant chr2-237324820-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 1809778.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL6A3	NM_004369.4	c.9494-6G>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000295550.9
COL6A3	NM_057166.5	c.7673-6G>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant
COL6A3	NM_057167.4	c.8876-6G>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	c.9494-6G>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_004369.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 151896 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000656

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: 0.000479

GnomAD3 exomes AF: 0.0000161 AC: 4 AN: 247698 Hom.: 0 AF XY: 0.00000746 AC XY: 1 AN XY: 134068

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000868

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000144 AC: 21 AN: 1460864 Hom.: 0 Cov.: 31 AF XY: 0.0000138 AC XY: 10 AN XY: 726702

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000157

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000348

Gnomad4 FIN exome AF: 0.0000190

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.0000663

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 151896 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74176

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000656

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: 0.000479

Bravo AF: 0.0000264

ClinVar

Significance: Likely benign

Submissions summary: Uncertain:1 Benign:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Myopathy Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Institute of Human Genetics, University of Wuerzburg

-

- -

Bethlem myopathy 1A Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

May 21, 2022

- -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Jul 01, 2023

COL6A3: BP4 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.84
Cadd	Benign	1.5
Dann	Benign	0.76

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000062
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;