2-237324821-G-A

Position:

• chr2-237324821-G-A

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.9494-7C>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 0.000036 in 1,613,054 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 0.00016 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000023 (0 hom.)
• Consequence: COL6A3 NM_004369.4 splice_region, splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.00002692
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: -1.90

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=-0.87).
• BP6: Variant 2-237324821-G-A is Benign according to our data. Variant chr2-237324821-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 515415.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.9494-7C>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000295550.9
COL6A3	NM_057166.5	c.7673-7C>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant
COL6A3	NM_057167.4	c.8876-7C>T		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.9494-7C>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_004369.4	P1

Frequencies

GnomAD3 genomes AF: 0.000164 AC: 25 AN: 152084 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000556

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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: 0.0000444 AC: 11 AN: 247634 Hom.: 0 AF XY: 0.00000746 AC XY: 1 AN XY: 134042

Gnomad AFR exome AF: 0.000679

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: 0.0000226 AC: 33 AN: 1460970 Hom.: 0 Cov.: 31 AF XY: 0.0000193 AC XY: 14 AN XY: 726736

Gnomad4 AFR exome AF: 0.000657

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000899

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.000164 AC: 25 AN: 152084 Hom.: 0 Cov.: 32 AF XY: 0.000108 AC XY: 8 AN XY: 74298

Gnomad4 AFR AF: 0.000556

Gnomad4 AMR AF: 0.0000655

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

Alfa AF: 0.000200 Hom.: 0

Bravo AF: 0.000230

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Feb 15, 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

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jan 24, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.87
CADD	Benign	0.094
DANN	Benign	0.75

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000027
dbscSNV1_RF	Benign	0.0060
SpliceAI score (max)		0.020		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: rs374024399; hg19: chr2-238233464;