21-46132153-G-A

Position:

• chr21-46132153-G-A

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_Strong BP6 BP7

The NM_001849.4(COL6A2):​c.2661G>A​(p.Glu887=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00031 in 1,569,366 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00048 (0 hom., cov: 34)
  • Exomes 𝑓: 0.00029 (1 hom.)
• Consequence: COL6A2 NM_001849.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:3
• Conservation: PhyloP100: 1.61

Genes affected

COL6A2 (HGNC:2212): (collagen type VI alpha 2 chain) This gene encodes one of the three alpha chains of type VI collagen, a beaded filament collagen found in most connective tissues. The product of this gene contains several domains similar to von Willebrand Factor type A domains. 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 this gene are associated with Bethlem myopathy and Ullrich scleroatonic muscular dystrophy. Three transcript variants have been identified for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -6 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.61).
• BP6: Variant 21-46132153-G-A is Benign according to our data. Variant chr21-46132153-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 284815.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Uncertain_significance=1}.
• BP7: Synonymous conserved (PhyloP=1.61 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL6A2	NM_001849.4	c.2661G>A	p.Glu887=	synonymous_variant	28/28	ENST00000300527.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL6A2	ENST00000300527.9	c.2661G>A	p.Glu887=	synonymous_variant	28/28	1	NM_001849.4	P1

Frequencies

GnomAD3 genomes AF: 0.000480 AC: 73 AN: 152198 Hom.: 0 Cov.: 34

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00242

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.000753

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000368

Gnomad OTH AF: 0.000956

GnomAD3 exomes AF: 0.000236 AC: 41 AN: 173690 Hom.: 0 AF XY: 0.000308 AC XY: 29 AN XY: 94096

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000451

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.000877

Gnomad NFE exome AF: 0.000222

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000291 AC: 413 AN: 1417168 Hom.: 1 Cov.: 33 AF XY: 0.000284 AC XY: 199 AN XY: 701678

Gnomad4 AFR exome AF: 0.0000310

Gnomad4 AMR exome AF: 0.000448

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.000817

Gnomad4 NFE exome AF: 0.000313

Gnomad4 OTH exome AF: 0.000221

GnomAD4 genome AF: 0.000480 AC: 73 AN: 152198 Hom.: 0 Cov.: 34 AF XY: 0.000592 AC XY: 44 AN XY: 74352

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00242

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.000753

Gnomad4 NFE AF: 0.000368

Gnomad4 OTH AF: 0.000956

Alfa AF: 0.000323 Hom.: 0

Bravo AF: 0.000344

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Nov 06, 2017

- -

Myosclerosis Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jun 14, 2016

- -

Bethlem myopathy 1A Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 06, 2023

- -

Collagen 6-related myopathy Benign:1

Likely 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 likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.61
CADD	Benign	6.2
DANN	Benign	0.87

Splicing

Name	Calibrated prediction	Score	Prediction
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: rs148249892; hg19: chr21-47552067;