chr21-46124639-G-A

Position:

• chr21-46124639-G-A

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_Strong BP6_Very_Strong BS1 BS2

The NM_001849.4(COL6A2):​c.1672-12G>A variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00179 in 1,612,802 control chromosomes in the GnomAD database, including 37 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0089 (15 hom., cov: 33)
  • Exomes 𝑓: 0.0010 (22 hom.)
• Consequence: COL6A2 NM_001849.4 intron
• Scores: Splicing: ADA: 0.0001694
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4
• Conservation: PhyloP100: 0.531

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 Benign. Variant got -20 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.75).
• BP6: Variant 21-46124639-G-A is Benign according to our data. Variant chr21-46124639-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 258318.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00891 (1355/152136) while in subpopulation AFR AF= 0.0304 (1259/41464). AF 95% confidence interval is 0.029. There are 15 homozygotes in gnomad4. There are 636 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd4 at 15 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL6A2	NM_001849.4	c.1672-12G>A		intron_variant		ENST00000300527.9	NP_001840.3
COL6A2	NM_058174.3	c.1672-12G>A		intron_variant			NP_478054.2
COL6A2	NM_058175.3	c.1672-12G>A		intron_variant			NP_478055.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL6A2	ENST00000300527.9	c.1672-12G>A		intron_variant		1	NM_001849.4	ENSP00000300527.4
COL6A2	ENST00000397763.6	c.1672-12G>A		intron_variant		5		ENSP00000380870.1
COL6A2	ENST00000409416.6	c.1672-12G>A		intron_variant		5		ENSP00000387115.1
COL6A2	ENST00000413758.1	c.295-12G>A		intron_variant		3		ENSP00000395751.1

Frequencies

GnomAD3 genomes AF: 0.00889 AC: 1352 AN: 152018 Hom.: 14 Cov.: 33

Gnomad AFR AF: 0.0304

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00386

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000414

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00633

Gnomad NFE AF: 0.000177

Gnomad OTH AF: 0.00956

GnomAD3 exomes AF: 0.00260 AC: 649 AN: 249892 Hom.: 9 AF XY: 0.00196 AC XY: 266 AN XY: 135608

Gnomad AFR exome AF: 0.0339

Gnomad AMR exome AF: 0.00229

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000160

Gnomad OTH exome AF: 0.00148

GnomAD4 exome AF: 0.00105 AC: 1531 AN: 1460666 Hom.: 22 Cov.: 35 AF XY: 0.000889 AC XY: 646 AN XY: 726646

Gnomad4 AFR exome AF: 0.0322

Gnomad4 AMR exome AF: 0.00224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000348

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000177

Gnomad4 OTH exome AF: 0.00245

GnomAD4 genome AF: 0.00891 AC: 1355 AN: 152136 Hom.: 15 Cov.: 33 AF XY: 0.00855 AC XY: 636 AN XY: 74364

Gnomad4 AFR AF: 0.0304

Gnomad4 AMR AF: 0.00386

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000177

Gnomad4 OTH AF: 0.00946

Alfa AF: 0.00163 Hom.: 0

Bravo AF: 0.0102

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:2

Benign, criteria provided, single submitter	clinical testing	GeneDx	Jan 06, 2017	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. -
Likely benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -

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. -

Bethlem myopathy 1A Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 19, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.75
CADD	Benign	5.7
DANN	Benign	0.69

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00017
dbscSNV1_RF	Benign	0.010
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: rs113857622; hg19: chr21-47544553;