NM_001849.4:c.2607C>A

Variant names:

• chr21-46132099-C-A
• rs150219725
• NM_001849.4:c.2607C>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 4P and 4B. PM1 PM2 BP4_Strong

The NM_001849.4(COL6A2):​c.2607C>A​(p.Asp869Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000693 in 1,441,976 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D869Y) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: COL6A2 NM_001849.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.121
• Publications: 1 publications found

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]

COL6A2 Gene-Disease associations (from GenCC):

• collagen 6-related myopathy

  Inheritance: AD, AR Classification: DEFINITIVE Submitted by: ClinGen
• Ullrich congenital muscular dystrophy 1B

  Inheritance: AR, AD Classification: DEFINITIVE Submitted by: G2P
• Bethlem myopathy 1A

  Inheritance: AD, AR Classification: STRONG Submitted by: Genomics England PanelApp
• Ullrich congenital muscular dystrophy 1A

  Inheritance: AD, AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• Bethlem myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Ullrich congenital muscular dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• myosclerosis

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 7 benign, 10 uncertain in NM_001849.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.061819196).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL6A2	NM_001849.4	c.2607C>A	p.Asp869Glu	missense_variant	Exon 28 of 28	ENST00000300527.9	NP_001840.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL6A2	ENST00000300527.9	c.2607C>A	p.Asp869Glu	missense_variant	Exon 28 of 28	1	NM_001849.4	ENSP00000300527.4

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD2 exomes AF: 0.00000482 AC: 1 AN: 207658 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000108

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.93e-7 AC: 1 AN: 1441976 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 716732

African (AFR) AF: 0.00 AC: 0 AN: 32964

American (AMR) AF: 0.00 AC: 0 AN: 42506

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25848

East Asian (EAS) AF: 0.00 AC: 0 AN: 38410

South Asian (SAS) AF: 0.00 AC: 0 AN: 84238

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 47378

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5752

European-Non Finnish (NFE) AF: 9.05e-7 AC: 1 AN: 1105228

Other (OTH) AF: 0.00 AC: 0 AN: 59652

GnomAD4 genome Cov.: 34

Alfa AF: 0.0000224 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Nov 30, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.42
CADD	Benign	0.032
DANN	Benign	0.77
DEOGEN2	Benign	0.18	T
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.15	N
LIST_S2	Benign	0.44	T
M_CAP	Benign	0.034	D
MetaRNN	Benign	0.062	T
MetaSVM	Benign	-0.90	T
MutationAssessor	Benign	1.7	L
PhyloP100		-0.12
PrimateAI	Benign	0.45	T
PROVEAN	Benign	-0.060	N
REVEL	Benign	0.12
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Polyphen		0.0010	B
Vest4		0.12
MutPred		0.35		Gain of loop (P = 0.069);
MVP		0.60
MPC		0.13
ClinPred		0.029	T
GERP RS		-1.2
Varity_R		0.042
gMVP		0.47
Mutation Taster		=88/12	polymorphism

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

Other links and lift over

dbSNP: rs150219725; hg19: chr21-47552013; COSMIC: COSV52424260; COSMIC: COSV52424260;