rs368379003

Positions:

• chr2-237365879-C-A
• chr2-237365879-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_004369.4(COL6A3):​c.5657G>T​(p.Arg1886Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1886H) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL6A3 NM_004369.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.40

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.82

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL6A3	NM_004369.4	c.5657G>T	p.Arg1886Leu	missense_variant	12/44	ENST00000295550.9
COL6A3	NM_057167.4	c.5039G>T	p.Arg1680Leu	missense_variant	11/43
COL6A3	NM_057166.5	c.3836G>T	p.Arg1279Leu	missense_variant	9/41

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL6A3	ENST00000295550.9	c.5657G>T	p.Arg1886Leu	missense_variant	12/44	1	NM_004369.4	P1
COL6A3	ENST00000472056.5	c.3836G>T	p.Arg1279Leu	missense_variant	9/41	1
COL6A3	ENST00000353578.9	c.5039G>T	p.Arg1680Leu	missense_variant	11/43	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.10
CADD	Benign	19
DANN	Benign	0.90
DEOGEN2	Uncertain	0.57	.;D;.;T;.
Eigen	Uncertain	0.50
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.87	D;D;D;D;.
M_CAP	Benign	0.041	D
MetaRNN	Pathogenic	0.82	D;D;D;D;D
MetaSVM	Benign	-0.57	T
MutationAssessor	Uncertain	2.7	.;M;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Benign	0.43	T
PROVEAN	Uncertain	-4.2	D;D;D;.;D
REVEL	Uncertain	0.32
Sift	Uncertain	0.0040	D;D;D;.;D
Sift4G	Uncertain	0.0050	D;D;D;D;D
Polyphen		1.0	D;D;.;.;D
Vest4		0.80
MutPred		0.57		.;Loss of MoRF binding (P = 0.023);.;.;.;
MVP		0.80
MPC		0.61
ClinPred		0.96	D
GERP RS		5.3
Varity_R		0.36
gMVP		0.59

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: rs368379003; hg19: chr2-238274522;