21-45992791-G-C

Variant names:

• chr21-45992791-G-C
• rs35059000
• NM_001848.3:c.1316G>C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001848.3(COL6A1):​c.1316G>C​(p.Arg439Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. R439W) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 34)
• Consequence: COL6A1 NM_001848.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.39
• Publications: 0 publications found

Genes affected

COL6A1 (HGNC:2211): (collagen type VI alpha 1 chain) The collagens are a superfamily of proteins that play a role in maintaining the integrity of various tissues. Collagens are extracellular matrix proteins and have a triple-helical domain as their common structural element. Collagen VI is a major structural component of microfibrils. The basic structural unit of collagen VI is a heterotrimer of the alpha1(VI), alpha2(VI), and alpha3(VI) chains. The alpha2(VI) and alpha3(VI) chains are encoded by the COL6A2 and COL6A3 genes, respectively. The protein encoded by this gene is the alpha 1 subunit of type VI collagen (alpha1(VI) chain). Mutations in the genes that code for the collagen VI subunits result in the autosomal dominant disorder, Bethlem myopathy. [provided by RefSeq, Jul 2008]

COL6A1 Gene-Disease associations (from GenCC):

• collagen 6-related myopathy

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

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P
• Ullrich congenital muscular dystrophy 1A

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

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

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001848.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL6A1	NM_001848.3	MANE Select	c.1316G>C	p.Arg439Pro	missense	Exon 19 of 35	NP_001839.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL6A1	ENST00000361866.8	TSL:1 MANE Select	c.1316G>C	p.Arg439Pro	missense	Exon 19 of 35	ENSP00000355180.3

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 34

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.29
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.64	D
Eigen	Benign	-0.018
Eigen_PC	Benign	-0.0054
FATHMM_MKL	Benign	0.73	D
LIST_S2	Benign	0.74	T
M_CAP	Pathogenic	0.45	D
MetaRNN	Uncertain	0.73	D
MetaSVM	Uncertain	0.15	D
MutationAssessor	Benign	-0.055	N
PhyloP100		2.4
PrimateAI	Pathogenic	0.82	D
PROVEAN	Uncertain	-3.5	D
REVEL	Uncertain	0.62
Sift	Benign	0.17	T
Sift4G	Benign	0.24	T
Polyphen		1.0	D
Vest4		0.60
MutPred		0.40		Loss of methylation at R439 (P = 0.0084)
MVP		0.91
MPC		0.98
ClinPred		0.96	D
GERP RS		4.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.71
gMVP		0.73
Mutation Taster		=70/30	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs35059000; hg19: chr21-47412705;