21-46003746-G-C

Variant names:

• chr21-46003746-G-C
• rs111451684
• NM_001848.3:c.2820G>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_001848.3(COL6A1):​c.2820G>C​(p.Leu940Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,612,768 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. L940L) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 35)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COL6A1 NM_001848.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.35
• 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: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.51).
• BP7: Synonymous conserved (PhyloP=2.35 with no splicing effect.

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.2820G>C	p.Leu940Leu	synonymous	Exon 35 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.2820G>C	p.Leu940Leu	synonymous	Exon 35 of 35	ENSP00000355180.3
	COL6A1	ENST00000498614.5	TSL:1	n.1054G>C		non_coding_transcript_exon	Exon 6 of 6
	COL6A1	ENST00000612273.2	TSL:5	c.945G>C	p.Leu315Leu	synonymous	Exon 6 of 7	ENSP00000483630.2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152264 Hom.: 0 Cov.: 35

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460504 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 726580

African (AFR) AF: 0.0000299 AC: 1 AN: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44698

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26110

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52320

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111842

Other (OTH) AF: 0.00 AC: 0 AN: 60352

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152264 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 74390

African (AFR) AF: 0.0000241 AC: 1 AN: 41468

American (AMR) AF: 0.00 AC: 0 AN: 15294

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4838

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10628

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68050

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.51
CADD	Benign	7.2
DANN	Benign	0.72
PhyloP100		2.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs111451684; hg19: chr21-47423660;