chr21-45986676-C-G

Variant names:

• chr21-45986676-C-G
• rs61751027
• NM_001848.3:c.579C>G

Variant summary

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

The ENST00000361866.8(COL6A1):​c.579C>G​(p.Pro193Pro) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000129 in 1,547,206 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. P193P) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 7.2e-7 (0 hom.)
• Consequence: COL6A1 ENST00000361866.8 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -1.21
• Publications: 1 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=-0.64).
• BP7: Synonymous conserved (PhyloP=-1.21 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000361866.8. 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.579C>G	p.Pro193Pro	synonymous	Exon 4 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.579C>G	p.Pro193Pro	synonymous	Exon 4 of 35	ENSP00000355180.3

Frequencies

GnomAD3 genomes AF: 0.00000662 AC: 1 AN: 151124 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000648 AC: 1 AN: 154360 AF XY: 0.0000123

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: 0.0000165

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 7.16e-7 AC: 1 AN: 1396082 Hom.: 0 Cov.: 33 AF XY: 0.00000145 AC XY: 1 AN XY: 688744

African (AFR) AF: 0.00 AC: 0 AN: 31604

American (AMR) AF: 0.0000279 AC: 1 AN: 35842

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25188

East Asian (EAS) AF: 0.00 AC: 0 AN: 35746

South Asian (SAS) AF: 0.00 AC: 0 AN: 79230

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 45964

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5520

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1079046

Other (OTH) AF: 0.00 AC: 0 AN: 57942

GnomAD4 genome AF: 0.00000662 AC: 1 AN: 151124 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 73776

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 40822

American (AMR) AF: 0.00 AC: 0 AN: 15226

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3460

East Asian (EAS) AF: 0.00 AC: 0 AN: 5086

South Asian (SAS) AF: 0.00 AC: 0 AN: 4772

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10596

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67850

Other (OTH) AF: 0.00 AC: 0 AN: 2086

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 2

Bravo AF: 0.0000113

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.64
CADD	Benign	0.012
DANN	Benign	0.38
PhyloP100		-1.2

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: rs61751027; hg19: chr21-47406590;