rs764099825

Variant names:

• chr21-46002026-G-A
• rs764099825
• NM_001848.3:c.2022G>A
• COL6A1 p.Val674Val

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 2P and 11B. PM2 BP4_Moderate BP6_Very_Strong BP7

The NM_001848.3(COL6A1):​c.2022G>A​(p.Val674Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,336 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: COL6A1 NM_001848.3 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: 2.30
• 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):

• Bethlem myopathy 1A

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P
• collagen 6-related myopathy

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

  Inheritance: AR, AD 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: Benign. The variant received -9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.45).
• BP6: Variant 21-46002026-G-A is Benign according to our data. Variant chr21-46002026-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 543027.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=2.3 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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL6A1	NM_001848.3	MANE Select	c.2022G>A	p.Val674Val	synonymous	Exon 31 of 35	NP_001839.2	P12109

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL6A1	ENST00000361866.8	TSL:1 MANE Select	c.2022G>A	p.Val674Val	synonymous	Exon 31 of 35	ENSP00000355180.3	P12109
	COL6A1	ENST00000498614.5	TSL:1	n.256G>A		non_coding_transcript_exon	Exon 2 of 6
	COL6A1	ENST00000612273.2	TSL:5	c.147G>A	p.Val49Val	synonymous	Exon 2 of 7	ENSP00000483630.2	A0A087X0S5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000410 AC: 1 AN: 244008 AF XY: 0.00000754

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460336 Hom.: 0 Cov.: 35 AF XY: 0.00000138 AC XY: 1 AN XY: 726482

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

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44708

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26108

East Asian (EAS) AF: 0.00 AC: 0 AN: 39682

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86178

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52230

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111848

Other (OTH) AF: 0.00 AC: 0 AN: 60340

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000203476), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Likely benign

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	-	1	Bethlem myopathy 1A (1)
-	-	1	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.45
CADD	Benign	14
DANN	Benign	0.72
PhyloP100		2.3
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.11		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs764099825;

hg19: chr21-47421940;