NM_001848.3:c.19C>T

Variant names:

• chr21-45981869-C-T
• rs1280132890
• NM_001848.3:c.19C>T

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.19C>T​(p.Leu7Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000692 in 1,444,798 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.

• Frequency:
  • Genomes: not found (cov: 29)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: COL6A1 NM_001848.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.378
• 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: AR, AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P
• collagen 6-related myopathy

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

  Inheritance: AD, AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• 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=-0.54).
• BP7: Synonymous conserved (PhyloP=0.378 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.19C>T	p.Leu7Leu	synonymous	Exon 1 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.19C>T	p.Leu7Leu	synonymous	Exon 1 of 35	ENSP00000355180.3	P12109
	COL6A1	ENST00000866134.1		c.19C>T	p.Leu7Leu	synonymous	Exon 1 of 7	ENSP00000536193.1

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD2 exomes AF: 0.00000465 AC: 1 AN: 215154 AF XY: 0.00000848

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: 6.92e-7 AC: 1 AN: 1444798 Hom.: 0 Cov.: 33 AF XY: 0.00000139 AC XY: 1 AN XY: 717604

⚠️ 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: 33096

American (AMR) AF: 0.00 AC: 0 AN: 43166

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25798

East Asian (EAS) AF: 0.00 AC: 0 AN: 38632

South Asian (SAS) AF: 0.0000120 AC: 1 AN: 83410

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50674

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4676

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1105772

Other (OTH) AF: 0.00 AC: 0 AN: 59574

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 29

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.54
CADD	Benign	8.9
DANN	Benign	0.91
PhyloP100		0.38
PromoterAI		-0.037	Neutral

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: rs1280132890; hg19: chr21-47401783;