rs1553652503

Positions:

• chr3-49530950-CA-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_004393.6(DAG1):​c.440delA​(p.Gln147fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: DAG1 NM_004393.6 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.09

Genes affected

DAG1 (HGNC:2666): (dystroglycan 1) This gene encodes dystroglycan, a central component of dystrophin-glycoprotein complex that links the extracellular matrix and the cytoskeleton in the skeletal muscle. The encoded preproprotein undergoes O- and N-glycosylation, and proteolytic processing to generate alpha and beta subunits. Certain mutations in this gene are known to cause distinct forms of muscular dystrophy. Alternative splicing results in multiple transcript variants, all encoding the same protein. [provided by RefSeq, Nov 2015]

DAG1 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 7 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 3-49530950-CA-C is Pathogenic according to our data. Variant chr3-49530950-CA-C is described in ClinVar as [Pathogenic]. Clinvar id is 539125.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DAG1	NM_004393.6	c.440delA	p.Gln147fs	frameshift_variant	3/3	ENST00000308775.7	NP_004384.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DAG1	ENST00000308775.7	c.440delA	p.Gln147fs	frameshift_variant	3/3	1	NM_004393.6	ENSP00000312435.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A9;C4511963:Autosomal recessive limb-girdle muscular dystrophy type 2P Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 16, 2022

This variant has not been reported in the literature in individuals affected with DAG1-related conditions. For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the DAG1 protein in which other variant(s) (p.Phe152Leufs*3) have been determined to be pathogenic (Invitae). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. ClinVar contains an entry for this variant (Variation ID: 539125). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gln147Argfs*21) in the DAG1 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 749 amino acid(s) of the DAG1 protein. -

Computational scores

Source: dbNSFP v4.3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553652503; hg19: chr3-49568383;