rs193922955

Positions:

• chr3-49531086-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_004393.6(DAG1):​c.575C>T​(p.Thr192Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: DAG1 NM_004393.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1 O:1
• Conservation: PhyloP100: 7.86

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.926

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DAG1	NM_004393.6	c.575C>T	p.Thr192Met	missense_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.575C>T	p.Thr192Met	missense_variant	3/3	1	NM_004393.6	ENSP00000312435	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461892 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2P Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Mar 10, 2011

- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 13, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies have shown that this missense change affects DAG1 function (PMID: 21388311, 29036200, 31097590). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 31762). This missense change has been observed in individual(s) with muscular dystrophy-dystroglycanopathy (PMID: 21388311). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 192 of the DAG1 protein (p.Thr192Met). -

not provided Other:1

not provided, no classification provided

curation

Leiden Muscular Dystrophy (DAG1)

May 13, 2011

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.60
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.93	D;D;D;D;D;D
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.97	D;.;.;.;.;.
M_CAP	Uncertain	0.15	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D;D
MetaSVM	Uncertain	0.35	D
MutationAssessor	Uncertain	2.7	M;M;M;M;M;M
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-3.9	D;D;D;D;D;D
REVEL	Pathogenic	0.82
Sift	Pathogenic	0.0	D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D
Polyphen		1.0	D;D;D;D;D;D
Vest4		0.88
MutPred		0.75		Gain of catalytic residue at V188 (P = 0.0308);Gain of catalytic residue at V188 (P = 0.0308);Gain of catalytic residue at V188 (P = 0.0308);Gain of catalytic residue at V188 (P = 0.0308);Gain of catalytic residue at V188 (P = 0.0308);Gain of catalytic residue at V188 (P = 0.0308);
MVP		0.93
MPC		0.98
ClinPred		0.99	D
GERP RS		5.9
Varity_R		0.65
gMVP		0.77

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: rs193922955; hg19: chr3-49568519;