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Dystroglycanopathy via the DAG1 Gene

Summary and Pricing

Test Method

Exome Sequencing with CNV Detection
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
DAG1 81479 81479,81479 $990
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
8473DAG181479 81479,81479 $990 Order Options and Pricing

Pricing Comments

Our favored testing approach is exome based NextGen sequencing with CNV analysis. This will allow cost effective reflexing to PGxome or other exome based tests. However, if full gene Sanger sequencing is desired for STAT turnaround time, insurance, or other reasons, please see link below for Test Code, pricing, and turnaround time information. If the Sanger option is selected, CNV detection may be ordered through Test #600.

An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.

Click here for costs to reflex to whole PGxome (if original test is on PGxome Sequencing platform).

Click here for costs to reflex to whole PGnome (if original test is on PGnome Sequencing platform).

The Sanger Sequencing method for this test is NY State approved.

For Sanger Sequencing click here.

Turnaround Time

3 weeks on average for standard orders or 2 weeks on average for STAT orders.

Please note: Once the testing process begins, an Estimated Report Date (ERD) range will be displayed in the portal. This is the most accurate prediction of when your report will be complete and may differ from the average TAT published on our website. About 85% of our tests will be reported within or before the ERD range. We will notify you of significant delays or holds which will impact the ERD. Learn more about turnaround times here.

Targeted Testing

For ordering sequencing of targeted known variants, go to our Targeted Variants page.


Genetic Counselors


  • Angela Gruber, PhD

Clinical Features and Genetics

Clinical Features

Dystroglycan is the central component of the muscle dystrophin-glycoprotein complex ([DGC] Ervasti et al. Nature 345:315-319, 1990, Michele and Campbell. J Biol Chem 278:15457-15460, 2003). Beta-dystroglycan spans the sarcolemma, binding dystrophin intracellulary and alpha-dystroglycan extracellularly. Alpha-dystroglycan is connected to the basal lamina by way of linkage to laminin (Ibraghimov-Beskrovnaya et al. Nature 355:696-702, 1992). Alpha-dystroglycan binds additional proteins with laminin G-like domains such as agrin and perlecan in muscle and neurexin in brain (Sugita et al. J Cell Biol 154:435-445, 2001). The gene DAG1 (OMIM 128239) encodes one precursor peptide that is cleaved post-translationally to form the alpha and beta subunits of dystroglycan. Both subunits undergo further modification by N- and O-linked glycosylation; however, alpha-dystroglycan undergoes extensive O-linked glycosylation (Ibraghimov-Beskrovnaya et al. Hum Mol Genet 2:1651-1657, 1993). The glycosylation status of dystroglycan is critical for ligand binding as well as for pathogenesis (Michele et al. Nature 418:417-422, 2002; Muntoni et al. Curr Opin Neurol 17:205-209, 2004; Barresi and Campbell. J Cell Sci 119:199-207, 2006).


Alpha- and beta-dystroglycan are encoded by the DAG1 gene located on chr 3p21. The 895 residue precursor peptide is directed to the endoplasmic reticulum via a 29 amino acid N-terminal signal peptide. Cleavage of the precursor peptide occurs at p.Ser654 to yield core alpha- and beta-dystroglycan proteins. A single transmembrane domain (residues 751-774) directs beta-dystroglycan to span the sarcolemma. Interaction between dystrophin and beta-dystroglycan occurs at a PPXY motif (p.Pro828_p.Tyr831) at the C-terminus of beta dystroglycan. The predicted mass of alpha-dystroglycan core protein and the corresponding protein isolated from tissue differ because of extensive species- and tissue-specific O-linked glycosylation of the central mucin domain between residues 312 and 485 (Barresi and Campbell, 2006). Studies in mouse demonstrate that constitutional DAG1 variants are lethal in the early embryonic period secondary to disruption of Reichert’s membrane (Williamson et al. Hum Mol Genet 6:831-841, 1997; Henry and Campbell Cell 95:859-870, 1998). Transgenic animals in which expression of the knockout DAG1 gene construct is limited to the brain show structural malformations like those seen in patients with congenital muscular dystrophies, as well as loss of high affinity binding to laminin (Moore et al. Nature 418:422-425). One patient with limb girdle muscular dystrophy and severe cognitive impairment was found to be homozygous for a DAG1 variant (p.Thr192Met, Hara et al. New Eng J Med 364: 939-946, 2011).

Clinical Sensitivity - Sequencing with CNV PGxome

At this time there is no known clinical utility for this test. Analytical and clinical sensitivity are unknown because there are no reported genotype-phenotype correlations for dystroglycan variants in humans. Findings generated from this test should not alone be considered as diagnostic.

Testing Strategy

This test provides full coverage of all coding exons of the DAG1 gene plus 10 bases of flanking noncoding DNA in all available transcripts along with other non-coding regions in which pathogenic variants have been identified at PreventionGenetics or reported elsewhere. We define full coverage as >20X NGS reads or Sanger sequencing. PGnome panels typically provide slightly increased coverage over the PGxome equivalent. PGnome sequencing panels have the added benefit of additional analysis and reporting of deep intronic regions (where applicable).

Dependent on the sequencing backbone selected for this testing, discounted reflex testing to any other similar backbone-based test is available (i.e., PGxome panel to whole PGxome; PGnome panel to whole PGnome).

Indications for Test

Patients with clinically- or histopathologically-diagnosed dystroglycanopathy. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in DAG1.


Official Gene Symbol OMIM ID
DAG1 128239
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT


  • Barresi, R. and Campbell, K. P. (2006). "Dystroglycan: from biosynthesis to pathogenesis of human disease." J Cell Sci 119(Pt 2): 199-207. PubMed ID: 16410545
  • Ervasti, J. M., et.al. (1990). "Deficiency of a glycoprotein component of the dystrophin complex in dystrophic muscle." Nature 345(6273): 315-9. PubMed ID: 2188135
  • Hara, Y., et.al. (2011). "A dystroglycan mutation associated with limb-girdle muscular dystrophy." N Engl J Med 364(10): 939-46. PubMed ID: 21388311
  • Henry, M. D., Campbell, K. P. (1998). "A role for dystroglycan in basement membrane assembly." Cell 95(6): 859-70. PubMed ID: 9865703
  • Ibraghimov-Beskrovnaya, O., et.al. (1992). "Primary structure of dystrophin-associated glycoproteins linking dystrophin to the extracellular matrix." Nature 355(6362): 696-702. PubMed ID: 1741056
  • Ibraghimov-Beskrovnaya, O., et.al. (1993). "Human dystroglycan: skeletal muscle cDNA, genomic structure, origin of tissue specific isoforms and chromosomal localization." Hum Mol Genet 2(10): 1651-7. PubMed ID: 8268918
  • Michele, D. E., Campbell, K. P. (2003). "Dystrophin-glycoprotein complex: post-translational processing and dystroglycan function." J Biol Chem 278(18): 15457-60. PubMed ID: 12556455
  • Michele, D. E., et.al. (2002). "Post-translational disruption of dystroglycan-ligand interactions in congenital muscular dystrophies." Nature 418(6896): 417-22. PubMed ID: 12140558
  • Moore, S. A., et.al. (2002). "Deletion of brain dystroglycan recapitulates aspects of congenital muscular dystrophy." Nature 418(6896): 422-5. PubMed ID: 12140559
  • Muntoni, F., et.al. (2004). "Defective glycosylation in congenital muscular dystrophies." Curr Opin Neurol 17(2): 205-9. PubMed ID: 15021250
  • Sugita, S., et.al. (2001). "A stoichiometric complex of neurexins and dystroglycan in brain." J Cell Biol 154(2): 435-45. PubMed ID: 11470830
  • Williamson, R. A., et.al. (1997). "Dystroglycan is essential for early embryonic development: disruption of Reichert's membrane in Dag1-null mice." Hum Mol Genet 6(6): 831-41. PubMed ID: 9175728


Ordering Options

We offer several options when ordering sequencing tests. For more information on these options, see our Ordering Instructions page. To view available options, click on the Order Options button within the test description.

myPrevent - Online Ordering

  • The test can be added to your online orders in the Summary and Pricing section.
  • Once the test has been added log in to myPrevent to fill out an online requisition form.
  • PGnome sequencing panels can be ordered via the myPrevent portal only at this time.

Requisition Form

  • A completed requisition form must accompany all specimens.
  • Billing information along with specimen and shipping instructions are within the requisition form.
  • All testing must be ordered by a qualified healthcare provider.

For Requisition Forms, visit our Forms page

If ordering a Duo or Trio test, the proband and all comparator samples are required to initiate testing. If we do not receive all required samples for the test ordered within 21 days, we will convert the order to the most effective testing strategy with the samples available. Prior authorization and/or billing in place may be impacted by a change in test code.

Specimen Types

Specimen Requirements and Shipping Details

PGxome (Exome) Sequencing Panel

PGnome (Genome) Sequencing Panel

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Note: acceptable specimen types are whole blood and DNA from whole blood only.
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