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Limb Girdle Muscular Dystrophy Type 2Y via the TOR1AIP1 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
3833 TOR1AIP1 81479 81479,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
3833TOR1AIP181479 81479,81479 $890 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 backbone).

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

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

For Sanger Sequencing click here.

Turnaround Time

18 days on average for standard orders or 13 days 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.

EMAIL CONTACTS

Genetic Counselors

Geneticist

  • Angela Gruber, PhD

Clinical Features and Genetics

Clinical Features

Limb girdle muscular dystrophy (LGMD) is a descriptive term for a group of disorders with atrophy and weakness of proximal girdle muscles and typical sparing of the heart and bulbar muscles. Clinical severity, age of onset, and disease progression are highly variable among the subtypes (Sáenz et al. 2005). Serum creatine kinase levels are typically elevated, and muscle biopsies demonstrate a dystrophic process. For comprehensive reviews, see Pegoraro and Hoffman (2012) and Nigro and Savarese (2014).

Two different families thus far have had pathogenic TOR1AIP1 variants identified. In a consanguineous Turkish family with three affected individuals, homozygosity mapping was used to identify the TOR1AIP1 gene as a candidate for sequencing. These individuals presented with proximal limb-girdle weakness during childhood which later progressed to distal weakness with atrophy, rigid spine, and contractures of proximal and distal hand joints. Cardiomyopathy and respiratory involvement were also noted in adulthood. In a second family with one affected individual, TOR1AIP1 variants were detected via whole exome sequencing (WES). This patient presented with LGMD-like weakness and severe dilated cardiomyopathy at 12 years of age. The muscle biopsy from this patient was consistent with a dystrophic process.

Genetics

Limb girdle muscular dystrophy type 2Y is inherited as an autosomal recessive disorder. So far, only missense and small deletion variants have been observed (Ghaoui et al. 2015; Kayman-Kurekci et al. 2014). The TOR1AIP1 gene encodes the lamina-associated polypeptide 1B (LAP1B) protein which is a type-2 integral membrane protein located in the inner nuclear membrane and shown to bind both A- and B-type lamins (Kayman-Kurekci et al 2014). The full function of this protein is not completely understood; however, the LAP1B protein is widely expressed in a variety of tissues, including skeletal muscle.

Clinical Sensitivity - Sequencing with CNV PGxome

Too few cases of LGMD2Y have been reported to provide a numeric estimate of clinical or analytical sensitivity. However, pathogenic variants in TOR1AIP1 appear to be a rare cause of LGMD. Analytical sensitivity could be high as the reported pathogenic variants are detectable by sequencing.

Thus far, no large deletions or duplications involving the TOR1AIP1 gene have been reported.

Testing Strategy

This test provides full coverage of all coding exons of the TOR1AIP1 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

Individuals with a limb-girdle distribution of weakness as well as cardiac or respiratory involvement. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in TOR1AIP1.

Gene

Official Gene Symbol OMIM ID
TOR1AIP1 614512
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
Limb-Girdle Muscular Dystrophy, Type 2Y AR 617072

Citations

  • Ghaoui R. et al. 2015. Jama Neurology. 72: 1424-32. PubMed ID: 26436962
  • Kayman-Kurekci G. et al. 2014. Neuromuscular Disorders. 24: 624-33. PubMed ID: 24856141
  • Nigro V., Savarese M. 2014. Acta Myologica : myopathies and Cardiomyopathies. 33: 1-12. PubMed ID: 24843229
  • Pegoraro E., Hoffman E.P. 2012. Limb-Girdle Muscular Dystrophy Overview. In: Pagon RA, Adam MP, Bird TD, Dolan CR, Fong C-T, and Stephens K, editors. GeneReviews™, Seattle (WA): University of Washington, Seattle. PubMed ID: 20301582
  • Sáenz A. et al. 2005. Brain 128: 732–42. PubMed ID: 15689361

Ordering/Specimens

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


Specimen Types

Specimen Requirements and Shipping Details

PGxome (Exome) Sequencing Panel

PGnome (Genome) Sequencing Panel

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ORDER OPTIONS

View Ordering Instructions

1) Select Test Method (Backbone)


1) Select Test Type


2) Select Additional Test Options

STAT and Prenatal Test Options are not available with Patient Plus.

No Additional Test Options are available for this test.

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