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Heterotaxy via the LEFTY2 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
9107 LEFTY2 81479 81479,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
9107LEFTY281479 81479(x2) $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.

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

  • Fang Xu, PhD, FACMG

Clinical Features and Genetics

Clinical Features

Heterotaxy syndrome or situs ambiguus results from a failure to properly establish left-right asymmetry during embryogenesis resulting in an abnormal arrangement of thoracic or abdominal visceral organs, including the heart, lungs, liver, spleen, intestines, and stomach. Affected patients frequently have significant morbidity and mortality due to a wide variety of cyanotic congenital heart defects. Common defects besides cardiac malformations include asplenia or polysplenia, left-sided liver, right-sided stomach, gastrointestinal malrotation, and altered lung lobation. Classic heterotaxy (cardiac malformations and visceral laterality defects) has an estimated prevalence of 1:10,000 live births (Lin et al. Genet Med 2:157-172, 2000).

Genetics

Heterotaxy is a heterogeneous genetic disorder. Variants in at least 7 genes (NODAL, ZIC3, CFC1, FOXH1, LEFTY2, GDF1, and ACVR2B) involved in NODAL signaling have been proposed to cause heterotaxy or congenital heart defects (CHDs). These proteins play an essential role in establishing left-right patterning during organogenesis, including the heart and great vessels (reviewed by Hamada et al. Nat Rev Genet 3:103-113, 2002). Defects in NODAL signaling factors are also found in 5-10% of patients with isolated CHDs without heterotaxy, including tetralogy of Fallot (TOF), double outlet right ventricle (DORV), transposition of the great arteries (TGA), and cardiac septal defects (Roessler et al. Am J Hum Genet 83:18-29, 2008; Mohapatra et al. Hum Mol Genet 18:861-871, 2009). LEFTY2 (OMIM 601877) encodes a TGFβ-related secreted molecule that attenuates NODAL signaling. One missense and one nonsense variant in the LEFTY2 gene were identified in individuals with heterotaxy (Kosaki et al. Am J Hum Genet 64:712-721, 1999). Both individuals inherited the mutant allele from an apparently unaffected parent, indicating incomplete penetrance.

Clinical Sensitivity - Sequencing with CNV PGxome

Variants in the LEFTY2 gene are estimated to cause ~2% of all cases of heterotaxy (Kosaki et al. Am J Hum Genet 64:712-721, 1999).

Testing Strategy

This test provides full coverage of all coding exons of the LEFTY2 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

All patients with heterotaxic phenotypes are candidates for this test.

Gene

Official Gene Symbol OMIM ID
LEFTY2 601877
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
Heterotaxy, Visceral, 2, Autosomal 605376

Citations

  • Hamada, H., et.al. (2002). "Establishment of vertebrate left-right asymmetry." Nat Rev Genet 3(2): 103-13. PubMed ID: 11836504
  • Kosaki et al. (1999)  Characterization and mutation analysis of human LEFTY A and LEFTY B, homologues of murine genes implicated in left-right axis development.  Am J Hum Genet 64(3):712-721. PubMed ID: 10053005
  • Kosaki et al. (1999)  Characterization and mutation analysis of human LEFTY A and LEFTY B, homologues of murine genes implicated in left-right axis development.  Am J Hum Genet 64(3):712-721. PubMed ID: 10053005
  • Lin AE, Ticho BS, Houde K, Westgate MN, Holmes LB. 2000. Heterotaxy: associated conditions and hospital-based prevalence in newborns. Genet. Med. 2: 157–172. PubMed ID: 11256661
  • Mohapatra, B., et.al. (2009). "Identification and functional characterization of NODAL rare variants in heterotaxy and isolated cardiovascular malformations." Hum Mol Genet 18(5): 861-71. PubMed ID: 19064609
  • Roessler, E., et.al. (2008). "Reduced NODAL signaling strength via mutation of several pathway members including FOXH1 is linked to human heart defects and holoprosencephaly." Am J Hum Genet 83(1): 18-29. PubMed ID: 18538293

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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