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Epilespy, Autosomal Dominant Lateral Temporal, via the LGI1 Gene

Summary and Pricing

Test Method

Sequencing and CNV Detection via NextGen Sequencing using PG-Select Capture Probes
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
7037 LGI1 81479 81479,81479 $640 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
7037LGI181479 81479,81479 $640 Order Options and Pricing

Pricing Comments

This test is also offered via our exome backbone with CNV detection (click here). The exome-based test may be higher priced, but permits reflex to the entire exome or to any other set of clinically relevant genes.

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

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

  • Eric Bend, PhD

Clinical Features and Genetics

Clinical Features

Autosomal Dominant Lateral Temporal Epilepsy (ADLTE), also named Autosomal Dominant Partial Epilepsy with Auditory Features (ADPEAF), is an idiopathic focal epilepsy syndrome characterized by focal seizures initiated in the temporal lobe with prominent auditory features or aphasia. The most common auditory features are simple unformed sounds such as humming, buzzing, or ringing; less common forms are distortions or complex sounds. Most patients have secondarily generalized seizures, usually accompanied by simple partial and complex partial seizures. MRI is normal and Interictal EEG is often normal too. However, focal epileptiform abnormalities (usually localized to the temporal region) can be found in up to two thirds of patients. Age of onset varies from adolescence to the second decade of life. Seizures are well controlled by antiepileptic treatment, but recur after drug discontinuation. The prognosis is favorable in most cases (Michelucci et al. 2003; Ottman et al. 2004; Di Bonaventura et al. 2011).

Genetics

Autosomal Dominant Lateral Temporal Epilepsy is inherited in an autosomal dominant manner. Pathogenic variants in LGI1 cause this type of epilepsy (Wilmshurst et al. 2015). The majority of pathogenic variants reported in LGI1 gene are missense. Others include nonsense, splicing, small deletions/duplications, as well as large deletions compassing the LGI1 locus (Michelucci et al. 2003; Lee et al. 2014; Fanciulli et al. 2012). Uncommonly, low penetrance can be observed due to the effect on protein secretion by certain pathogenic LGI1 variants (Di Bonaventura et al. 2011). Pathogenic variants in the LGI1 gene can occur in both familial and sporadic cases. De novo pathogenic variants have been reported, but the proportion is very low, around 2% in affected families (Nobile et al. 2009).

The leucine-rich glioma-inactivated 1 (LGI1) gene encodes a secreted protein. This protein is linked to human seizures of both genetic and autoimmune aetiology. A transgenic mouse model revealed that the LGI1 protein is required from embryogenesis to adulthood to maintain proper circuit functioning (Boillot et al. 2014). However, it remains unclear whether secreted and/or cytoplasmic LGI1 protein is involved in the circuit hyperexcitability that triggers seizures.

Clinical Sensitivity - Sequencing with CNV PG-Select

Pathogenic variants in the LGI1 gene have been reported in up to 50% of families with Autosomal Dominant Lateral Temporal Epilepsy (Berghuis et al. 2013).

Testing Strategy

This test provides full coverage of all coding exons of the LGI1 gene, plus ~10 bases of flanking noncoding DNA. We define full coverage as >20X NGS reads or Sanger sequencing.

Indications for Test

Testing of LGI1 is considered for patients who are suspected to have Autosomal Dominant Lateral Temporal Epilepsy.

Gene

Official Gene Symbol OMIM ID
LGI1 604619
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
Epilepsy, Lateral Temporal Lobe, Autosomal Dominant AD 600512

Citations

  • Berghuis B. et al. 2013. Epilepsy & Behavior : E&B. 28: 41-6. PubMed ID: 23651915
  • Boillot M. et al. 2014. Brain : a Journal of Neurology. 137: 2984-96. PubMed ID: 25234641
  • Di Bonaventura C. et al. 2011. Epilepsia. 52: 1258-64. PubMed ID: 21504429
  • Fanciulli M. et al. 2012. Neurology. 78: 1299-303. PubMed ID: 22496201
  • Lee MK. et al. 2014. Seizure. 23: 69-73. PubMed ID: 24177143
  • Michelucci R. et al. 2003. Epilepsia. 44: 1289-97. PubMed ID: 14510822
  • Nobile C. et al. 2009. Human Mutation. 30: 530-6. PubMed ID: 19191227
  • Ottman R. et al. 2004. Neurology. 62: 1120-6. PubMed ID: 15079011
  • Wilmshurst J.M. et al. 2015. Epilepsia. 56: 1185-97. PubMed ID: 26122601

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

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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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