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Autosomal Dominant Nocturnal Frontal Lobe Epilepsy via the CHRNB2 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
8627 CHRNB2 81405 81405,81479 $640 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
8627CHRNB281405 81405,81479 $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 nocturnal frontal lobe epilepsy (ADNFLE, OMIM:600513) is a partial seizure disorder characterized by seizures that occur during non-REM sleep. Seizures in ADNFLE patients can present as repetitive limb movements, dystonic posturing, sleep walking, or sudden elevation of the body or head (Kurahashi and Hirose, GeneReviews, 2012). Seizures are brief, lasting from 5 seconds to 5 minutes, and often patients maintain consciousness throughout the attack. Frontal origin of ADNFLE seizures is revealed by ictal EEG recordings; interictal EEGs are normal. ADNFLE associated seizures are often managed with low doses of antieplieptic drugs (AEDs). ADNFLE is not generally associated with cognitive deficits or psychiatric problems, however, recent evidence suggests that a subset of ADNFLE-causing mutations may have wider neurological phenotypes (Steinlein et al. Seizure 21(2):118-123, 2012). ADNFLE can be difficult to clinically distinguish from other non-epileptic paroxysmal sleep disorders, therefore a video-polysomnography recording brain/eye/muscle activity during sleep is considered essential for diagnosis.

Genetics

ADNFLE is inherited in an autosomal dominant manner. ADNFLE is a genetically heterogeneous disorder. Mutations in the CHRNB2 gene have been reported in ~5% of individuals with a family history of ADNFLE (Ottman et al. Epilepsia 51(4):655-670, 2010). The penetrance of CHRNB2 mutations is incomplete (~70%), thus ADNFLE presentation can be variable in families (Kurahashi and Hirose, 2012).

CHRNB2 encodes a neuronally expressed beta-subunit of the nicotinic acetylcholine receptor (nAChR). The nAChRs belong to a super-family of ligand-gated ion channels. All of the reported ADNFLE-associated CHRNB2 variants are missense mutations and most are located within the transmembrane domain of the receptor. Highly conserved residues within the transmembrane domain dictate the ligand-specificity and activity of the receptor. Reported mutations in CHRNB2 are gain of function mutations, resulting in an increased sensitivity of neuronal nAChRs to the agonist acetylcholine (Phillips et al. Am J Hum Genet. 68(1):225-231, 2001). It is hypothesized that increased nAchR activity underlies the epilepsy phenotype associated with CHRNB2 mutations.

Clinical Sensitivity - Sequencing with CNV PG-Select

Mutations in CHRNB2 account for ~5% of familial ADNFLE cases (Ottman et al. Epilepsia 51(4):655-670, 2010).

Testing Strategy

This test provides full coverage of all coding exons of the CHRNB2 gene, plus ~10 bases of flanking noncoding DNA. We define full coverage as >20X NGS reads or Sanger sequencing.

Indications for Test

Candidates for CHRNB2 sequencing include patients who display symptoms of ADNFLE and who have a family history of nocturnal seizures consistent with an autosomal dominant form of inheritance.

Gene

Official Gene Symbol OMIM ID
CHRNB2 118507
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
Epilepsy, Nocturnal Frontal Lobe, Type 3 605375

Related Test

Name
Autosomal Dominant Nocturnal Frontal Lobe Epilepsy via the CHRNA4 Gene

Citations

  • Kurahashi H, Hirose S. 2012. Autosomal Dominant Nocturnal Frontal Lobe Epilepsy. In: Pagon RA, Adam MP, Ardinger HH, Bird TD, Dolan CR, Fong C-T, Smith RJ, and Stephens K, editors. GeneReviews(®), Seattle (WA): University of Washington, Seattle. PubMed ID: 20301348
  • Ottman R. et al. 2010. Epilepsia 51:655-70. PubMed ID: 20100225
  • Phillips HA, Favre I, Kirkpatrick M, Zuberi SM, Goudie D, Heron SE, Scheffer IE, Sutherland GR, Berkovic SF, Bertrand D. 2001. CHRNB2 Is the Second Acetylcholine Receptor Subunit Associated with Autosomal Dominant Nocturnal Frontal Lobe Epilepsy. The American Journal of Human Genetics 68: 225–231. PubMed ID: 11104662
  • Steinlein, O.K. et al. (2012). "Mutations in familial nocturnal frontal lobe epilepsy might be associated with distinct neurological phenotypes." Seizure 21(2):118:123. PubMed ID: 22036597

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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