X-Linked Lissencephaly-2 via the ARX 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
10003 ARX 81404 81404,81403 $640 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
10003ARX81404 81403, 81404 $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.

A 25% additional charge will be applied to STAT orders. View STAT turnaround times here.

Targeted Testing

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

Turnaround Time

18 days on average

EMAIL CONTACTS

Genetic Counselors

Geneticist

Clinical Features and Genetics

Clinical Features

Lissencephalies are a group of cerebral malformations due to an arrest of neuronal migration during embryogenesis. They are characterized by simplification or absence of the brain convolutions, resulting in a smooth appearance. Lissencephalies are characterized by intellectual disability and seizures. Additional features include microcephaly, subtle dysmorphic features, failure to thrive, difficulty feeding and swallowing, malformations of the digits, muscle spasms, myoclonic jerks, and poor social interactions (Leventer et al. 2001. PubMed ID: 11502906; Wallerstein et al. 2008. PubMed ID: 18462864).

Lissencephalies are clinically and genetically heterogeneous. Several forms are recognized. They are distinguished by the clinical features and causative genes. Lissencephaly X-linded 2 can be distinguished by ambiguous genitalia, hypothalamic dysfunction, hypotonia, hyperreflexia, intractable epilepsy, agenesis of the corpus callosum, and thickened cortex (Bonneau et al. 2002. PubMed ID: 11891829; Kato et al. 2004. PubMed ID: 1472291; Dobyns et al. 1999. PubMed ID: 10494089; Marsh et al. 2009. PubMed ID: 19439424). Onset is neonatal in males, and death occurs early. Female carriers may be unaffected or mildly affected (Marsh et al. 2009. PubMed ID: 19439424).

Genetics

Lissencephaly X-linked 2 is caused by pathogenic variants in the ARX gene (Kitamura et al. 2002. PubMed ID: 12379852; Bonneau et al. 2002. PubMed ID: 11891829; Kato et al. 2004. PubMed ID: 14722918). To date, ~ 30 pathogenic variants have been implicated in the disease. Two thirds of the variants are truncating and include nonsense, splice site, small frameshift deletions or insertions, and large deletions. The remaining variants are missense (Human Gene Mutation Database).

ARX encodes the Aristaless-related homeobox transcription factor, which plays a crucial role in cerebral development and patterning (Bienvenu et al. 2002. PubMed ID: 11971879).

Clinical Sensitivity - Sequencing with CNV PG-Select

Pathogenic variants in the ARX gene have been detected in about 4% of patients from a large cohort of children with lissencephaly (Di Donato et al. 2018. PubMed ID: 29671837).

Testing Strategy

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

Indications for Test

Candidates for this test are patients with X-linked lissencephaly with ambiguous genitalia.

Gene

Official Gene Symbol OMIM ID
ARX 300382
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Citations

  • Bienvenu et al. 2002. PubMed ID: 11971879
  • Bonneau et al. 2002. PubMed ID: 11891829
  • Di Donato et al. 2018. PubMed ID: 29671837
  • Dobyns et al. 1999. PubMed ID: 10494089
  • Human Gene Mutation Database (Bio-base).
  • Kato et al. 2004. PubMed ID: 14722918
  • Kitamura et al. 2002. PubMed ID: 12379852
  • Leventer et al. 2001. PubMed ID: 11502906
  • Marsh et al. 2009. PubMed ID: 19439424
  • Wallerstein et al. 2008. PubMed ID: 18462864

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.

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 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.

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