X-Linked Lissencephaly-2 via the ARX Gene
Summary and Pricing 
Test Method
Sequencing and CNV Detection via NextGen Sequencing using PG-Select Capture ProbesTest Code | Test Copy Genes | Test CPT Code | Gene CPT Codes Copy CPT Code | Base Price | |
---|---|---|---|---|---|
10003 | ARX | 81404 | 81404,81403 | $990 | 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.
Testing run on PG-Select capture probes does not include exome-wide CNV analysis. Reflex is available to PGxome or an exome-based panel, or you can use this gene list to create a custom panel (click here).
Click here for costs to reflex to whole PGxome.
Turnaround Time
3 weeks on average for standard orders or 2 weeks 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.
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.
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 |
Diseases
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.
- 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
ORDER OPTIONS
View Ordering Instructions1) 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.