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Canavan Disease (Aspartoacylase Deficiency) via the ASPA 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
9533 ASPA 81479 81479,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
9533ASPA81479 81479,81479 $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

  • McKenna Kyriss, PhD

Clinical Features and Genetics

Clinical Features

Canavan disease (Aspartoacylase deficiency) is a neonatal/infantile disease characterized by macrocephaly, lack of head control, hyperextension of legs and flexion of arms, blindness and severe developmental delays usually noted by age three to five months. As children get older, hypotonia becomes severe and failure to achieve independent sitting, ambulation, or speech become apparent. Hypotonia eventually changes to spasticity. Assistance with feeding becomes necessary. Life expectancy is usually into the teens. Mild/juvenile Canavan disease is characterized by mild developmental delay that can go unrecognized. Head circumference may be normal (Matalon and Michals-Matalon 2011).

Genetics

Canavan disease occurs in all ethnic groups, but has a high prevalence in individuals of Ashkenazi Jewish origin with a carrier rate of about 1 in 40. It is inherited as an autosomal recessive disorder.

The ASPA gene is the only gene with mutations known to be causative for Canavan disease. ASPA codes for the enzyme aspartoacylase, which breaks down N-acetyl-L-aspartic acid (NAA) into aspartic acid (an amino acid that is a building block of many proteins) in the brain. The cycle of production and breakdown of NAA appears to be critical for maintaining the brain's white matter, which consists of nerve fibers covered by myelin, that insulates and protects nerves. Mutations in the ASPA gene reduce or eliminate the activity of aspartoacylase, which prevents the normal breakdown of NAA. Buildup of NAA also leads to progressive destruction of existing myelin around nerve cells. Nerve fibers without this protective covering malfunction and die, damaging the brain and causing the serious signs and symptoms of Canavan disease.

More than 55 mutations in the ASPA gene are known to cause Canavan disease. Two specific mutations cause most cases of the disease in the Ashkenazi Jews; Glu285Ala or E285A and Tyr231Ter or Y231X. The Ala305Glu or A305E mutation is common in individuals who are not of Ashkenazi Jewish origin.

Clinical Sensitivity - Sequencing with CNV PGxome

Molecular genetic testing by sequencing of ASPA will detect 87% of disease-causing mutations in individuals of Non-Ashkenazi Jewish origin. The founder mutations in individuals of Ashkenazi Jewish ancestry will also be detected.

Testing Strategy

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

Infants/neonates with white matter disease seen on neuroimaging and elevated N-acetylaspartic acid (NAA) in the urine should be considered for ASPA gene testing. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in ASPA.

Gene

Official Gene Symbol OMIM ID
ASPA 608034
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
Spongy Degeneration Of Central Nervous System AR 271900

Citations

  • Matalon R, Michals-Matalon K. 2011. Canavan Disease. In: Pagon RA, Adam MP, Bird TD, Dolan CR, Fong C-T, and Stephens K, editors. GeneReviews™, Seattle (WA): University of Washington, Seattle. PubMed ID: 20301412

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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