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Early-Onset Ataxia with Oculomotor Apraxia Type 1 via the APTX 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
11091 APTX 81405 81405,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
11091APTX81405 81405(x1), 81479(x1) $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. If the Sanger option is selected, CNV detection may be ordered through Test #600.

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

  • Dana Talsness, PhD

Clinical Features and Genetics

Clinical Features

Early-onset ataxia with oculomotor apraxia type 1 (AOA1) is an autosomal recessive cerebellar ataxia characterized by oculomotor apraxia (limitation of ocular movements on command), peripheral neuropathy, and hypoalbuminemia. Usually AOA1 occurs before 2 years of age with relatively rapid progression and severe dystonia. Oculomotor apraxia is a major clinical feature of AOA1 (Moreira et al. 2001; Ito et al. 2005).

Genetics

AOA1 is an autosomal recessive disorder, caused by mutations in the APTX gene located on chromosome 9 (Ito et al. 2005). APTX encodes the aprataxin protein, which is involved in DNA single-strand-break repair (SSBR) (Mosesso et al. 2005; Hirano et al. 2007). It has been reported that loss of aprataxin function leads to accumulation of SSBs, which results in human neurodegenerative disorders such as AOA1 (Tada et al. 2010). Genotype-phenotype correlation studies indicate that mild mutations such as missense mutations in APTX result in later onset, and severe mutations such as nonsense or frame shift mutations result in early onset (Nouri et al. 2012). However, a remarkably severe disease phenotype was associated with the missense mutation c.593C>T (p.Ala198Val) (Le Ber et al. 2003). Exon 6 has been reported as a mutational hot spot in the APTX gene (Nouri et al. 2012). So far, about 30 causative mutations have been reported APTX, which include missense, nonsense, splicing, small deletions, small insertions and gross deletions (Human Gene Mutation Database).

Clinical Sensitivity - Sequencing with CNV PGxome

Castellotti et al. identified APTX mutations in 6% of their ataxic patients (13 out of 204) (Castellotti et al. 2011).

Testing Strategy

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

All patients with symptoms suggestive of early-onset ataxia with oculomotor apraxia type 1 are candidates. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in APTX.

Gene

Official Gene Symbol OMIM ID
APTX 606350
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
Adult Onset Ataxia With Oculomotor Apraxia AR 208920

Citations

  • Castellotti B. et al. 2011. Neurogenetics. 12: 193-201. PubMed ID: 21465257
  • Hirano M. et al. 2007. Annals of Neurology. 61: 162-74. PubMed ID: 17315206
  • Human Gene Mutation Database (Bio-base).
  • Ito A. et al. 2005. Pediatric Neurology. 33: 53-6. PubMed ID: 15876520
  • Le Ber I, Moreira MC, Rivaud-Péchoux S, Chamayou C, Ochsner F, Kuntzer T, Tardieu M, Saïd G, Habert MO, Demarquay G, Tannier C, Beis JM, Brice A, Koenig M, Dürr A.. 2003. Cerebellar ataxia with oculomotor apraxia type 1: clinical and genetic studies. Brain 126: 2761–2772. PubMed ID: 14506070
  • Moreira MC, Barbot C, Tachi N, Kozuka N, Mendonça P, Barros J, Coutinho P, Sequeiros J, Koenig M. 2001. Homozygosity mapping of Portuguese and Japanese forms of ataxia-oculomotor apraxia to 9p13, and evidence for genetic heterogeneity. The American Journal of Human Genetics 68: 501–508. PubMed ID: 11170899
  • Mosesso P. et al. 2005. Cellular and Molecular Life Sciences : Cmls. 62: 485-91. PubMed ID: 15719174
  • Nouri N, Nouri N, Aryani O, Kamalidehghan B, Sedghi M, Houshmand M. 2012. A novel mutation in the aprataxin (APTX) gene in an Iranian individual suffering early-onset ataxia with oculomotor apraxia type 1 (AOA1) disease. Iranian biomedical journal 16: 223. PubMed ID: 23183622
  • Tada M. et al. 2010. Advances in Experimental Medicine and Biology. 685: 21-33. PubMed ID: 20687492

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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