DNA icon

Leukoencephalopathy, Progressive, with Ovarian Failure via the AARS2 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
11893 AARS2 81479 81479,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
11893AARS281479 81479,81479 $890 Order Options and Pricing

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).

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

  • Li Fan, MD, PhD, FCCMG, FACMG

Clinical Features and Genetics

Clinical Features

AARS2-related Leukoencephalopathy is one of the most common adult onset leukoencephalopathies and is characterized by progressive leukoencephalopathy with ovarian failure (Dallabona et al. 2014. PubMed ID: 24808023; Lynch et al. 2017. PubMed ID: 28334938; Lynch et al. 2018. PubMed ID: 30467211; Lakshmanan et al. 2017. PubMed ID: 28243630; Srivastava et al. 2019. PubMed ID: 31099476). Early symptoms may include developmental delay in childhood. Onset of the disorder is usually in young adulthood. The major features include cerebellar ataxia with nystagmus, dysarthria, tremor, upper motor neuron signs. In certain cases, patients present other neurological symptom such as cognitive deterioration, dementia and psychosis. Brain MRI shows slightly asymmetric abnormal T2 hyperintense signal in the frontoparietal and periventricular white matter, with white matter rarefaction, involvement of the corpus callosum and pyramidal tracts and punctate areas of restricted diffusion. Males and females are about equally affected. Ovarian failure was present in all known female cases. AARS2-related Leukoencephalopathy is a rare disease with prevalence of roughly 1 per 100,000.

In addition, pathogenic variants in AARS2 are also causative for combined oxidative phosphorylation deficiency 8 . Major symptoms include severe infantile hypertrophic mitochondrial cardiomyopathy, pulmonary hypoplasia, and early-onset brain disease. Other features include failure to thrive. If both the heart and brain are involved, the prognosis is poor (Dallabona et al. 2014. PubMed ID: 24808023; Kamps et al. 2018. PubMed ID: 29440775).

As both leukoencephalopathy and combined oxidative phosphorylation deficiency can be caused by defects in a number of genes with variable and overlapping presentations, they can be difficult to diagnose by clinical manifestation and image studies only. An accurate molecular diagnosis is critical for treatment, prognosis, prediction of recurrence risk, as well as future family plans.

Genetics

AARS2-related disorders are inherited in an autosomal recessive manner. Pathogenic variants in AARS2 include missense, nonsense, splicing, and small deletion/duplications (mostly frameshift). No large deletions and duplications have been reported in the AARS2 locus (Dallabona et al. 2014. PubMed ID: 24808023; Lynch et al. 2017. PubMed ID: 28334938; Lynch et al. 2018. PubMed ID: 30467211; Lakshmanan et al. 2017. PubMed ID: 28243630; Human Gene Mutation Database). No de novo pathogenic variants have been documented in this gene. The vast majority of variants are missense. The most frequently reported pathogenic variant in AARS2, p.Arg592Trp, is located in the alanyl-tRNA synthetase core domain with allele frequency of 0.04% in the non-Finnish European population (gnomAD database).  

AARS2 encodes a mitochondrial aminoacyl tRNA synthetase, which is responsible for the charging of tRNA-Ala with alanine during mitochondrial translation. A mouse model demonstrated that tRNA proofreading is essential in mammalian mitochondria, and cannot be overcome by other quality control mechanisms (Hilander et al. 2018. PubMed ID: 29228266). AARS2 has been cited as a conditional essential gene for growth of human tissue culture cells (Online Gene Essentiality, ogee.medgenius.info). 

Clinical Sensitivity - Sequencing with CNV PGxome

Clinical sensitivity of AARS2 gene in a large cohort of patients with Leukoencephalopathy, progressive, with ovarian failure relevant phenotypes is unavailable in the literature because most of studies are case reports. Analytical sensitivity is expected to be high as all reported pathogenic variants are detectable by sequencing. AARS2-related Leukoencephalopathy is one of the most common adult onset leukoencephalopathies.

Testing Strategy

This test is performed using Next-Gen sequencing with additional Sanger sequencing as necessary.

This test provides full coverage of all coding exons of the AARS2 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

AARS2 sequencing is recommended for people suspected to have AARS2-related progressive leukoencephalopathy with ovarian failure or combined oxidative phosphorylation deficiency 8. Targeted testing is indicated for family members of patients who have a known pathogenic variant in AARS2. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in AARS2.

Gene

Official Gene Symbol OMIM ID
AARS2 612035
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Citations

  • Dallabona et al. 2014. PubMed ID: 24808023
  • Genome Aggregation Database.
  • Hilander et al. 2018. PubMed ID: 29228266
  • Human Gene Mutation Database (Biobase).
  • Kamps et al. 2018. PubMed ID: 29440775
  • Lakshmanan et al. 2017. PubMed ID: 28243630
  • Lynch et al. 2017. PubMed ID: 28334938
  • Lynch et al. 2018. PubMed ID: 30467211
  • Srivastava et al. 2019. PubMed ID: 31099476

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

loading Loading... ×

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: $
×
Copy Text to Clipboard
×