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Galactosialidosis via the CTSA 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
CTSA 81479 81479,81479 $990
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
8121CTSA81479 81479,81479 $990 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 platform).

Click here for costs to reflex to whole PGnome (if original test is on PGnome Sequencing platform).

The Sanger Sequencing method for this test is NY State approved.

For Sanger Sequencing click here.

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.


Genetic Counselors


  • Maxime Cadieux-Dion, PhD

Clinical Features and Genetics

Clinical Features

Galactosialidosis (GSL) is a rare lysosomal storage disease characterized by combined deficiency of beta-galactosidase and neuraminidase 1, secondary to deficiency of the protective protein/cathepsin A (PPCA/CTSA). Clinically, there are three subtypes of GSL: early infantile, late infantile, and juvenile/adult. All three subtypes have characteristic features of a lysosomal storage disease including coarse facies and cherry red spots. The most severe form, early infantile, is characterized by hydrops fetalis, edema, ascites, visceromegaly, skeletal dysplasia, and early death. The late infantile form is characterized by cardiac anomalies, visceromegaly, and, in rare cases, neurological involvement. The least severe form, juvenile/adult, is characterized by ataxia, myoclonus, absence of visceromegaly, intellectual disability, growth retardation, and long survival (Caciotti et al. 2013; Prada et al. 2014; Shamseldin et al. 2015; Zhou et al. 1996).


GSL is caused by variants in the cathepsin A (CTSA) gene and is inherited in an autosomal recessive fashion. To date, about 30 pathogenic variants have been reported in CTSA, including missense, nonsense, splicing, small deletions, and small duplications (Human Gene Mutation Database). Functional studies have suggested that the severity of disease may correlate with the impact of specific variants on PPCA/CTSA protein function, with the more severe phenotype being associated with a greater reduction in the catalytic and regulatory/protective functions of the protein (Caciotti et al. 2013; Zhou et al. 1996).

Clinical Sensitivity - Sequencing with CNV PGxome

Given the rarity of GLS, no large scale studies have been performed to determine the clinical sensitivity of CTSA gene testing in these patients. However, given the characteristic biochemical features of the disorder (deficiency of beta-galactosidase and neuraminidase 1), it is expected that clinical sensitivity would be high in patients with biochemical evidence of GLS (Caciotti et al. 2013).

Testing Strategy

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

This test is appropriate for patients with clinical and biochemical findings consistent with GSL and for carrier testing in relatives of patients with known pathogenic CTSA variants.


Official Gene Symbol OMIM ID
CTSA 613111
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT


Name Inheritance OMIM ID
Galactosialidosis AR 256540


  • Caciotti A. et al. 2013. Orphanet Journal of Rare Diseases. 8: 114. PubMed ID: 23915561
  • Human Gene Mutation Database (Bio-base).
  • Prada C.E. et al. 2014. European Journal of Medical Genetics. 57: 339-44. PubMed ID: 24769197
  • Shamseldin H.E. et al. 2015. Genome Biology. 16: 116. PubMed ID: 26036949
  • Zhou X.Y. et al. 1996. Human Molecular Genetics. 5: 1977-87. PubMed ID: 8968752


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

If ordering a Duo or Trio test, the proband and all comparator samples are required to initiate testing. If we do not receive all required samples for the test ordered within 21 days, we will convert the order to the most effective testing strategy with the samples available. Prior authorization and/or billing in place may be impacted by a change in test code.

Specimen Types

Specimen Requirements and Shipping Details

PGxome (Exome) Sequencing Panel

PGnome (Genome) Sequencing Panel

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View Ordering Instructions

1) Select Test Method (Platform)

1) Select Test Type

2) Select Additional Test Options

No Additional Test Options are available for this test.

Note: acceptable specimen types are whole blood and DNA from whole blood only.
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