Epilepsy: Unverricht-Lundborg Disease via the CSTB 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 | |
---|---|---|---|---|---|
9095 | CSTB | 81189 | 81189,81479 | $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
Unverricht-Lundborg disease, also known as progressive myoclonic epilepsy 1A, and Myoclonic epilepsy of Unverricht and Lundborg, is a rare hereditary neurodegenerative disorder characterized by onset of neurodegeneration between 6 and 13 years of age and generalized myoclonic seizures. Onset peaks at around age 12-13. Other neurological manifestations such as ataxia are rare. Cognitive impairment varies from absent to moderate. Treatment is available (Crespel et al. 2016. PubMed ID: 27582036).
Genetics
Unverricht-Lundborg disease is inherited in an autosomal recessive manner and is caused by pathogenic variants in CSTB, which encodes cystatin B, a member of the superfamily of cysteine protease inhibitors.
CSTB pathogenic variants include missense, nonsense, splicing, small frameshift deletions and small indels (Human Gene Mutation Database). The most common pathogenic variant is an unstable expansion of a 12-nucleotide (dodecamer) repeat 5'-CCC-CGC-CCC-GCG-3' in the promoter region. This expansion accounts for approximately 90% of the patients worldwide and 99% of the cases in Finland, most of them in a homozygous state (Hyppönen et al. 2015. PubMed ID: 25770194; Crespel et al. 2016. PubMed ID: 27582036). Large deletions and duplications involving CSTB have not been reported.
Clinical Sensitivity - Sequencing with CNV PG-Select
Sequencing will not identify the most common dodecamer repeat expansion in the CSTB gene (90% of cases). Therefore, the sensitivity of this test is expected to be low (10% of cases).
To date, no large deletions/duplications have been reported involving CSTB.
Testing Strategy
This test provides full coverage of all coding exons of the CSTB gene, plus ~10 bases of flanking noncoding DNA. We define full coverage as >20X NGS reads or Sanger sequencing.
Indications for Test
This test is recommended for cases suspected to have Unverricht-Lundborg disease (Crespel et al. 2016. PubMed ID: 27582036). This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in CSTB.
This test is recommended for cases suspected to have Unverricht-Lundborg disease (Crespel et al. 2016. PubMed ID: 27582036). This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in CSTB.
Gene
Official Gene Symbol | OMIM ID |
---|---|
CSTB | 601145 |
Inheritance | Abbreviation |
---|---|
Autosomal Dominant | AD |
Autosomal Recessive | AR |
X-Linked | XL |
Mitochondrial | MT |
Disease
Name | Inheritance | OMIM ID |
---|---|---|
Unverricht-Lundborg Syndrome | AR | 254800 |
Citations 
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.