Neuronal Ceroid Lipofuscinosis 10 via the CTSD 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 | |
---|---|---|---|---|---|
4131 | CTSD | 81479 | 81479,81479 | $990 | Order Options and Pricing |
Pricing Comments
Testing run on PG-select capture probes includes CNV analysis for the gene(s) on the panel but does not permit the optional add on of exome-wide CNV analysis. Any of the NGS platforms allow reflex to other clinically relevant genes, up to whole exome or whole genome sequencing depending upon the base platform selected for the initial test.
An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.
This test is also offered via a custom panel (click here) on our exome or genome backbone which permits the optional add on of exome-wide CNV or genome-wide SV analysis.
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
The neuronal ceroid lipofuscinoses (NCLs) are inherited neurodegenerative lysosomal storage disorders caused by the accumulation of ceroid and lipofuscin in various cell types, mainly cells of the cerebral cortex, cerebellar cortex, and retina (Dyken et al. 1988; Williams and Mole 2012). Characteristic features at onset include clumsiness; deterioration of vision and psychomotor functions; seizures and behavioral changes. Progression of clinical features results ultimately in total disability, blindness and premature death. Although NCL affects primarily children, age of onset of symptoms varies from infancy to adulthood. The incidence of NCL is variable and ranges from 1.3 to 7 per 100,000 (Mole and Williams 2013). However, it is more common in the northern European populations, particularly Finland where the incidence may reach 1 in 12,500 individuals and a carrier frequency of 1 in 70 (Rider and Rider 1988). NCLs are clinically and genetically heterogeneous. A nomenclature and classification based both on the age of onset of symptoms and the disease-causing gene has been recently developed, which classifies NCLs into thirteen subtypes (CLN1-8, 10-14) (Williams and Mole 2012). The causative gene for the CLN9 phenotype has not been identified yet (Schulz et al. 2004).
Of note, NCLs were previously known as Batten disease. However, in recent nomenclature, Batten disease only applies to NCL caused by mutations in CLN3.
CLN10 has been associated with congenital onset, rapid progression and death during the first few weeks of life. Symptoms at onset include post-natal respiratory insufficiency, status epilepticus and microcephaly (Barohn et al. 1992). Previously, juvenile onset was considered to be an atypical form of CLN10 because only one case was reported in the literature (Steinfeld 2006). In this case, symptoms started during the early-school age, and included ataxia, retinitis pigmentosa and cerebral and cerebellar atrophy. Progressive cognitive and motor dysfunction developed later. Recently, two consanguineous families with a history of CLN10, similar features, and sensory axonal neuropathy were reported (Hersheson et al. 2014). In these two families symptoms started at age 8 and 15 years.
Genetics
Most CLNs are inherited in an autosomal recessive manner. Thirteen genes have been implicated in the disorder: PPT1, TPP1, CLN3, CLN5, CLN6, MFSD8, CLN8, CTSD, DNAJC5, CTSF, ATP13A2, GRN, and KCTD7 (Mole and Williams 2013). CLN10 is caused by compound heterozygous or homozygous pathogenic variants in the CTSD gene (Siintola et al. 2006; Steinfeld et al. 2006). Ten different pathogenic variants have been reported in various ethnic populations, including families from Somalia, Germany, the United States, and Pakistan. Eight of the variants are missense; the two remaining are expected to result in a truncated protein. No large pathogenic deletions have been reported to date (Human Gene Mutation Database).
Pathogenic variants in CTSD appear to be a rare cause of NCL. They account for about 1% of patients with a clinical diagnosis of the disorder (Santorell et al. 2013).
The CTSD gene encodes cathespsin D (CatD), a ubiquitously expressed lysosomal protease that is involved in several cellular functions, including proteolytic degradation (Baldwin et al. 1993). Complete or near complete deficiency of CatD activity causes a congenital and severe phenotype (Siintola et al. 2006; Fritchie et al. 2009); while a partial deficiency results in a juvenile phenotype (Steinfeld et al. 2006; Hersheson et al. 2014).
Clinical Sensitivity - Sequencing with CNV PG-Select
Pathogenic variants in CTSD appear to be a rare cause of NCL. They account for about 1% of patients with a clinical diagnosis of the disorder (Santorelli et al. 2013).
Testing Strategy
This test provides full coverage of all coding exons of the CTSD gene, plus ~10 bases of flanking noncoding DNA. We define full coverage as >20X NGS reads or Sanger sequencing.
Indications for Test
Candidates for this test are patients with a clinical diagnosis suggestive of neuronal ceroid lipofuscinosis. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in CTSD.
Gene
Official Gene Symbol | OMIM ID |
---|---|
CTSD | 116840 |
Inheritance | Abbreviation |
---|---|
Autosomal Dominant | AD |
Autosomal Recessive | AR |
X-Linked | XL |
Mitochondrial | MT |
Disease
Name | Inheritance | OMIM ID |
---|---|---|
Ceroid Lipofuscinosis Neuronal 10 | AR | 610127 |
Related Tests
Citations
- Baldwin ET. et al. 1993. Proceedings of the National Academy of Sciences of the United States of America. 90: 6796-800 PubMed ID: 8393577
- Barohn RJ et al. 1992. Pediatric neurology. 8: 54–59. PubMed ID: 1558577
- Dyken P.R. 1988. American journal of medical genetics. Supplement. 5: 69-84. PubMed ID: 3146331
- Fritchie K. et al. 2009. Acta neuropathologica. 117: 201–8. PubMed ID: 18762956
- Hersheson J. et al. 2014. Neurology. 83: 1873-5. PubMed ID: 25298308
- Human Gene Mutation Database (Bio-base).
- Mole S.E., Williams R.E. 2013. Neuronal Ceroid-Lipofuscinoses. 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: 20301601
- Rider J.A., Rider D.L. 1988. American journal of medical genetics. Supplement. 5: 21-6. PubMed ID: 3146319
- Santorelli FM. et al. 2013. Orphanet journal of rare diseases. 8: 19. PubMed ID: 23374165
- Schulz A. et al. 2004. Annals of neurology. 56: 342-50. PubMed ID: 15349861
- Siintola E. et al. 2006. Brain : a journal of neurology. 129: 1438-45. PubMed ID: 16670177
- Steinfeld R. et al. 2006. American journal of human genetics. 78: 988-98 PubMed ID: 16685649
- Williams R.E., Mole S.E. 2012. Neurology. 79: 183-91. PubMed ID: 22778232
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
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
ORDER OPTIONS
View Ordering Instructions1) Select Test Type
2) Select Additional Test Options
No Additional Test Options are available for this test.