Andermann Syndrome via the SLC12A6 Gene
Summary and Pricing 
Test Method
Sequencing and CNV Detection via NextGen Sequencing using PG-Select Capture Probes| Test Code | Test Copy Genes | Test CPT Code | Gene CPT Codes Copy CPT Code | Base Price | |
|---|---|---|---|---|---|
| 4947 | SLC12A6 | 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
Andermann Syndrome or Hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC) is a neurodevelopmental and neurodegenerative disorder associated with dysmorphic features. The disorder is characterized by severe progressive sensorimotor neuropathy with resulting hypotonia, areflexia, and amyotrophy and variable degrees of dysgenesis of the corpus callosum. Mild-to-severe intellectual disability and "psychotic episodes" during adolescence are observed. Sensory modalities are moderately to severely affected beginning in infancy. The average age of onset of walking is 3.8 years; the average age of loss of walking is 13.8 years while the average age of death is 33 years (Dupré et al. 2003).
Genetics
Andermann syndrome has a high prevalence of 1 in 2000 newborns in the French Canadian population in the Charlevoix and Saguenay-Lac-Saint-Jean region of Quebec (Uyanik et al. 2006) and is inherited as an autosomal recessive disorder.
The SLC12A6 gene is the only gene with mutations known to be causative for Andermann syndrome. The SLC12A6 gene codes for a potassium-chloride cotransporter which is involved in moving charged potassium (K) and chloride (Cl) ions across the cell membrane. While the specific function of the K-Cl cotransporter produced from the SLC12A6 gene is unknown, it seems to be critical for the development and maintenance of nerve tissue. Most reported causative mutations in SLC12A6 are truncating and missense mutations (Uyanik et al. 2006; Howard et al. 2002). The lack of functional protein normally produced from the SLC12A6 gene is believed to interfere with the development of the corpus callosum and maintenance of the nerves that transmit signals needed for movement and sensation, resulting in the signs and symptoms of Andermann syndrome.
Clinical Sensitivity - Sequencing with CNV PG-Select
Molecular genetic testing by sequencing of SLC12A6 detects more than 90% of disease-causing mutations. In particular, the c.2436delG mutation is the one found in almost all (>99%) individuals of French-Canadian descent and has a clinical sensitivity of 100%.
Testing Strategy
This test provides full coverage of all coding exons of the SLC12A6 gene, plus ~10 bases of flanking noncoding DNA. We define full coverage as >20X NGS reads or Sanger sequencing.
Indications for Test
Individuals with clinical manifestations including severe progressive sensorimotor neuropathy with resulting hypotonia, areflexia, and amyotrophy or those that have a variable degree of dysgenesis of the corpus callosum as determined by MRI would be candidates for SLC12A6 testing (Dupré et al. 2003). This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in SLC12A.
Individuals with clinical manifestations including severe progressive sensorimotor neuropathy with resulting hypotonia, areflexia, and amyotrophy or those that have a variable degree of dysgenesis of the corpus callosum as determined by MRI would be candidates for SLC12A6 testing (Dupré et al. 2003). This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in SLC12A.
Gene
| Official Gene Symbol | OMIM ID |
|---|---|
| SLC12A6 | 604878 |
| Inheritance | Abbreviation |
|---|---|
| Autosomal Dominant | AD |
| Autosomal Recessive | AR |
| X-Linked | XL |
| Mitochondrial | MT |
Disease
| Name | Inheritance | OMIM ID |
|---|---|---|
| Andermann Syndrome | AR | 218000 |
Citations
- Dupré N, Howard HC, Mathieu J, Karpati G, Vanasse M, Bouchard J-P, Carpenter S, Rouleau GA. 2003. Hereditary motor and sensory neuropathy with agenesis of the corpus callosum. Ann. Neurol. 54: 9–18.
PubMed ID: 12838516 - Howard HC, Mount DB, Rochefort D, Byun N, Dupré N, Lu J, Fan X, Song L, Rivière J-B, Prévost C, Horst J, Simonati A, et al. 2002. The K-Cl cotransporter KCC3 is mutant in a severe peripheral neuropathy associated with agenesis of the corpus callosum. Nat. Genet. 32: 384–392. PubMed ID: 12368912
- Uyanik G, Elcioglu N, Penzien J, Gross C, Yilmaz Y, Olmez A, Demir E, Wahl D, Scheglmann K, Winner B, Bogdahn U, Topaloglu H, et al. 2006. Novel truncating and missense mutations of the KCC3 gene associated with Andermann syndrome. Neurology 66: 1044–1048. PubMed ID: 16606917
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
Specimen Requirements and Shipping Details
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ORDER OPTIONS
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