Andersen-Tawil Syndrome/Long QT Syndrome via the KCNJ2 Gene
Summary and Pricing
Test MethodExome Sequencing with CNV Detection
|Test Code||Test Copy Genes||Test CPT Code||Gene CPT Codes Copy CPT Codes||Base Price|
|9163||KCNJ2||81403||81403,81479||$890||Order Options and Pricing|
|Test Code||Test Copy Genes||Test CPT Code||Gene CPT Codes Copy CPT Code||Base Price|
|9163||KCNJ2||81403||81403(x1), 81479(x1)||$890||Order Options and Pricing|
- Chun-An Chen, PhD
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. If the Sanger option is selected, CNV detection may be ordered through Test #600.
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).
The Sanger Sequencing method for this test is NY State approved.For Sanger Sequencing click here.
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.
For ordering sequencing of targeted known variants, go to our Targeted Variants page.
- Chun-An Chen, PhD
Clinical Features and Genetics
Anderson-Tawil syndrome (ATS), also called Andersen syndrome and Long QT syndrome 7, is a disorder that causes episodes of muscle weakness (periodic paralysis), changes in heart rhythm (arrhythmia), prolonged QT interval and dysmorphic features (Davies et al. 2005).
KCNJ2, encoding the inward rectifier potassium channel 2 protein (Kir2.1), is an important determinant of resting membrane potential and cell excitability (Plaster et al 2001). KCNJ2 is the only gene known to cause Anderson-Tawil syndrome.
Clinical Sensitivity - Sequencing with CNV PGxome
60% of Andersen–Tawil syndrome patients have a detectable pathogenic KCNJ2 mutation, while the genetic cause in the other 40% remains elusive (Kukla P 2014). Analytical sensitivity should be high because the majority of mutations reported are detectable by sequencing.
Approximately 5% of ATS cases are caused by a gross deletion or duplication (Human Gene Mutation Database).
This test provides full coverage of all coding exons of the KCNJ2 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
All patients with symptoms suggestive of Long QT syndrome are candidates for this test.
|Official Gene Symbol||OMIM ID|
|Long QT Syndrome via the KCNJ5 Gene|
|Long QT Syndrome via the SCN4B Gene|
- Cerrone M. et al. 2012. Circulation. Cardiovascular genetics. 5: 581-90. PubMed ID: 23074337
- Davies NP, Imbrici P, Fialho D, Herd C, Bilsland LG, Weber A, Mueller R, Hilton-Jones D, Ealing J, Boothman BR, Giunti P, Parsons LM, Thomas M, Manzur AY, Jurkat-Rott K, Lehmann-Horn F, Chinnery PF, Rose M, Kullmann DM, Hanna MG. 2005. Andersen-Tawil syndrome: new potassium channel mutations and possible phenotypic variation. Neurology 65: 1083–1089. PubMed ID: 16217063
- Human Gene Mutation Database (Bio-base).
- Human Gene Mutation Database (Bio-base).
- Kukla P, Biernacka EK, Baranchuk A, Jastrzebski M, Jagodzinska M. 2014. Electrocardiogram in Andersen-Tawil syndrome. New electrocardiographic criteria for diagnosis of type-1 Andersen-Tawil syndrome. Curr Cardiol Rev 10: 222–228. PubMed ID: 24827800
- Plaster NM. et al. 2001. Cell. 105: 511-9. PubMed ID: 11371347
- Priori et al. 2004. PubMed ID: 15367556
- Schwartz et al. 2001. PubMed ID: 11136691
- Tristani-Firouzi M, Jensen JL, Donaldson MR, Sansone V, Meola G, Hahn A, Bendahhou S, Kwiecinski H, Fidzianska A, Plaster N, Fu Y-H, Ptacek LJ, Tawil R. 2002. Functional and clinical characterization of KCNJ2 mutations associated with LQT7 (Andersen syndrome). Journal of Clinical Investigation 110: 381–388. PubMed ID: 12163457
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.
- 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.
PGxome (Exome) Sequencing Panel
PGnome (Genome) Sequencing Panel
ORDER OPTIONSView 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.