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GTR Home > Tests > Hyperkalemic Periodic Paralysis Type 1

Overview

Test order codeHelp: Paramyotonia congenita(SCN4A)

Test name

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Hyperkalemic Periodic Paralysis Type 1 (SCN4A)

Purpose of the test

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This is a clinical test intended for Help: Diagnosis, Mutation Confirmation, Predictive, Prognostic

Condition

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How to order

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Please complete the requsition available on the website and ensure it is signed by the referring physician
Order URL Help: http://www.lhsc.on.ca/palm/molecular/test.html#main-content

Specimen source

Cell culture
Isolated DNA
Peripheral (whole) blood

Methodology

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Molecular Genetics
DDeletion/duplication analysis
Next-Generation (NGS)/Massively parallel sequencing (MPS)
  • Illumina MiSeq/NextSeq
XMutation scanning of select exons
Bi-directional Sanger Sequence Analysis
  • Applied Biosystems 3730 capillary sequencing instrument
CSequence analysis of the entire coding region
Next-Generation (NGS)/Massively parallel sequencing (MPS)
  • Illumina MiSeq/NextSeq

Summary of what is tested

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Clinical utility

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Establish or confirm diagnosis

Clinical validity

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Mutations in the SCN4A gene have been identified in a group of related muscular disorders, including hyperkalemic periodic paralysis (HYPP; 170500), paramyotonia congenita (PMC; 168300), a group of disorders classified as potassium-aggravated myotonia (608390), and hypokalemic periodic paralysis type 2 (HOKPP2; 613345).

Testing strategy

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All coding exons and 20 bp of flanking intronic sequence are enriched using an LHSC custom targeted hybridization protocol (Roche Nimblegen), followed by high throughput sequencing (Illumina). This chemistry and analysis pipeline provides a highly sensitive and specific detection of sequence and copy number alterations in a single assay that exceeds the previous gold standard of Sanger sequence and MLPA. Sequence variants and copy number changes are assessed and interpreted using clinically validated algorithms and commercial software (SoftGenetics: Nextgene, Geneticist Assistant, Mutation Surveyor; and Alamut Visual). All genes have >1000x mean read depth coverage, with a minimum 200x coverage at a single nucleotide resolution. Mitochondrial DNA testing is validated for heteroplasmy detection sensitivity of 2-5%. All variants interpreted as either ACMG category 1, 2, or 3 (pathogenic, likely pathogenic, VUS; PMID: 25741868) are confirmed using Sanger sequencing, MLPA, or other assays. ACMG category 4 and 5 variants (likely benign, benign) are not reported, but are available upon request. 000 Please complete the requsition available on the website and ensure it is signed by the referring physician

Test services

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  • Clinical Testing/Confirmation of Mutations Identified Previously
  • Confirmation of research findings
  • Custom Sequence Analysis
  • Custom Prenatal Testing
  • Custom mutation-specific/Carrier testing

IMPORTANT NOTE: NIH does not independently verify information submitted to the GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in the GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.