Hereditary Neuropathy with Liability to Pressure Palsies (PMP22)
- GTR Test IDHelpEach Test is a specific, orderable test from a particular laboratory, and is assigned a unique GTR accession number. The format is GTR00000001.1, with a leading prefix 'GTR' followed by 8 digits, a period, then 1 or more digits representing the version. When a laboratory updates a registered test, a new version number is assigned.: GTR000319468.5
- Last updated: 2024-02-07
- Test version history
Clinical testHelpIn the U.S., clinical tests must be performed under CLIA certification. When a lab uses the same methods for a test in both clinical and research settings, the test appears as two separate GTR records. for Hereditary liability to pressure palsies
Offered by Molecular Genetics Laboratory
Overview
Test name
HelpThe name the laboratory assigns the test. Used as the default title of the page specific to the test.Hereditary Neuropathy with Liability to Pressure Palsies (PMP22) (HNPP)
This is a clinical test intended for HelpPurposes or indications for the test. Lab-provided.: Diagnosis, Mutation Confirmation
Click Indication tab for more information.
please complete the requisition provided on the website and ensure that it is signed by the referring physician
Order URL HelpLink to the laboratory webpage with information about how to order this test. Please note that clicking on this link will open a new tab in your internet browser.: http://www.lhsc.on.ca/palm/molecular.html
Specimen source
Methodology
HelpThe assay's major method category (biochemical, cytogenetic or molecular genetics); method category (i.e. enzyme assay, chromosome breakage studies, targeted mutation analysis); methodology (i.e. the name of the method used) and instruments used when performing this test.- Molecular Genetics
- DDeletion/duplication analysis
- Multiplex Ligation-dependent Probe Amplification (MLPA)
- Applied Biosystems 3730 capillary sequencing instrument
- Illumina MiSeq/NextSeq
- CSequence analysis of the entire coding region
- Next-Generation (NGS)/Massively parallel sequencing (MPS)
- Applied Biosystems 3730 capillary sequencing instrument
- Illumina MiSeq/NextSeq
Establish or confirm diagnosis
Clinical validity
HelpHow consistently and accurately the test detects or predicts the intermediate or final outcomes of interest. Lab-provided.It is estimated that ~80% of individuals with a clinical diagnosis of HNPP will carry the deletion encompasing PMP22. The remaining 20% are predicted to carry a deleterious point mutation in the PMP22 gene
- Hereditary Neuropathy with Liability to Pressure Palsies. - PubMed ID: 20301566
- https://www.ncbi.nlm.nih.gov/books/NBK1392
Testing strategy
HelpThe lab's suggested sequence of ordering tests based on clinical scenarios. It may include information on: reflex testing including each test component, and scenarios which prompt additional components of testing; whether lab communicates interim results or automatically proceeds to further analyses; and if any components are performed in another laboratory.Patient screened for Deletion of PMP22 gene and full coding sequence. 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 requisition provided on the website and ensure that it is signed by the referring physician
Test services
HelpLaboratory's order or catalog code for the test (used in the order requisition form).- Clinical Testing/Confirmation of Mutations Identified Previously
- Confirmation of research findings
- Custom Deletion/Duplication Testing
- Custom Sequence Analysis
- Custom mutation-specific/Carrier testing
- EuroGenetest, 2010Clinical utility gene card for: HMSN/HNPP HMSN types 1, 2, 3, 6 (CMT1,2,4, DSN, CHN, GAN, CCFDN, HNA); HNPP
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