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HelpTest ID: LGCMP Inherited Limb-Girdle Muscular Dystrophy and Congenital Myasthenic Syndrome Gene Panel, Varies
Ordering Guidance
Targeted testing for familial variants (also called site-specific or known mutations testing) is available for the genes on this panel. See FMTT / Familial Variant, Targeted Testing, Varies. To obtain more information about this testing option, call 800-533-1710.
Customization of this panel and single gene analysis for any gene present on this panel are available. For more information see CGPH / Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies.
Shipping Instructions
Specimen Required
Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. For instructions for testing patients who have received a bone marrow transplant, call 800-533-1710.
Submit only 1 of the following specimens:
Specimen Type: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA) or yellow top (ACD)
Acceptable: None
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
Specimen Stability Information: Ambient (preferred) 4 days/Refrigerated 4 days/Frozen 4 days
Additional Information:
1. Specimens are preferred to be received within 4 days of collection. Extraction will be attempted for specimens received after 4 days, and DNA yield will be evaluated to determine if testing may proceed.
2. To ensure minimum volume and concentration of DNA is met, the requested volume must be submitted. Testing may be canceled if DNA requirements are inadequate.
Patient Preparation: Patient should not eat, drink, smoke, or chew gum 30 minutes prior to collection.
Supplies: Saliva Swab Collection Kit (T786)
Specimen Volume: 1 Swab
Collection Instructions: Collect and send specimen per kit instructions.
Specimen Stability Information: Ambient (preferred) 30 days/Refrigerated 30 days
Additional Information: Saliva specimens are acceptable but not recommended. Due to lower quantity/quality of DNA yielded from saliva, some aspects of the test may not perform as well as DNA extracted from a whole blood sample. When applicable, specific gene regions that were unable to be interrogated will be noted in the report. Alternatively, additional specimen may be required to complete testing.
Specimen Type: Extracted DNA
Container/Tube:
Preferred: Screw Cap Micro Tube, 2 mL with skirted conical base
Acceptable: Matrix tube, 1 mL
Collection Instructions:
1. The preferred volume is at least 100 mcL at a concentration of 75 ng/mcL.
2. Include concentration and volume on tube.
Specimen Stability Information: Frozen (preferred) 1 year/Ambient/Refrigerated
Additional Information: DNA must be extracted in a CLIA-certified laboratory or equivalent and must be extracted from a specimen type listed as acceptable for this test (including applicable anticoagulants). Our laboratory has experience with Chemagic, Puregene, Autopure, MagnaPure, and EZ1 extraction platforms and cannot guarantee that all extraction methods are compatible with this test. If testing fails, one repeat will be attempted, and if unsuccessful, the test will be reported as failed and a charge will be applied. If applicable, specific gene regions that were unable to be interrogated due to DNA quality will be noted in the report.
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing (Spanish) (T826)
2. Molecular Genetics: Neurology Patient Information
3. If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.
Useful For
Establishing a molecular diagnosis for patients with limb-girdle muscular dystrophy or congenital myasthenic syndrome
Identifying variants within genes known to be associated with limb-girdle muscular dystrophy or congenital myasthenic syndrome, allowing for predictive testing of at-risk family members
Genetics Test Information
This test utilizes next-generation sequencing to detect single nucleotide and copy number variants in 65 genes associated with limb-girdle muscular dystrophy and congenital myasthenic syndrome: AGRN, ALG14, ALG2, ANO5, BIN1, BVES, CAPN3, CAV3, CHAT, CHRNA1, CHRNB1, CHRND, CHRNE, COL13A1, COL6A1, COL6A2, COL6A3, COLQ, CRPPA, DAG1, DES, DNAJB6, DNM2, DOK7, DPAGT1, DPM3, DYSF, FKRP, FKTN, GAA, GFPT1, GMPPB, HNRNPDL, LAMA2, LAMB2, LMNA, LRP4, MUSK, MYOT, PLEC, POGLUT1, POMGNT1, POMGNT2, POMK, POMT1, POMT2, PREPL, RAPSN, SCN4A, SGCA, SGCB, SGCD, SGCG, SLC18A3, SLC25A1, SLC5A7, SYT2, TCAP, TNPO3, TOR1AIP1, TRAPPC11, TRIM32, TTN, VAMP1, VCP. For more information see Method Description and Targeted Genes and Methodology Details for Inherited Limb-Girdle Muscular Dystrophy and Congenital Myasthenic Syndrome Gene Panel.
Identification of a disease-causing variant may assist with diagnosis, prognosis, clinical management, recurrence risk assessment, familial screening, and genetic counseling for limb-girdle muscular dystrophy and congenital myasthenic syndrome.
Method Name
Sequence Capture and Targeted Next-Generation (NGS) Sequencing followed by Polymerase Chain Reaction (PCR) and Sanger Sequencing
Reporting Name
LGMD and CMS Gene PanelSpecimen Type
VariesSpecimen Minimum Volume
See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Varies | |
Clinical Information
The limb-girdle muscular dystrophies (LGMD) are a heterogeneous group of muscular dystrophies that show progressive weakness and muscle atrophy, predominantly affecting the hips, shoulders, and proximal extremity muscles. There is wide variability in age of onset, severity, and clinical presentation within the LGMD spectrum.
Congenital myasthenic syndromes occur as a result of compromised neuromuscular transmission. Clinical manifestations include fatigable weakness involving ocular, bulbar, and limb muscles. The severity and disease course are highly variable, but individuals usually present in infancy or early childhood. The clinical phenotype associated with a neonatal onset can include feeding difficulties, poor suck and cry, choking spells, eyelid ptosis, and muscle weakness. The clinical phenotype associated with a later childhood onset can include abnormal muscle fatigue, delayed motor milestones, ptosis, and extraocular muscle weakness.
The clinical overlap of limb-girdle muscular dystrophy and limb-girdle congenital myasthenic syndromes can make these conditions difficult to distinguish clinically. Misdiagnoses can lead to diagnostic delays of several decades, impacting prognostic predictions and appropriate management. This multigene panel can be an efficient and cost-effective way to establish a molecular diagnosis.
Reference Values
An interpretive report will be provided.
Interpretation
All detected variants are evaluated according to American College of Medical Genetics and Genomics recommendations.(1) Variants are classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.
Clinical Reference
1. Richards S, Aziz N, Bale S, et al. Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med. 2015;17(5):405-424
2. Nicolau S, Milone M, Liewluck T. Guidelines for genetic testing of muscle and neuromuscular junction disorders. Muscle Nerve. 2021;64(3):255-269
3. Mitsuhashi S, Kang PB. Update on the genetics of limb girdle muscular dystrophy. Semin Pediatr Neurol. 2012;19(4):211-218.
4. Iyadurai SJP. Congenital myasthenic syndromes. Neurol Clin. 2020;38(3):541-552
Day(s) Performed
Varies
Report Available
21 to 28 daysTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81443
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| LGCMP | LGMD and CMS Gene Panel | In Process |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 617624 | Test Description | 62364-5 |
| 617625 | Specimen | 31208-2 |
| 617626 | Source | 31208-2 |
| 617627 | Result Summary | 50397-9 |
| 617628 | Result | 82939-0 |
| 617629 | Interpretation | 69047-9 |
| 618184 | Additional Results | 82939-0 |
| 617630 | Resources | 99622-3 |
| 617631 | Additional Information | 48767-8 |
| 617632 | Method | 85069-3 |
| 617633 | Genes Analyzed | 48018-6 |
| 617634 | Disclaimer | 62364-5 |
| 617635 | Released By | 18771-6 |
Testing Algorithm
For information see Neuromuscular Myopathy Testing Algorithm.
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