A phenotypic-directed testing approach    

Identify genetic causes through next-generation sequencing or enhanced diagnosis through next-generation sequencing

The emergence of advanced, molecular testing technologies has enhanced the detection of inherited, neuromuscular disorders. However, diverse presentation and varying genetic causes of these conditions often lead to lengthy diagnostic journeys when traditional testing strategies are used. Genetic testing to achieve molecular diagnosis of neuromuscular disease is integral to optimizing patient care.1

Mayo Clinic Laboratories’ distinctive approach to testing for genetic neuromuscular disorders uses phenotypic information to streamline diagnosis. Phenotype-specific panels enable targeted testing, improving diagnosis and minimizing uncertain results.

By the numbers

215

genes in our comprehensive panel

16

focused neurogenetic panels

4

single gene evaluations

Full-spectrum testing

Our robust suite of genetic testing for inherited neuromuscular disorders includes both comprehensive and targeted next-generation sequencing panels. Developed by an integrated team of clinicians, geneticists, and laboratory testing experts, our panels were carefully vetted to only include clinically relevant genes identified in literature and recommended in numerous professional clinical treatment guidelines.

Use of next-generation sequencing enables full gene coverage on all included genes and provides high sensitivity for the detection of both small and copy number variants. Our comprehensive genetic panel analyzes 215 genes associated with inherited neuromuscular diseases, including muscular dystrophy, myopathy, rhabdomyolysis, congenital myasthenic syndrome, skeletal muscular channelopathy, and mitochondrial syndromes, among others. Our focused panels span the array of neuromuscular illnesses including ataxia with neuropathy, myasthenia, and muscular dystrophy.

The Mayo Clinic difference

Mayo Clinic’s board-certified laboratory directors, in collaboration with clinical neurologists, pathologists, and genetic counselors, provide the highest standard of testing for hereditary neuromuscular disorders. In instances of inconclusive skin, nerve, or muscle pathological evaluations, molecular genetic testing can identify variants for hereditary neuromuscular disorders. All detected variants are evaluated based on American College of Medical Genetics and Genomics recommendations.

Genetic counselors add value to proper test utilization by assisting with case review and coordination to ensure the most appropriate test is ordered. On average, genetic counselors modify 8% of all reviewed genetic test orders,2 reducing costs and enhancing patient care. Test results are reported with interpretive comments detailing the potential or known significance of detected variants.

Key testing

MUPAN    | Comprehensive Neuromuscular Gene Panel, Varies

  • Establishes diagnosis of a neuromuscular disorder associated with known causal genes.
  • Serves as second-tier testing for patients in whom previous targeted gene mutation analyses for specific inherited neuromuscular disorder-related genes were negative.
  • Identifies mutations within genes known to be associated with inherited neuromuscular disorders, allowing for predictive testing of at-risk family members.

Neuromuscular gene panel provides comprehensive analysis

Zhiyv (Neal) Niu, Ph.D., and Christopher Klein, M.D., explain how Mayo Clinic Laboratories' updated neuromuscular gene panel informs diagnosis and treatment. The phenotype-based panel covers the complete list of neuromuscular genes and their variants.

Hyperexcitable muscle disease

SMCP   | Inherited Skeletal Muscle Channelopathy Gene Panel, Varies

  • Evaluates five genes associated with hereditary skeletal muscle channelopathies.

Motor neuron disease

MNDP   | Inherited Motor Neuron Disease Gene Panel, Varies

  • Evaluates 33 genes associated with motor neuron disease and repeat expansion analysis for C9orf72.

SOD1Z  | SOD1 Gene, Full Gene Analysis, Varies

  • Detects single nucleotide and copy number variants in the SOD1 gene, which is associated with amyotrophic lateral sclerosis.

C9ORF    | C9orf72 Hexanucleotide Repeat, Molecular Analysis, Varies

  • Confirms clinically suspected cases of c9FTD/ALS, frontotemporal dementia (FTD), or amyotrophic lateral sclerosis (ALS).

SMNDX   | Spinal Muscular Atrophy Diagnostic Assay, Deletion/Duplication Analysis, Varies

  • Detects and quantifies survival motor neuron 1 (SMN1) exon 7, SMN2 exon 7, and SMN1 rs143838139 (g.27134T>G) associated with spinal muscular atrophy (SMA).

SBULB   | Spinobulbar Muscular Atrophy (Kennedy Disease), Molecular Analysis, Varies

  • Detects amplification-type mutations within the AR gene.

Myopathy

RABMP   | Inherited Rhabdomyolysis and Metabolic Myopathy Panel, Varies

  • Evaluates 83 genes associated with rhabdomyolysis and metabolic myopathy.

Neuromuscular junction

CMSP   | Inherited Congenital Myasthenic Syndrome Gene Panel, Varies

  • Evaluates 28 genes associated with congenital myasthenic syndromes.

LGCMP   | Inherited Limb-Girdle Muscular Dystrophy and Congenital Myasthenic Syndrome Gene Panel, Varies

  • Evaluates 65 genes associated with limb-girdle muscular dystrophy and congenital myasthenic syndrome.

CGPH    | Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies

  • Custom gene lists can be reused for multiple patients.

Neuropathy and Neuromuscular Gene Panel Update

In this "Hot Topic," Christopher Klein, M.D., and Zhiyv (Neal) Niu, Ph.D., discuss how Mayo Clinic’s neuropathy and neuromuscular gene panels have enhanced patient care.

Learn more about how to order these tests at your institution.


References

  1. KASSARDJIAN, C., AMATO, A., BOON, A., CHILDERS, M., KLEIN, C. AANEM PROFESSIONAL PRACTICE COMMITTEE. The Utility of Genetic Testing in Neuromuscular Disease: A Consensus Statement from the AANEM on the Clinical Utility of Genetic Testing in Diagnosis of Neuromuscular disease. Policy Department, American Association of Neuromuscular & Electrodiagnostic Medicine, Rochester, Minnesota, USA. Accepted 22 August 2016