A focused phenotypic and algorithmic approach to diagnosis    

Enabling confidence through expert-backed analysis

Genetic testing to identify hereditary neuromuscular disorders, which are varied in presentation and even more diverse in their specific genetic causes, can be complex. Mayo Clinic Laboratories’ distinctive approach to next-generation sequencing (NGS) enables optimal mutation detection and interpretation through targeted capture techniques, confirmation using laboratory-developed criteria, and unique reporting methods.

This process eliminates the risk of false negative results compared to whole-exome sequencing and other capture techniques, providing physicians with confidence that disease-specific mutations have not been missed.

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 and mutation detection can identify variations 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,1 reducing costs and enhancing patient care. Test results are reported with interpretive comments detailing the potential or known significance of detected variations.

Which test should I order?

NMPAN    | Neuromuscular Genetic Panels by Next-Generation Sequencing (NGS), Varies

Useful for:

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

Includes:

Distal myopathy + Peripheral neuropathy

Distal Weakness Expanded Panel (217 genes)

Motor neuron disease

Motor Neuron Disease Panel (17 genes)

Myopathy

Myopathy Expanded Panel (141 genes)

Muscular Dystrophy Panel (77 genes)

Congenital Myopathy Panel (36 genes)

Metabolic Myopathy Panel (41 genes)

Myofibrillar Myopathy Panel (12 genes)

Distal Myopathy Panel (27 genes)

Emery-Dreifuss Panel (5 genes)

Rhabdomyolysis and Myopathy Panel (31 genes)

Neuromuscular junction

Myasthenic Syndromes Panel (25 genes)

Hyperexcitable muscle disease

Skeletal Muscle Channelopathy Panel (6 genes)

DBMD    | Duchenne/Becker Muscular Dystrophy, DMD Gene, Large Deletion/Duplication Analysis, Varies

C9ORF    | C9orf72 Hexanucleotide Repeat, Molecular Analysis, Varies

Useful for:

  • Molecular confirmation of clinically suspected cases of c9FTD/ALS, frontotemporal dementia (FTD), or amyotrophic lateral sclerosis (ALS)
  • Presymptomatic testing for individuals with a family history of c9FTD/ALS and a documented expansion in the C9orf72 gene

MXB    | Muscle Pathology Consultation

PNBX    | Peripheral Nerve Pathology Consultation

SPBX    | Epidermal Nerve Fiber Density Consultation, Varies

Test in Focus

Christopher Klein, M.D., a neurologist at Mayo Clinic, provides an overview of neuromuscular testing. He discusses which types of patients should be tested, the benefits of our approach, how this approach improves upon previous methods, and the role that functional assays play in diagnosis.

Learn more

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

References

  1. Kotzer KE, Riley JD, Conta JH, et al. Genetic testing utilization and the role of the laboratory genetic counselor. Clin Chim Acta. 2014;427:193-195. doi: 10.1016/j.cca.2013.09.033