Muscle Disorders Panel

As part of Sanofi Canada’s sponsored Roadmap2Rare Diagnostic Program, an expanded 122‑gene muscle disorders (MD) panel is available at no charge to facilitate differential diagnosis of various muscular and neuromuscular diseases, including Pompe disease. This testing is made available in collaboration with Revvity Omics (formerly PerkinElmer Genomics).

This next-generation sequencing (NGS) testing is offered at no-charge and with complimentary genetic consultation/results interpretation for clinicians; genetic counselling for patients is also available. Clinicians can collect specimens with complimentary saliva swab kits or have Revvity mail kits directly to patients for self-collection.

Genetic testing criteria

To be eligible for testing on the panel, patients need to show laboratory evidence suggestive of a muscle pathology (i.e. EMG, CK, muscle biopsy, MRI), in addition to at least one of the following:

  • Muscle weakness, or
  • Unexplained respiratory insufficiency, or
  • Other symptom(s) suggesting muscle involvement (i.e. exercise intolerance, rhabdomyolysis, myalgia)

The Muscle Disorders Panel includes the following groups of disorders:

  • Muscular dystrophies with predominant limb-girdle weakness patterns,
  • Congenital muscular dystrophies,
  • Rigid spine syndrome,
  • Congenital myopathies,
  • Inclusion myopathies,
  • Congenital myasthenic syndromes,
  • Scapuloperoneal syndromes,
  • Metabolic myopathies

Limb-girdle muscular dystrophy (LGMD) is a heterogeneous group of genetic disorders characterized by progressive muscle weakness involving the shoulder and pelvic girdles.1 Pompe disease is a life-threatening, neuromuscular disorder that causes progressive and irreversible muscle damage.2

From a similar Canadian panel, of all diagnosed patients more than 36% of patients were diagnosed with an LGMD.3

Proximal muscle weakness

Progressive proximal muscle weakness affects the majority of late-onset Pompe patients.5

  1. Progressive proximal muscle weakness – especially in lower limbs.4,5
  2. Respiratory insufficiency because of diaphragm weakness.6
  3. Mild-to-moderate hyperckemia levels.6

>80% of patients   50-80% of patients   <50% of patients

Distribution of skeletal muscle weakness in 94 adults with Pompe disease. Adapted from van der Beek.5

Though symptoms vary, progressive proximal muscle weakness, with or without respiratory insufficiency or hyperckemia, should raise suspicion of Pompe disease.6

Genes included in the Muscle Disorders Panel

For more information about the Roadmap2Rare Diagnostic Program services, and to access the MD panel, please visit the Revvity Omics Roadmap2Rare landing page. Patient and physician identifying information provided to Revvity remains confidential and is not shared with Sanofi.

References:

  1. Limb-Girdle Muscular Dystrophy. Muscular Dystrophy Canada website. https://muscle.ca/discovermd/types-of-neuromusculardisorders. Accessed Jan 20, 2020.
  2. Hagemans MLC et al. Neurology. 2005;64(12):2139-2141.
  3. Thuriot et al. Neurol Genet. 2020;6(2):e408.
  4. Hirschhorn R et al. Glycogen storage disease type II: acid alpha-glucosidase (acid maltase) deficiency. In: Scriver CR et al, eds. The Metabolic & Molecular Bases of Inherited Disease. 8th ed. New York, NY: McGraw-Hill; 2001:3389- 3420.
  5. Van der Beek N et al. Orphanet J Rare Dis. 2012;7:88.
  6. American Association of Neuromuscular & Electrodiagnostic Medicine. Muscle Nerve. 2009;40(1):149-160.

The Roadmap2Rare Diagnostic Program is not intended to and should not interfere in any way with a clinician’s or patient’s independent judgment and freedom of choice in the testing and treatment options for these diseases. Clinicians and patients should always consider the full range of testing and treatment options and select those most appropriate for the individual patient. The identifying information of patients and clinicians is not shared with Sanofi Canada.