Our Neuromuscular Test Menu Just Got Stronger
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At PreventionGenetics, we’re constantly striving to provide the best genetic tests possible.We have updated several of our panels for specific neuromuscular disorders (NMDs) including Congenital Myopathy, Limb-Girdle Muscular Dystrophy, and Myofibrillar Myopathy. A 124 gene Comprehensive Neuromuscular Panel as well as a 83 gene Metabolic Myopathies, Rhabdomyolysis and Exercise Intolerance Sequencing Panel are now available.
What Are Neuromuscular Disorders?
NMDs are a clinically, pathologically, and genetically heterogeneous group of diseases that result in muscle weakness. This may result from issues with the peripheral nerves, the neuromuscular junction, or the muscle itself (McDonald 2012). These disorders tend to cause muscle weakness, degeneration, pain, and joint contractures. This term also encompasses several syndromes that include additional complications such as respiratory issues, spinal deformities and cardiomyopathy. Although we focus on inherited NMDs at PreventionGenetics, they can also be acquired or induced by environmental factors. The inheritance pattern for NMDs also varies greatly including those inherited in an autosomal dominant, recessive, and X-linked pattern. Conditions like Limb-Girdle Muscular Dystrophy can be inherited in either an autosomal dominant or recessive manner (Zatz et al. 2016).
Diagnosis
Traditionally, NMDs were diagnosed using clinical features, electromyography (EMG), muscle biopsy, and biochemical testing (McDonald 2012). Recently, DNA sequencing has become a common diagnostic tool as the price of sequencing has gone down and the size of Next Generation Sequencing (NGS) panels has grown (Vasli et al. 2012). Genetic testing is particularly useful for NMDs such as Limb-Girdle Muscular Dystrophy because the severity and age of onset can vary within a single disorder based on any causative and modifying variants that may be present (Zatz et al. 2016). Proper diagnosis of NMDs is crucial for offering treatments and an accurate prognosis. Some NMDs are more progressive than others, or are associated with an elevated risk of developing complications such as scoliosis, contractures, or cardiac disorders (Skalsky & McDonald 2012). Even within a specific disorder, identifying the causative variant(s) can provide valuable information for gene-specific treatments and for reproductive planning.
Testing Available at PreventionGenetics
Our Comprehensive Neuromuscular Panel includes 142 genes associated with limb-girdle muscular dystrophies, congenital muscular dystrophies, congenital myopathies, distal myopathies, myotonias, congenital myasthenic syndrome and distal arthrogryposis. Although the clinical sensitivity varies depending on the specific NMD and individual indications for testing, recent studies using a similar 93 gene panel and a 180 gene primary myopathy panel obtained either a clear or likely molecular diagnosis in approximately 43% and 34% of participants, respectively (Savarese et al. 2016, Evilä et al. 2016).
Quality of Testing
At PreventionGenetics, quality is very important to us. For the great majority of our panels, we supplement our NGS data with Sanger sequence to ensure complete, reliable coverage throughout the panel. Additionally, all of our clinical test results are carefully reviewed by four experienced employees, including two PhD level Geneticists.
Don’t see what you need?
f you are interested in a panel that is not currently offered our menu, build a custom panel on our whole-exome sequencing platform using our Custom Panel Tool.
Citations
- Craig McDonald 2012. Physical Medicine & Rehabilitation Clinics of North America. 23(3): 495–563. PubMed ID: 22938875
- Evilä et al. 2016. Neuromuscular Disorders. 26(1):7-15. PubMed ID: 26627873
- Savarese et al. 2016. Neurology. 87(1): 71-6. PubMed ID: 27281536
- Andrew Skalsky & Craig McDonald 2012. Physical Medicine & Rehabilitation Clinics of North America. 23(3): 675-687. PubMed ID: 22938881
- Vasli et al. 2012. Acta Neuropathologica. 124 (2): 273-283. PubMed ID: 22526018
- Zatz et al. 2016. Genetics and Molecular Biology. 39(3): 339–348. PubMed ID: 27575431.