Application of molecular techniques for diagnosis of neuromuscular disorders

Abstract

CAMDND is a molecular diagnostic laboratory located in Sion, Mumbai. The main objective of the lab is to perform molecular tests for diagnosis of rare neuromuscular disorders. Neuromuscular disorders (NMDs) are inherited or acquired conditions that affect the skeletal muscles, motor neurons, or neuromuscular junctions. Most of them are characterized by a progressive damage of muscle fibers with reduced muscle strength, disability, and poor health-related quality of life of affected patients. The diagnosis is done with the help of various molecular techniques such as Multiplex Polymerase Chain Reaction for Duchene Muscular Dystrophy and Becker’s Muscular Dystrophy and technique such as Restriction Fragment Length Polymorphism for Spinal Muscular Atrophy. A literature survey on the neuromuscular disorders was conducted. As a result, the clinical symptoms of the various dystrophies and the genes and their variants that are responsible for the disorders could be identified. Hands on training on all the steps beginning from DNA Extraction, Polymerase Chain Reaction and Restriction Digestion to Gel Electrophoresis were conducted. Gels of different concentration and porosity are made for different samples (Muscular Dystrophies and Spinal Muscular Atrophy). During the sample collection, there was an interaction with the patients where the clinical history of the patient was collected. For getting precise results, certain samples are also outsourced for Next Generation Sequencing (NGS) as there are more than 6000 genes that are responsible for causing a neuromuscular disorder. The NGS reports includes all the gene variants (pathogenic or non pathogenic) that are responsible for the symptoms visible in the patient.