The muscular dystrophies are genetic conditions that cause life-long disability from progressive muscle weakness. It is important to identify the specific genetic cause in each family as this allows doctors to plan health care and give accurate genetic counseling. Finding the specific gene mutation that is causing muscular dystrophy in a family is often difficult. One of the reasons is that there are over 40 different known genetic causes and the testing process can take years. Another reason is that it is likely that many disease genes that cause muscular dystrophy remain undiscovered. The Institute for Neuroscience and Muscle Research, based at the Children’s Hospital at Westmead, has been a leading research laboratory for muscular dystrophy for over 10 years. Through previous and ongoing projects, the INMR has provided over 100 muscular dystrophy families with genetic diagnoses and has contributed to finding many disease genes.
Through a technique called whole exome sequencing we have found two new likely causes of muscular dystrophy in different families. To confirm that these two new genes truly cause muscle disease, we will test 100 muscular dystrophy patients who remain without a diagnosis, aiming to find other families with mutations in these genes. We will also test whether some patients who have been diagnosed with limb-girdle muscular dystrophy (an umbrella term for over 20 different muscular dystrophies) in fact have myotonic dystrophy type 2 (DM2). DM2 affects people in similar ways to LGMD and is relatively common in many parts of Europe but is rarely diagnosed in Australia. We think DM2 may be under-recognized in Australia and some patients are mis-diagnosed with LGMD. To investigate this, we will test 60 LGMD patients who remain without a specific genetic diagnosis for DM2. The aim of these projects is to improve the ability of doctors to diagnose the genetic causes of muscular dystrophy to help with the care of affected people and their families.