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8 | InTouch JUNE 2022 Limb-girdle muscular dystrophy are progressive muscle disorders that result from alterations in one or more of the genes needed for normal muscle structure and function. The changes in the muscle, such as muscle fibre death, can be seen on biopsied samples of muscle tissue. Time of onset varies, but often begins in childhood. Symptoms are slowly progressive, impacting the proximal muscles. Diagnosis is by DNA analysis, and if required muscle biopsy. Changes in technology have meant that multiple genes can now be screened for at one time, whereas years ago only one gene at a time could be looked at – for about the same cost as today’s multiple gene panels. This means that many older adults with LGMD are yet to be genetically diagnosed as they received a clinical diagnosis at a time when the technology wasn’t available for them to be more accurately diagnosed. Currently treatment is focused on maintenance of function and prevention of contractures, as well as cardiac care for those with a sub-type where the heart is also affected. However, the landscape of treatment in LGMD is rapidly changing. There are an increasing number of clinical trials being planned for specific types of LGMD – accurate diagnosis is essential to being able to participate. LGMD, at last count, has 31 known subtypes, 23 autosomal recessive and eight autosomal dominant. As a group, LGMD’s are the fourth most common inherited muscle disease (after myotonic dystrophy, dystrophinopathies, and FSHD). In NZ the overall prevalence was reported to be 2.19 per 100 000*, which appears similar to elsewhere around the world. Males and females are affected equally. The Neurogenetic Research team at Auckland Hospital has Limb-girdle muscular dystrophy is an umbrella term for numerous subtypes of muscular dystrophy; all of which are inherited, some in an autosomal recessive way and some in an autosomal dominant way. Genetic diagnosis for limb- girdle muscular dystrophy GETTING TRIAL-READY FEATURE recently completed an audit of patients with LGMD enrolled in Pūnaha Io the NZ Neuro-Genetic Registry & Biobank. The audit, carried out by Dr Avroneel Ghosh, identified 21 adult patients with LGMD in NZ who have no molecular diagnosis. Of these, 13 have not had any clinical genetic testing. Six of the remaining eight, who are undiagnosed after neuromuscular gene panels have proven negative, have consented to participate in the Finding the Gene study, also run by the Neurogenetic Research team at ADHB. It’s anticipated that approximately half of those patients who have not received any clinical genetic testing would return a result from an appropriate neuromuscular panel. The remaining six – seven patients will be offered a place in the Finding the Gene study. The Neurogenetic Research Team is grateful to the Richdale Trust, Neuromuscular Research NZ, and MDANZ for providing the necessary funding to facilitate the recruitment of undiagnosed patients into the Finding the Gene study, and covering the costs of shipping DNA to our collaborators at The Broad Institute, Boston, USA. The Neurogenetic Research, team under the leadership of Associate Professor Richard Roxburgh, is housed within ADHB; their research focus is nation-wide, providing nationwide equity. The team is the only one undertaking this type of research in adults with neurogenetic conditions in NZ and are looking forward to being able to provide an update on the numbers of diagnosed people with LGMD within NZ. *Theadom A, Rodrigues M, Poke G, O’Grady G, Love D, Hammond-Tooke G, Parmar P, Baker R, Feigin V, Jones K, Te Ao B, Ranta A, Roxburgh R; on Behalf of the MDPrev Research Group. A Nationwide, Population-Based Prevalence Study of Genetic Muscle Disorders. Neuroepidemiology.