G.P.247

Mutations in dysferlin cause a variety of phenotypes collectively known as dysferlinopathies, including Limb Girdle Muscular Dystrophy type 2B and Myoshi Myopathy. Although there is currently no treatment for dysferlinopathies there is a need to develop clinically validated outcome measures in dysferlinopathy in preparation for future clinical trials. The International Clinical Outcomes Study for Dysferlinopathy (COS) is a multicentre international study, funded by The Jain Foundation and sponsored by Newcastle upon Tyne NHS Foundation Trust, which aims to develop and validate clinical outcome measures in addition to collecting natural history data. The recruitment target of 150 patients has now been successfully achieved, with a total of 193 patients recruited in 14 centres worldwide, including 38 UK patients. Data will be collected over 3years, including physiotherapy and medical assessments, MRI and questionnaires. In this poster we present data from screening questionnaires, including mutations identified and patient-reported details of disease presentation in all 38 UK patients. In total 49 different mutations were identified. Mean age at symptom onset was 22.3years and mean time to subsequent diagnosis was 6.1years. Polymyositis was initially incorrectly diagnosed in 6/38 patients. Lower limbs were the most common first affected area (23/38), and muscle weakness the most frequent first symptom (20/38). This data confirms that dysferlinopathies primarily present in young adulthood, often initially with lower limb symptoms, and are associated with significant allelic heterogeneity. Completion of this study and subsequent analyses will enhance our understanding of the natural history this variable condition.