Muscular dystrophies are a diverse group of inherited disorders characterized by progressive muscle weakness and wasting. The disorders are caused by mutations, or changes, in genes. Genes are tiny pieces of inherited material (DNA) that direct the body to make certain kinds of proteins.

In this study, researchers will examine the clinical presentation of muscular dystrophy caused by changes in the fukutin-related protein (FKRP) gene. FKRP mutations are responsible for limb-girdle muscular dystrophy type 2I (LGMD 2I) and congenital muscular dystrophy type 1C (MDC1C). Study researchers will also determine the reasons for differences in disease severity.

This study has two phases. Participants may take part in both phases, or in one of the two. Participants in the first phase will complete a brief, written survey on symptoms, test results, and medical history. Duration of this phase is 30-45 minutes. The second phase of the study involves a clinical evaluation at the University of Iowa, and brief surveys and diaries to be filled out at the participants' homes. The clinic evaluation includes muscle strength and motor ability testing, heart and lung function testing, and a review of past medical history. Portions of this evaluation — which lasts approximately 3-4 hours — will be repeated on a yearly basis. Surveys and diaries will be collected every 3-6 months and will take about 2 hours to complete.

Knowledge gained from this study will improve healthcare recommendations for people with FKRP mutations, and provide a baseline for further study, including potential treatment options.