Expert Consensus on Genetic Diagnostic Approaches for Patients With Limb-Girdle Muscular Dystrophy

Limb-girdle muscular dystrophy (LGMD) is the phenotypic description of a clinically and genetically diverse group of inherited neuromuscular disorders involving proximal muscles of the pelvic and shoulder girdles. There are currently over 30 different genetic forms of LGMD, and despite diagnostic advances, accurate diagnoses may be difficult to achieve. Although clinical diagnosis of a patient with a specific form of LGMD is possible in some cases, a precise and timely genetic diagnosis can be crucial to anticipate and prevent complications associated with particular genetic forms of LGMD (e.g., extramuscular manifestations such as cardiac, respiratory, or cognitive impairments). With the rapid pace of genetic testing advances, updates on training and education are imperative to support the correct use of these tests. We formed an expert consensus to provide an efficient diagnostic approach meant to empower clinicians in the use of genetic and other supportive tests. Informed selection and interpretation of a gene panel; use of genome or exome sequencing; and use of biochemical, imaging, pathology, and electromyography tests are discussed here. Ultimately, genetic testing should help to confirm a diagnosis and guide treatment decisions or counseling services.