While muscular dystrophy (MD) used to define a single type of muscle disorder, it now encompasses more than 150 genetic subtypes of muscular diseases. At least that many genes are associated with progressive muscle disorders, and in the past 20 years, physicians have experienced an explosion in their knowledge of the genetic underpinnings of MD and disorder subtypes. For example, in the case of limb-girdle muscular dystrophy (LGMD), the fourth most common type of genetic muscle disease, scientists used to recognize only a single overarching category; now, there are at least 50 genes identified in causing disorders in a limb-girdle distribution, leading to a more refined classification and specific treatment options.
Penn State Hershey Medical Center conducts a large amount of clinical research in the genetic roots of muscle disease, and is internationally-renowned for its clinical expertise in LGMD, according to Matthew P. Wicklund, M.D., professor of neurology and pediatrics. In fact, after reviewing more than 3,000 articles over four years, Wicklund, along with nine other experts, published a definitive guideline on diagnosis and management of LGMD in October 2014.1 Many acquired and genetic muscle diseases present as weakness in the hip girdle, thighs, shoulder girdle and proximal arms, the classic “limb-girdle” pattern.2 Part of Wicklund’s responsibility is to further subtype those patients. Continue reading