Facioscapulohumeral muscular dystrophy: do neurotrophins play a role?

Although the molecular defect of facioscapulohumeral muscular dystrophy (FSHD) is well established and involves the contraction of the polymorphic 3.3 kb D4Z4 repeat on the subtelomeric region of chromosome 4q35, the pathologic effects of this deletion remain largely unknown. As a consequence, no specific treatment for FSHD is at present available. Thus, there is the need to explore new areas in an attempt to better characterize pathophysiological alterations in FSHD that might be useful for managing the disease. Neurotrophins (nerve growth factor, brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5) are a class of proteins involved in the development, maintenance, and function of neurons of the peripheral and central nervous systems. In addition, neurotrophins and their RNAs are expressed in muscle, where they have a role in development and regeneration. In this article we put together the experimental evidence that indicates neurotrophins might be involved in the pathophysiology of FSHD and discuss the possible implications of this assumption.