Proteins involved in muscular dystrophies Proteins involved in muscular dystrophies. This schematic shows the location of various sarcolemmal, sarcomeric, nuclear, and enzymatic proteins associated with muscular dystrophies. The diseases associated with mutations in the genes responsible for encoding these proteins are shown in boxes. Dystrophin, via its interaction with the dystroglycan complex, connects the actin cytoskeleton to the extracellular matrix. Extracellularly, the sarcoglycan complex interacts with biglycan, which connects this complex to the dystroglycan complex and the extracellular matrix collagen. Various enzymes are important in the glycosylation of the α-dystroglycan and mediate its binding to the extracellular matrix and usually cause a congenital muscular dystrophy with severe brain and eye abnormalities, but may cause milder LGMD phenotype. Mutations in genes that encode for sarcomeric and Z-disc proteins cause forms of LGMD and distal myopathies (including myofibrillar myopathy, forms of hereditary inclusion body myopathy) as well as nemaline rod myopathy and other "congenital" myopathies. Mutations affecting nuclear membrane proteins are responsible for most forms of EDMD. Mutations in other nuclear genes cause other forms of dystrophy. Source: Muscular Dystrophies, Neuromuscular Disorders, 2e Citation: Amato AA, Russell JA. Neuromuscular Disorders, 2e; 2015 Available at: https://neurology.mhmedical.com/DownloadImage.aspx?image=/data/books/1561/ama_ch27_f001.png&sec=96695975&BookID=1561&ChapterSecID=96695969&imagename= Accessed: October 30, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved