Amyloidosis and exercise intolerance in ANO5 muscular dystrophy

Patient’s biopsy of the vastus lateralis muscle. Congo red stained sections visualized under rhodamine optics (A and B) and light microscopy (C) reveal amyloid deposits within the blood vessel walls (A, B, C; arrows) and around muscle fibers (B; asterisk). Immunoreactivity for dysferlin was observed in blood vessel walls independently from the presence of amyloid deposits (D).

Schematic representation of human ANO5 and location of the disease-causing mutations. ANO5 has eight transmembrane domains and intracellular N- and C-terminals. The resulting phenotypes are indicated in parentheses next to each mutation (dMD=distal muscular dystrophy; GDD=gnathodiaphyseal dysplasia; LGMD2L=limb girdle muscular dystrophy 2L). The arrows indicate the mutations detected in our patient.