Definition:

Oculopharyngeal muscular dystrophy (OPMD) is an autosomal dominant, late-onset muscle disease associated with progressive ptosis of the eyelids, dysphagia, and unique tubulofilamentous intranuclear inclusions (INIs) in skeletal muscle. OPMD is caused by expansions of the short (GCG) trinucleotide repeat in the coding sequence of the poly(A) binding protein nuclear 1 (PABPN1) gene. To date OPMD is considered as a primary myopathic disorder and there is little morphologic evidence for neurogenic etiology, though the peripheral nervous system (PNS) seems to be affected in some rare cases.