Oculopharyngeal muscular dystrophy (OPMD) is a late-onset, mostly autosomal dominant muscular disorder, caused by the expansion of the trinucleotide repeat GCG in the 5′ end of the poly-A binding protein nuclear 1 (PABPN1) gene. The gene discussed is PABPN1; the disease is oculopharyngeal muscular dystrophy.