Myotonic dystrophy type 2 (MD2), also known as proximal myotonic myopathy, is a very rare genetic multi-system disorder of late childhood or adult-onset characterized by mild myotonia, muscle weakness, and rarely cardiac conduction disorders. The disease is myotonic dystrophy type 2 (Monarch Disease Ontology entry MONDO_0011266). Also known as: CNBP myotonic dystrophy, myotonic dystrophy caused by mutation in CNBP, proximal myotonic dystrophy, proximal myotonic myopathy, ricker disease, ricker syndrome.