Monarch Disease Ontology term MONDO_0008045 (spinal muscular atrophy-progressive myoclonic epilepsy syndrome) is characterized by hereditary myoclonus and progressive distal muscular atrophy. Less than 10 cases have been reported. Treatment with clonazepam results in complete and lasting improvement of the myoclonus. Also known as: Jankovic-Rivera syndrome, hereditary myoclonus-progressive distal muscular atrophy syndrome.