KMT2B and Dystonia: KMT2B and VPS16 are also well validated, bringing the total number of monogenic dystonias to at least six, plus a longer list of combined dystonias such as PANK2, ATP1A3, SCGE, etc. Monogenic sporadic and inherited types of isolated dystonia are caused by rare variations in these genes; frequent variations may impart risk and suggest that dystonia is a polygenic feature in a subset of instances [39].