DMPK and myotonic dystrophy type 1: Out of four types of myotonic dystrophy, myotonic dystrophy types 1 and 2 (DM1 and DM2) are most common and caused by mutation in two different genes DMPK (Dystrophia myotonica protein kinase) and cellular nucleic acid-binding protein, that is, CNBP (previously known as ZNF9, that is, Zinc finger protein [3, 4]).