Myotonic dystrophy type 1 (DM1) is an autosomal dominant, multisystemic disease caused by an expansion of a CTG trinucleotide repeat in the 3′ untranslated region of the dystrophia myotonica protein kinase gene (DMPK; OMIM 160900). This evidence concerns the gene WEE1 and myotonic dystrophy type 1.