Table 1.

Summary of main clinical features that differ between both DM forms.

Features	DM1	DM2
Age of onset	At any age	Adulthood
Congenital forms	Yes	No
Gene expansion	DMPK, (CTG)n	CNBP, (CCTG)n
Predominantly affected muscles	Distal	Proximal
Predominantly affected fibers	Type 1	Type 2