| Type of DM | Cataracts | Cardiac abnormalities | Cognitive impairment; personality disturbance | Endocrine disturbance | Gastrointestinal disorder |
| DM I (Steinert disease) | Very common; almost universal late in course[1] | Conduction disturbances well recognized and common late in course[1] Progressive cardiomyopathy also described | Intellectual disability is common with congenital DM I; mild to moderate cognitive and personality defects in adult form | Glucose intolerance: well recognized and common late in course[1] Hypogonadism: common and almost universal late in course[1] | Irritable bowel symptoms; dysphagia; gall stones |
| DM II (Proximal myotonic myopathy) | Common (78% in subjects >50 years)[2] | Conduction disturbances less problematic than DM I (19% when considered across age spectrum [21 to >50 years][2]) Progressive cardiomyopathy also described | Mild cognitive impairment may be seen | Glucose intolerance: common, seen in 75%[2] Hypogonadism: seen in 29%[2] | Yes, but not as pronounced as in DM I; dysphagia common but relatively mild |
