Total 99 clinical symptoms reported for Steinert myotonic dystrophy syndrome  Very Frequent (5)Uncommon (17)Occasional (62)Frequent (15)

Cardiac conduction abnormality	Any anomaly of the progression of electrical impulses through the heart.   Synonyms:Abnormality of cardiac conduction; Abnormality of cardiac conduction system; Cardiac conduction abnormalities; Cardiac conduction defects; Heart conduction disorder	Very frequent
Distal muscle weakness	Reduced strength of the musculature of the distal extremities.   Synonyms:Distal limb muscle weakness; Distal limb weakness; Distal muscular weakness; Distal paresis; Muscle weakness, distal; Muscle weakness, distal limbs, due to neuronopathy; Weakness of distal muscles; Weakness of outermost muscles	Very frequent
Excessive daytime somnolence	A state of abnormally strong desire for sleep during the daytime.   Synonyms:Excessive daytime sleepiness; More than typical sleepiness during day	Very frequent
Myotonia with warm-up phenomenon	Myotonia that occurs after a period of rest and decreases with continuing exercise.	Very frequent
Posterior subcapsular cataract	A type of cataract affecting the posterior pole of lens immediately adjacent to ('beneath') the Lens capsule.   Synonyms:Posterior subcapsular opacities of the lens	Very frequent