Total 77 clinical symptoms reported for Juvenile myopathy, encephalopathy, lactic acidosis AND stroke  Very Frequent (9)Uncommon (3)Occasional (40)Frequent (25)

Aphasia	An acquired language impairment of some or all of the abilities to produce or comprehend speech and to read or write.   Synonyms:Difficulty finding words; Losing words; Loss of words	Very frequent
Aplasia/Hypoplasia of the cerebral white matter	Absence or underdevelopment of the cerebral white matter.   Synonyms:Absent/small cerebral white matter; Absent/underdeveloped cerebral white matter	Very frequent
Dementia	A loss of global cognitive ability of sufficient amount to interfere with normal social or occupational function. Dementia represents a loss of previously present cognitive abilities, generally in adults, and can affect memory, thinking, language, judgment, and behavior.   Synonyms:Dementia; Dementia, progressive; Progressive dementia	Very frequent
Migraine	Migraine is a chronic neurological disorder characterized by episodic attacks of headache and associated symptoms.   Synonyms:Intermittent migraine headaches; Migraine; Migraine headache; Migraine headaches	Very frequent
Muscle weakness	Reduced strength of muscles.   Synonyms:Muscle weakness; Muscular weakness	Very frequent
Ragged-red muscle fibers	An abnormal appearance of muscle fibers observed on muscle biopsy. Ragged red fibers can be visualized with Gomori trichrome staining as irregular and intensely red subsarcolemmal zones, whereas the normal myofibrils are green. The margins of affect fibers appear red and ragged. The ragged-red is due to the accumulation of abnormal mitochondria below the plasma membrane of the muscle fiber, leading to the appearance of a red rim and speckled sarcoplasm.   Synonyms:Mitochondrial proliferation in muscle tissue; Ragged red muscle fibers; Ragged-red fibers	Very frequent
Seizure	A seizure is an intermittent abnormality of nervous system physiology characterised by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.   Synonyms:Epileptic seizure; Seizures	Very frequent
Stroke-like episode	No consensus exists on what a stroke-like episode is, but these episodes can be functionally defined as a new neurological deficit, occurring with or without the context of seizures, which last longer than 24 hours.   Synonyms:Stroke-like episodes; Strokelike episodes	Very frequent
Widened cerebral subarachnoid space	An increase in size of the anatomic space between the arachnoid membrane and pia mater in the region surrounding the cerebrum.	Very frequent