Autophagic vacuolar myopathy caused by a CLN3 mutation. A case report.

We present a 29-year-old man with visual failure since childhood, muscle weakness, subtle heart muscle hypertrophy, and seizures who was initially considered to be affected by a mitochondrial encephalomyopathy because of the multiple unspecific involvement of brain, muscle and retinal tissues. Only the muscle biopsy findings correctly guided the genetic investigations and the identification of an autophagic vacuolar myopathy due to a homozygous mutation in CLN3. We believe that information in autophagic muscle disorders should further alert clinicians to consider CLN3 in individuals with vacuolar myopathy, especially if they have visual and cardiac involvement.