The onset and progression of cardiac involvement in juvenile neuronal ceroid lipofuscinosis (Batten disease) are studied in 29 children and adolescents with genetically verified disease at Aarhus University Hospital, Skejby, Denmark. One third of initial EKGs had abnormal deeply inverted T waves. Repolarization disturbance of ventricular myocardium at initial recording correlated with risk of death during the 7-year observation period. Heart rate and variability were significantly reduced with increasing age, suggesting a decreased parasympathetic activity on the heart or negative influence on sinus node automaticity. Bradycardia, arrhythmia, sinus arrests and atrial flutter indicated an age-dependent decrease in sinus node activity. In their early 20s, ventricular hypertrophy was a frequent finding. 
COMMENT. Juvenile neuronal ceroid lipofuscinosis (JNCL, Batten disease), caused by mutations in the CLN3 gene and failure to respond to oxidative stress (Tuxworth RJ. Hum Mol Genet 201l;Mar 15[Epub ahead of print]), is the most common type of inherited lysosomal storage and neurodegenerative disease. The clinical course is characterized by progressive visual failure, dementia, and seizures. In JNCL, visual failure occurs at age 4-7 years, and blindness within a few years. Psychomotor deterioration becomes evident in the early school years, and seizures start at a mean age of 10 years. Extrapyramidal symptoms develop at age 12-15, and death usually occurs by the 3rd decade. Cardiac complications have not previously received much attention. In Menkes Textbook of Child Neurology 3rd ed, 1985, cardiac involvement is not mentioned among the various forms of NCL, classified according to age at onset: Infantile (Santavuori) 9-19 months; Late-infantile (Batten-Bielschowsky) 2-4 years; Variant (Batten) 5-7 years; Juvenile (Spielmeyer-Vogt) 4 years-puberty. To-date, 10 types of NCL are described caused by mutations in recessively inherited genes, 8 of which are characterized.