The phenotypes of 10 Finnish juvenile neuronal ceroid lipofuscinosis (JNCL; late-onset Batten disease) patients were correlated with the genotypes in a study at Helsinki University, Finland; and the Rayne Institute, University College, London, UK. JNCL is manifested as three phenotypes: classic, delayed classic, and protracted JNCL, with mainly ocular symptoms and slower mental and motor decline. All are compound heterozygotes for 5 rare mutations and the major 1.02-kb deletion in the CLN3 gene. A novel deletion of exons 10 through 13 was present in 6 patients in 3 families, all having a similar clinical course. The development of blindness showed the greatest familial heterogeneity, from 6 to 15 years. 
COMMENT. Late-onset Batten disease (JNCL) is an autosomal recessive, progressive encephalopathy of childhood, with ceroid and lipofuscinlike material in neural and nonneural tissues. The gene is on chromosome 16pl 1.2-12.1.