Atypical juvenile neuronal ceroid lipofuscinosis: A report of three cases.

The diagnosis of juvenile neuronal ceroid lipofuscinosis (JNCL) is usually based on age of onset, initial clinical symptoms, clinical progression, and pathologic findings. Our cases manifested atypical clinical symptomatology and/or pathologic findings and therefore, represent variant forms of JNCL. Case 1 and 2 presented with slow developmental regression from the age of 4 years and became blind and wheelchair bound at around 8 years. Pathologic finding of lymphocytes showed fingerprint inclusion which was consistent with JNCL. Mutational analysis was positive for CLN5 which usually presents as variant late infantile NCL (LINCL) and more common in Finnish population. Case 3 presented with progressive visual loss from the age of 8 years. Clinical symptomatology and age of onset were similar to that of JNCL but was found to have low palmitoyl protein thioesterase, granular inclusion body, and CLN1 mutation, thus representing milder form of INCL. These three cases demonstrated phenotypic-genotypic variations. Pertinent issues relating diagnostic difficulties, ophthalmologic, neuroradiological, and laboratory aspects are discussed.