Genotype-phenotype analyses of classic neuronal ceroid lipofuscinosis (NCLs): genetic predictions from clinical and pathological findings.

Objective: Genotype-phenotype associations were studied in 517 subjects clinically affected by classical neuronal ceroid lipofuscinosis (NCL).

Methods: Genetic loci CLN1-3 were analyzed in regard to age of onset, initial neurological symptoms, and electron microscope (EM) profiles.

Results: The most common initial symptom leading to a clinical evaluation was developmental delay (30%) in NCL1, seizures (42.