Disease progression in 38 NP-C patients with neurological disease. (A) Occurrence of disease symptoms over time (in years) was scored for each of the 38 patients (colored lines) individually with both, the NPC-cdb score (large graph) and the NIH clinical severity scale (Yanyanin et al., 2010, ; inset), each normalized to the age at neurological disease onset (x=0). Higher score values (y-axis) reflect higher number of symptoms. Standard deviations around mean values (reflecting the normal range) are represented by yellow clouds. (B) Examples for patients with particular types of disease progression. Top, steady disease course; center, rapid degenerative course; bottom, initial steady progression is followed by acceleration.