Figure 2.

Fibroblasts from individuals with NPC1 disease show LysoTracker staining that significantly correlates with age of onset and disease severity. (a) LysoTracker level, measured as fold-change increase over background, is inversely correlated with the age of symptom onset. These age of onset data points included any NPC1-associated phenotypes, such as hepatosplenomegaly, jaundice and neurological abnormalities. (b) LysoTracker level also shows inverse correlation with the age of first neurological symptom, and this correlation is greater than that seen for any symptom onset. (c) LysoTracker level correlates with the age-adjusted neurological severity score (see “Materials and methods” section for score description). For all 3 graphs, each point represents a single NPC individual, and log₁₀-transformed values are presented and were used for statistical analyses. P values indicate significant correlation using Spearman’s correlation; lines were calculated using simple linear regression.