The majority of cases are a result of mutations in the TPP1 gene, however mutations in the CLN5, CLN6, CLN8, MFSD8, and PPT1 genes also account for a small number of cases. These mutations result in reduced activity of peptidase enzymes, particularly affecting lysosomes, but other mutations can affect protein catabolism in white blood cells, fibroblasts, and chorionic villi. The reduced function of these enzymes results in insufficient or incomplete breakdown of proteins, consequently resulting in the buildup of lipopigments in the lysosome. Though the accumulation of lipopigments occurs throughout the body, neurons are especially vulnerable to damage by lipopigment aggregation; a ubiquitous accumulation in lipopigments occurs in neurons, primarily concentrated in the cerebral and cerebellar cortices. This accumulation results in atrophy in these regions of the brain, and cause the pathogenesis of signs and symptoms of<unk> . Currently, it is unclear what mechanism in relation to enzyme activity is responsible for the buildup of lipoproteins.
Jansky–Bielschowsky disease
Camurati–Engelmann disease
Achondrogenesis type 2
Achondrogenesis type 1B
Hermansky–Pudlak syndrome
Metaphyseal chondrodysplasia Schmid type
Jansen's metaphyseal chondrodysplasia
Keppen–Lubinsky syndrome