A type of lysosomal storage disease
- Fibroblast culture to test for impaired LDL-cholesterol trafficking.
- Filipin staining: accumulated free cholesterol.
- Impaired LDL-induced cholesterol ester formation.
- A variant biochemical form exists
Niemann-Pick disease type C: gene= NPC1 at 18q11 or NPC2 14q
Type A: Infantile, severe, cherry red macula, lungs are also involved
Type B: Massive hepatomegaly, splenomegaly. No neurological involvement.
Type C and D: Adult form (adolescent to adult). See below.
- Cortical (Cognitive, psychiatric and seizures)
- Deep brain (cerebellar ataxia, dysarthria, vertical supranuclear ophthalmoplegia, deafness, dysphagia, cataplexy, pyramidal syndrome, movement disorder/dystonia/myoclonic jerks)
Visceral (hepatomegaly, splenomegaly) involvement.
Findings on investigations:
MRI in Type C:
- Normal initially
- Atrophy corresponding to the clinical syndrome i.e. Frontal lobes, corpus callosum, brainstem, cerebellum,
EEG: Generalised slowing
Foam cells (marcophages with abundant vacuolated cytoplasm) in bone marrow, spleen, lymph nodes
Brain (types A,C): atrophy, severe gliosis, neurons are enlarged with abundant cytoplasm and small vacuoles.