A neurodegenerative disorder characterized by an excessive accumulation of lipofuscin in cells and tissues
Neuronal ceroid lipofuscinosis is a neurodegenerative disorder wherein there is an excess of lipofuscin in cells (especially neuronal cells) and tissues, such as liver, spleen, kidneys, and myocardium. Lipofuscin is a pigmented lipid granule. It is a residue of lysosomal digestion.
Neuronal ceroid lipofuscinosis is classified into ten types according to the associated gene:
- Type 1 – associated with PPT1 gene
- Type 2 – associated with TPP1 gene
- Type 3 – associated with CLN3 gene
- Type 4 – associated with CLN6 gene and DNAJC5 gene
- Type 5 – associated with CLN5 gene
- Type 6 – associated with CLN6 gene
- Type 7 – associated with MFSD8 gene
- Type 8 – associated with CLN8 gene
- Type 9 – associated with an unknown gene
- Type 10 – associated with CTSD gene
Most of these types are inherited in an autosomal recessive pattern. This means that the individual has two copies of the defective gene and therefore manifests symptoms associated with the disease. A carrier of the disease would have only one copy of the defective gene and therefore may not show symptoms.