Recent biochemical and genetic advances in our understanding of Batten's disease (ceroid-lipofuscinosis).
Protein is the major component of the intra-lysosomal storage material which characteristically accumulates in Batten's disease. In the late-infantile, juvenile and adult forms of the disease, and in a form affecting sheep, this protein is principally composed of a single polypeptide, subunit c of mitochondrial ATP synthase. Subunit c is not stored in the infantile form of Batten's disease, supporting recent genetic data which suggest this is a distinct disease. Nor is subunit c found in storage material within other lysosomal storage diseases or in lipofuscin of old age. Subunit c storage, therefore, is specific for the later-onset forms of Batten's disease and indeed may be central to their aetiology.