Adult type of neuronal ceroid lipofuscinosis.

Adult neuronal ceroid lipofuscinosis (NCL), also called Kufs' disease, is clinically distinct from the other NCLs. It is a rare condition which is difficult to diagnose. More than 50% of the reported cases of Kufs' disease are not adult NCL and correspond very likely to a heterogeneous spectrum of lipidoses. Various clinical and genetic phenotypes of adult NCL may be recognized, one featuring a progressive myoclonus epilepsy. It is important to stress that in contradistinction with the juvenile and protracted juvenile NCL, there is no pigmentary degeneration of the retina. Adult NCL is an autosomal recessive condition but two families have an autosomal dominant inheritance. The diagnosis of adult NCL may be suggested by a careful evaluation of skin, rectal or brain biopsies with the electron microscope but the diagnosis is fraught with many hazards. The pathogenetic defect lies probably in the intracellular processing of lysosomal and perhaps of Golgi membranes. The recent discovery of subunit c of mitochondrial adenosine triphosphate synthase in the stored cytosomes represents certainly an interesting prospect for future developments.