CLASSIFICATION OF THE NEURONAL CEROID-LIPOFUSCINOSES - EXPANSION OF THE ATYPICAL FORMS

The neuronal ceroid-lipofuscinoses (NCL) are a group of different gene tic diseases, The major types of NCL are expressed by six forms which represent different clinicopathologic and genetic forms, These are CLN -1, Infantile; CLN-2, Late Infantile; CLN-3, Juvenile; CLN-4, Adult-Re cessive; CLN-5, Adult Dominant; and CLN-6, Early Juvenile, The distinc tion between CLN-4 and CLN-5 is still disputatious. CLN-6 has been cal led CLN-5, A seventh classification of NCL represents from 12 to 20% o f those afflicted, This group consists of an extensive array of atypic al types of ceroid-lipofuscin accumulation in the secondary lysosomes of neurons and cells of other tissues (e.g., skin, conjunctiva, and ly mphocytes) or by presumed clinical and genetic relationships, The auth ors have identified 15 atypical subtypes of NCL. These as a group are here described as a seventh form, Further biochemical, molecular, and genetic studies will identify more precisely the phenotypic and genoty pic expression of these ''minor'' forms of NCL. (C) 1995 Wiley-Liss, I nc.