LINKAGE ANALYSIS OF LATE-INFANTILE NEURONAL CEROID-LIPOFUSCINOSIS

The neuronal ceroid-lipofuscinoses (NCL) are a group of neurodegenerat ive disorders with an autosomal-recessive pattern of inheritance. Ther e are 3 main categories of childhood NCL, namely, infantile, late-infa ntile, and juvenile NCL. These can be distinguished on the basis of ag e of onset, clinical course, and histopathology. A number of variant f orms of NCL have also been described, and these show symptoms intermed iary between the main classical forms. The genes for both the infantil e and juvenile forms of NCL have previously been mapped to chromosome areas 1p32 and 16p12, respectively. The gene for late-infantile NCL (L INCL), CLN2, has been excluded from both these loci, but its location is as yet unknown. Recently, CLN5, the gene for the Finnish variant fo rm of LINCL, was mapped to 13q21.1-32. Using the 3 microsatellite mark ers which were most tightly linked to CLN5, we have excluded CLN2 from this region using a subset of 17 families. Thus, CLN2 represents a fo urth distinct genetic locus involved in the pathogenesis of NCL. (C) 1 995 Wiley-Liss, Inc.