GENETIC-HETEROGENEITY IN NEURONAL CEROID-LIPOFUSCINOSIS (NCL) - EVIDENCE THAT THE LATE-INFANTILE SUBTYPE (JANSKY-BIELSCHOWSKY DISEASE CLN2)IS NOT AN ALLELIC FORM OF THE JUVENILE OR INFANTILE SUBTYPES

The neuronal ceroid lipofuscinoses (NCLs) are a group of inherited neu rodegenerative disorders characterized by the accumulation of autofluo rescent lipopigment in neurons and other cell types. Inheritance is au tosomal recessive. Three main childhood subtypes are recognized: infan tile (Haltia-Santavuori disease; MIM 256743), late infantile (Jansky-B ielschowsky disease; MIM 204500), and juvenile (Spielmeyer-Sjogren-Vog t, or Batten, disease; MIM 204200). The gene loci for the juvenile (CL N3) and infantile (CLN1) types have been mapped to human chromosomes 1 6p and lp, respectively, by linkage analysis. Linkage analysis of 25 f amilies segregating for late-infantile NCL has excluded these regions as the site of this disease locus (CLN2). The three childhood subtypes of NCL therefore arise from mutations at distinct loci.