GENOME-WIDE SEARCH FOR CLN2, THE GENE CAUSING LATE-INFANTILE NEURONALCEROID-LIPOFUSCINOSIS (LNCL)

The loci for the juvenile (CLN3) and infantile (CLN1) neuronal ceroid lipofuscinosis (NCL) types have been mapped by genetic linkage analysi s to chromosome arms 16p and 1p, respectively, The late-infantile defe ct CLN2 has not yet been mapped, although linkage analysis with tightl y linked markers excludes it from both the JNCL and INCL loci, We have initiated a genome-wide search for the LNCL gene, taking advantage of the large collection of highly polymorphic markers that has been deve loped through the Human Genome Initiative. The high degree of heterozy gosity of these markers makes it feasible to carry out successful link age analysis in small nuclear families, such as found in LNCL, Our cur rent collection of LNCL pedigrees includes 19 US families and 11 Costa Rican families. To date, we have completed typing with over 50 marker s on chromosomes 2, 9, 13, and 18-22. The results of this analysis for mally exclude about 10% of the human genome as the location of the LNC L gene. (C) 1995 Wiley-Liss, Inc.