Positional cloning of the CLN5 gene defective in the Finnish variant of the LINCL

Neuronal ceroid lipofuscinoses (NCLs) in children are progressive encephalo pathies inherited as autosomal recessive traits. Progressive neuronal damag e leads to psychomotor deterioration, visual failure, seizures, and finally to premature death. Based on the clinical course of the disease, the child hood forms can be divided into several subtypes. A variant form of the late infantile NCL (vLINCL), characterized by mental retardation, visual failur e, ataxia, myoclonia, and death between the ages of 13 and 30 years, is pre valent in Finland. Information on ancient recombination events in disease a lleles rising from this isolated population provided an efficient tool for refining the initial assignment of the CLN5 locus. Here we describe the ste ps resulting in the identification of the novel gene, defective in vLINCL. (C) 1999 Academic Press.