The juvenile form of the disease (onset age 4-8 years with visual loss) is usually caused by mutations in the CLN3 gene, but some cases have been shown to be due to specific mutations in the CLN1 or CLN2 genes, which are usually associated with NCL with onset in infancy or late infancy, respectively.
Neuronal ceroid lipofuscinoses (NCL) comprise the most common group of childhood encephalopathies caused by mutations in eight genetic loci, CLN1-CLN8.
The purpose of this study was to compare the in vivo 1.5-T 1H magnetic resonance (MR) and ex vivo 14.3-T high-resolution (HR) magic angle spinning (MAS) 1H MR brain spectra of patients with infantile (CLN1) and juvenile (CLN3) types of NCL, to obtain detailed information about the alterations in the neuronal metabolite profiles in these diseases and to test the suitability of the ex vivo HR MAS (1)H MRS technique in analysis of autopsy brain tissue.
In five of the eight NCL variants distinguished at present, genes associated with the disease process have been isolated and characterized (CLN1, CLN2, CLN3, CLN5, CLN8).
The lysosomal storage of lipofuscins is the common pathological feature that characterizes the infantile, late-infantile, juvenile (Batten's disease), and Finnish-variant neuronal ceroid lipofuscinosis (INCL, LINCL, JNCL and FNCL), which are due to mutations in the genes CLN1, CLN2, CLN3, and CLN5, respectively.
We determined that the mutations 223A --> G and 451C --> T in CLN1, T523-1G --> C, and 636 C --> T in CLN2, and deletion of a 1.02-kb genomic fragment in CLN3 are the five common mutations for NCL.
We have examined mRNA levels of the CLN1, CLN2, and CLN3 genes, which are associated with the infantile, late infantile, and juvenile forms of NCL in 64 different human tissues, and have grouped the results into gastrointestinal tract, central nervous system, glandular/secretory, muscle, and carcinoma tissue types. mRNA levels for CLN3 are highest in gastrointestinal tissue and are also high in glandular/secretory tissue, whereas mRNA levels for CLN1 and CLN2 do not appear to be preferentially elevated in any tissue type.
The infantile form of neuronal ceroid lipofuscinosis (INCL; CLN1) is the earliest onset form of the neuronal ceroid lipofuscinoses (NCL), a group of progressive encephalopathies of children.