CLINICAL AND MAGNETIC-RESONANCE-IMAGING FINDINGS IN BATTEN-DISEASE - ANALYSIS OF THE MAJOR MUTATION (1.02-KB DELETION)

A total of 36 patients with Batten disease (juvenile-onset neuronal ce roid lipofuscinosis), homozygous or heterozygous for the major mutatio n, a 1.02-kb deletion, in the CLN3 gene, were studied to relate their genotype to their clinical phenotype. The onset of visual failure and epilepsy was highly concordant in both groups. Great inter- and intraf amilial heterogeneity was demonstrated in the development of mental an d physical handicap and in magnetic resonance imaging findings among b oth homozygous and heterozygous patients. The 1.02-kb deletion in homo zygous form was always associated with mental and physical handicap, w hereas the heterozygous phenotype could be extremely benign without af fecting the intellectual level of the patient. Our data suggest that g enetic background, modifying genes, and environmental factors all infl uence the final phenotype of Batten disease.