[Absence of a close linkage between Alzheimer's disease and the polymorphic probe coding for superoxide dismutase 1].

The hypothesis of a tight linkage between Alzheimer's disease (AD), a presenile dementia, and the probe coding for superoxide dismutase 1 (SOD 1), located on chromosome 21 at 21q22, has been investigated in a large family originating from Calabria, in which AD is transmitted as an autosomal dominant mendelian trait. Analysis of the Msp I restriction polymorphism, after molecular hybridization with the probe of DNAs coming from 22 subjects of the pedigree, allowed to the demonstrate that there wasn't any tight linkage between AD and the marker studied.