[Absence of a connection between Alzheimer's disease and complement markers]

The hypothesis of a linkage between Alzheimer's disease (AD) (presenile dementia) and the complement components C2, C4, Bf linked to the Major Histocompatibility Complex has been investigated in a large family originating from Calabria, in which AD is transmitted as an autosomal dominant monogenic mendelian trait. The analysis of complotypes of 33 members of a pedigree, from which 10 individuals are affected, allowed to demonstrate that there wasn't any linkage between AD and those markers. Furthermore, no complete or partial deficiency in the C2, C4, Bf components has been observed in affected patients.