Alzheimer’s disease (AD) is a multifactorial disease with genetic (70%) and environmental
(30%) causes. Among the genetic factors are genes associated with a family history of the disease
(familial AD, FAD) and sporadic AD (SAD). The genes: APP (amyloid precursor protein), PSEN1
(Presenilin 1) and PSEN2 (Presenilin 2) are responsible for the presence of FAD. The APOE gene is
responsible for the sporadic form of the disease. Other molecular factors related to the immunological
cause (TREM2) of the disease are a disorder of the lipid (ABCA1, ABCA7) or biothiol (MTHFD1) metabolism
and of the transport of metabolites (BIN1). Currently, it is believed that APOE is a risk factor
for both SAD and late-onset FAD.
The pathomechanism of AD is most commonly explained as based on the amyloid cascade theory. This theory is related
to the FAD, although there are reports indicating the probability of its occurrence in the SAD. It seems that the excessive
deposition of β-amyloid (Aβ) peptides and intracellular neurofibrillary tangles of tau protein hyperphosphorylated forms
contribute to the damage of both DNA and RNA. Furthermore, it is believed that RNA-interference can affect both the
level of pathological proteins (Aβ, tau protein) and the onset and progress of AD.
It seems that a complete understanding of both FAD and SAD pathogenesis may contribute to the search for earlier clinical
diagnosis and to an understanding of later occurrence of the disease, which may help modify its course and affect more
effective therapy of this incurable neurological disease.