APP and early-onset autosomal dominant Alzheimer disease: Brain lipid homeostasis is an essential component for the emergence of neurodegenerative diseases, e.g., Alzheimer ́s disease (AD): the cleavage of the amyloid-precursor-protein (APP), that results in the cerebral accumulation of the neurotoxic amyloid -β(Aβ) to senile Aβ plaques, one of the characteristic hallmarks of AD, takes place in the biological membranes, since APP is a type I transmembrane protein [51].