Alzheimer's disease (AD) is a degenerative disorder of the central nervous system which causes progressive cognitive decline during mid to late adult life. The primary causes of AD have not yet been identified. Mutated genes have been located on chromosome 21, 14 and 1, leading to the early onset familial form of the disease (EOFAD). Preliminary results reported in this paper suggest that the Acylphosphatase (AcPase) alteration seems to occur only in the fibroblasts from patients with the familial form of AD linked to mutations of the presenilin genes. Thus it is possible that a pathway exists whereby dysfunctional presenilin proteins lead to increased amyloid beta-protein production and that AcPase could function in this pathway through a disruption of calcium homeostasis or an impairment of energy metabolism.