Alzheimer disease (AD) is a complex neurodegenerative pathology that is characterized by a cognitive decline. Its causes and mechanisms are still largely unknown. It has been suggested that both genetic and life exposure factors can contribute to AD development. There are also evidences that chromosomal alterations can be related to this disease. So far, there is not a precise diagnosis for AD, which is given only after the exclusion of other dementia by clinical and neurological examination. The possible association of AD with chromosomal alterations and the easy access of classical cytogenetics analysis are important aspects to consider, given the difficulties in diagnosis. Due to the lack of similar studies in Brazil and the increasing number of AD cases in the state of Amazonas, the aim of this study was to investigate the presence of chromosomal alterations in patients diagnosed with AD in Manaus, Amazonas, Brazil. Peripheral blood lymphocytes of twelve patients and twelve healthy individuals with the same age were analyzed using conventional karyotyping. All AD patients presented cells with autosomal aneuploidy, while no chromosomal alterations were found in the age-matched controls. Also, rare events of double and multiple aneuploidies are being reported in association with AD for the first time. Our results corroborate that the increase in the frequencies of aneuploidies is not related to the aging process itself, but it might be associated to the disease development. However, no chromosomes were preferentially affected in all AD patients, and no consistent karyotype pattern for AD lymphocytes was found. Therefore, our results do not support the use of standard cytogenetics as a tool for AD diagnosis. Future studies are necessary to understand better the association between chromosomal alterations and AD.

Alzheimer's disease (AD) has as its main characteristic the deterioration of cerebral functions. Its etiology is still complex and undefined despite the progress made in understanding its neurological, infectious, biochemical, genetic and cytogenetic mechanisms. Considering this, the aim of this study was to investigate the presence of chromosomal alterations in the peripheral blood lymphocytes, and to verify if there was a high frequency of these alterations in patients diagnosed with AD at the University Hospital GetúLio Vargas Outpatient Clinic Araújo Lima in Manaus, Amazonas, Brazil. Among the nine patients in the AD group, only one patient did not have metaphases with chromosomal alterations (2n = 46,XX), while eight patients with AD showed numerical chromosomal alterations, classified as X chromosome aneupLoidy (2n = 45,X) and double aneupLoidy (2n = 44,X,-X,-10; 2n = 44,X,-X,-13 and 2n = 44,X,-X,-21). In the control group, no chromosomal changes were found in the karyotypes of these individuals. Therefore, the karyotypes of patients with AD undergo chromosomal alterations at different levels. These findings are being described for the first time in the population of Amazonas, and they highlight the importance of the inclusion of cytogenetic investigations in the routine management of patients with AD.