Martha M. González-González

Background/Objectives: Several genetic factors are related to the risk of Alzheimer’s disease (AD) and the response to cholinesterase inhibitors (ChEIs) (donepezil, galantamine, and rivastigmine) or memantine. However, findings have been controversial, and, to the best of our knowledge, admixed populations have not been previously evaluated. We aimed to determine the impact of genetic and non-genetic factors on the risk of AD and the short-term response to ChEIs and memantine in patients with AD from Mexico. Methods: This study included 117 patients from two specialty hospitals in Mexico City, Mexico. We evaluated cognitive performance via clinical evaluations and neuropsychological tests. Nineteen variants in ABCB1, ACHE, APOE, BCHE, CHAT, CYP2D6, CYP3A5, CHRNA7, NR1I2, and POR were assessed through TaqMan assays or PCR. Results: Minor alleles of the ABCB1 rs1045642, ACHE rs17884589, and CHAT rs2177370 and rs3793790 variants were associated with the risk of AD; meanwhile, CHRNA7 rs6494223 and CYP3A5 rs776746 were identified as low-risk variants in AD. BCHE rs1803274 was associated with worse cognitive functioning. None of the genetic and non-genetic factors studied were associated with the response to pharmacological treatment. Conclusions: We identified potential genetic variants related to the risk of AD; meanwhile, no factor was observed to impact the response to pharmacological therapy in patients with AD from Mexico.

Aging involves a variety of cognitive and language changes. Word association norms (WANs), which describe the first word people say or write after reading or hearing a stimulus word, reflect the organization of semantic knowledge. The aim of this study was to create a WAN corpus for Mexican older adults, with 114 participants responding to 117 nouns. The results of eight measures of word-word relationships showed that participants generated an average of 38.14 different response words for each stimulus word. Of these responses, 41.88% were of high associative strength and 20.70% were idiosyncratic, demonstrating the uniqueness of responses of older adults. In addition, we compared their responses to a corpus for younger adults (Barrón-Martínez & Arias-Trejo, 2014). A qualitative analysis categorizing the responses into syntagmatic and paradigmatic types showed that the older group tended to respond with words from a different grammatical class. Responses of the younger adults were also more cohesive and less varied than those of the older group. This corpus for older adults is an essential resource for evaluating age-related changes in semantic memory, and it provides a point of comparison for responses from people with neurodegenerative diseases.