NO ASSOCIATION BETWEEN THE K-VARIANT OF THE BUTYRYLCHOLINESTERASE GENE AND PATHOLOGICALLY CONFIRMED ALZHEIMERS-DISEASE

The polymorphic K variant of the butyrylcholinesterase (BCHE-K) gene r ecently has been demonstrated to have an elevated frequency in Alzheim er's disease (AD) patients carrying the epsilon 4 allele of the apolip oprotein (APO E) gene when compared with a control population. We ther efore genotyped a large series of pathologically confirmed AD patients and controls to confirm this association. We found no change in the f requency of this genetic variant, either in the AD group as a whole or in early- or late-onset patients when compared with age-matched contr ols. Stratification of these groups with reference to the APO E epsilo n 4 allele also showed no difference between AD and control groups. To determine if a biological effect were present, we also looked at seni le plaque and neurofibrillary tangle densities in the frontal, tempora l, parietal and occipital cortices in AD patients either carrying or n ot carrying a copy of the K variant. We found no difference in plaque or tangle load between these two groups in either the total, late-onse t or early-onset AD subjects. Stratification of the total AD group in terms of APO E epsilon 4 allele possession, and further comparison of plaque and tangle load between carriers and non-carriers of BCHE-K sti ll failed to disclose a relationship between BCHE-K and AD. We conclud e that in the population studied here there is no association between BCHE-K and AD, or that if such a relationship exists it is precluded b y another, as yet unknown factor.