A FE65 polymorphism associated with risk of developing sporadic late-onset alzheimer's disease but not with Abeta loading in brains.

The FE65 protein was previously described interacting with amyloid protein precursor (APP) and mediating its internalization. Hu et al. (Hum. Genet., 103 (1998) 295) recently reported that a deletion polymorphism in intron 13 of the FE65 gene may be protective for sporadic Alzheimer's disease (AD) forms and suggested that this deletion may modify splicing between exon 13 and 14 (the two exons encoding the interaction domain of FE65 with APP). We tested the impact of this polymorphism in 646 controls and 639 sporadic AD cases. We were only able to detect a protective effect of the deletion in the population over 75 years (odds ratio = 0.53, 95% confidence interval (0.35-0.82), P= 0.002). Furthermore, no association of this polymorphism with Abeta40, Abeta42(43) and total Abeta loads were detected in 74 AD brains, although, we could expect that this deletion was associated with modifications of the APP metabolism. In conclusion, the FE65 gene may be a minor genetic determinant only for sporadic late-onset AD forms, although, we cannot conclude that this impact is mediated by a modulation of the APP process and/or Abeta peptide deposition.