Pathogenic mutations have been identified in exons 16 and 17 of the beta-amyloid precursor protein (APP) gene in some cases of early onset Alzheimer's disease. Screening of these exons in a number of familial and sporadic cases of Alzheimer's disease in Spain, resulted in the identification of a novel silent variant at codon 711 whose relevance to the AD pathogenesis remains unclear. The 708 variant was also detected in one of normal controls.