[Mutation analysis of amyloid precursor protein in early-onset familial Alzheimer's disease].

Recently, three different mutations have been found at codon 717 of the amyloid precursor protein (APP) gene, changing the native valine to isoleucine, phenylalanine and glycine in some familial Alzheimer's disease (FAD) kindreds. More recently, some other mutations have also been reported at codons 670 and 671 (double mutation), and codon 692. As analysis of coding region except exon 16 and 17 has been insufficient in previous reports, we analyzed entire coding region of the APP gene of 6 Japanese early-onset FAD kindreds using automated sequencer. Three FAD families showed known 717 Val to Ile mutation, whereas no novel mutations were detected.