The London APP mutation (Val717Ile) associated with early shifting abilities and behavioral changes in two Italian families with early-onset Alzheimer's disease

Background/Aims: Mutations in the amyloid precursor protein gene were the first to be recognized as a cause of Alzheimer's disease (AD). Methods: We describe 2 Italian families showing the missense mutation in exon 17 of the amyloid precursor protein gene on chromosome 21 (Val717Ile), known as London mutation. Results: In 1 family, this mutation was responsible for AD in 3 out of 7 siblings and it is also present in a fourth sibling who has only shown signs of executive dysfunction so far. Two subjects of the other family with AD diagnosis were carriers of the same mutation. Conclusion: All AD subjects showed a cognitive profile characterized by early impairment in long-term memory, shifting abilities and affective symptoms beginning in the fifth decade of life.