Risk factors for Alzheimer's include:-

Alzheimer disease is associated with deposition of amyloid beta(AB) plaque which is produce from amyloid associated protein(APP) which is coded from gene present on chromosome 21. This is called pre senile dementia or premature Alzheimer. Noonan syndrome : defect in gene PTPN11, KRAS, SOS1 leading to defect in signaling protein. Patient have pulmonary valve stenosis, VSD or hyperophic cardiomyopathy.