Application of genetic paradigms to Alzheimer's disease (AD) has led to confirmation that
genetic factors play a role in this disease. Additionally, researchers now understand that AD
is genetically heterogeneous and that some genetic isoforms appear to have similar or
related biochemical consequences. Genetic epidemiologic studies indicate that first-degree
relatives of AD probands have an age-dependent risk for AD≅ 38% by age 90 years (range
10% to 50%). This incidence strongly suggests that transmission may be more complicated …