Evidence for Beta Amyloid 42: Causes of Alzheimer’s Disease

Explore the evidence, which spans scales from hereditary epidemiology to molecular structure, implicating Beta Amyloid 42 as a cause of Alzheimer’s disease. At The Emergent Universe, an online interactive science museum about emergence.

CSI: The Evidence

Evidence implicating small clusters of Beta Amyloid 42 comes from studies on many levels:

Family histories

Studies of family histories uncovered variants of Alzheimer’s that run in families. Molecular genetics studies later identified the disease-causing genetic mutations and showed that their effect is nearly always to increase production of Beta Amyloid 42, either alone or in combination with Beta Amyloid 40.


Studies show that Alzheimer’s patients with more small clusters of Beta Amyloid in their brains have more severe dementia.


Small clusters of Beta Amyloid 42 are toxic to neurons, more so than either Beta Amyloid 42 itself or Beta Amyloid 42 fibrils.


Beta Amyloid 42 and Beta Amyloid 40 are very similar molecules, yet a solution of Beta Amyloid 42 is significantly more toxic to neurons than a solution of Beta Amyloid 40. What is it about the molecular structure of Beta Amyloid 42 that makes this species more dangerous?