APP, the gene responsible for making beta-amyloid in the brain, may be able to reshuffle its own DNA, scientists from Sanford Burnham Prebys Medical Discovery Institute in California have claimed. This development could explain why most drugs to treat Alzheimer’s, which are designed to remove beta-amyloid protein build-ups in the brain, have proven ineffective in clinical trials.

The scientists found ten times more APP variants in the brain cells of those with Alzheimer’s than those without, with these variants able to produce a number of toxic proteins, in addition to beta-amyloid. These would be missed by drugs specifically designed to remove only beta-amyloid from the brain.

It is as yet unclear why APP can morph into different forms. The California scientists have speculated that it could be to let it produce a wider range of signalling proteins.

Jerold Chun, one of the researchers, speculated that HIV medication which blocks reverse transcriptases could also be useful to prevent Alzheimer’s given this new finding. While clinical trials would be needed to prove this link, Chun noted: “The great thing about these drugs is that many of them have been used in HIV patients for decades, so we already know they’re safe.”