Alzheimer's and diabetes may be connected by a single gene

A single gene connected to Alzheimer's disease may also link to diabetes, researchers at The City College of New York believe. Though an early finding, the researchers believe it could offer scientists new drug targets and other treatment options they haven't had before for both diseases.

Their study considered how the human "amyloid precursor protein" (APP) gene is a factor in both conditions. And they started based on some circumstantial evidence. The APP gene, which processes amyloid precursor protein, appears in Alzheimer's disease patients where the condition runs in families. Similarly, they also know that people with diabetes appear to have a greater risk of also developing Alzheimer's.

Studies of the APL-1 gene in the Caenorhabditis elegans (C.elegans) worm, which is similar to the APP gene in people, helped them make the connection between the two. What they found: A mutated APL-1 gene slowed the worms' development, and scientists determined that it specifically blocked the insulin pathway, leading to their hypothesis that the human variation of the gene affects both Alzheimer's and diabetes. Interestingly, mutating the insulin pathway even more helped reverse the mutation of the APL-1 (APP equivalent) gene mutation.

This is an early finding, of course, showing only one possible link to both diseases. And there are plenty of variables. For example, the team must still determine how the amyloid precursor protein intersects with signal neurons and other cells along the insulin pathway. Further testing over many years will be necessary to make sure the discovery bears out in people. But it is a promising first step. Further details are published in the journal Genetics.

- here's the release