A team of Italian doctors have recently made a discovery that they believe may lead to a new treatment for Alzheimer’s disease. Alzheimer’s disease is a neurodegenerative condition that appears mostly in people over the age of 60, slowly destroying memory, thinking skills, and eventually the ability to carry out even simple tasks. A new gene mutation has been discovered that, when inherited from both parents, is found to cause Alzheimer's disease but, when only one copy is inherited, may in fact provide protection from the disease. Neurologist, Fabrizio Tagliavini, from the Carlo Besta National Neurological Institute in Milan uncovered the mutation in a patient showing early signs of Alzheimer’s disease who lacked mutations in other genes associated with this form of the disease. Tagliavini believes that Alzheimer’s could be treated by the recreation of this single copy condition with a drug.
It is believed that the symptoms of Alzheimer’s disease are caused by clumps of proteins in the brain which block neurons from communicating with each other, and thus creating memory and speech difficulties. This particular gene that has recently been discovered, called APP, produces a protein called A-beta which sticks together and forms these clumps in the brain.
This mutation is considered to be particularly interesting as all previously identified mutations that cause early onset Alzheimer’s are dominant - a single copy is enough to cause the disease. In order to illustrate this difference, normal and mutant forms of the protein were mixed. The resulting mixture clumped far less often than either mutant protein or normal protein alone. This explains why the patient found with two copies of mutant APP showed signs of the disease, whereas his older relatives, all with only one copy of the mutation, were able to stave off Alzheimer’s. If a synthetic protein is used to imitate this, Tagliavini believes that a new way of treating the disease could be offered to sufferers with two copies of the APP mutation, with only a six unit long protein required to prevent aggregating of clumps.
Tagliavini admits, though, that more conclusive testing needs to occur before this therapy could be applied. However according to Alzheimer’s expert at Harvard University, Rudolph Tanzi, as it is the first recessive mutation discovered with regards to Alzheimer’s, there is no doubt Tagliavini’s team’s work is “pretty exciting from a genetic standpoint.”
Reference:
http://www.newscientist.com/article/dn16750-paradoxical-gene-causes-and-protects-against-alzheimers.html
Sarah Cowley 41756962
