New gene therapy technique could reverse Alzheimer’s

A huge breakthrough in the battle to find a cure for Alzheimer’s disease has been achieved, which could see the condition reversed in the future. Up until now, the only treatment options that have shown any improvement have only worked when symptoms are diagnosed early.

Scientists at the Massachusetts Institute of Technology (MIT) have found a way to render the gene responsible for Alzheimer’s disease harmless. By using a genetic snipping technique, APOE4, which causes amyloid beta proteins in the brain to build up, could be turned into APOE3.

The experiments were conducted using cells from dementia patients and could help to pave the way for better treatments for those with age-related brain diseases. Those with one copy of the APOE4 gene have double the risk of Alzheimer’s, while two copies increase the chances by 12 times.

It is this gene that tests look to detect when a diagnosis for Alzheimer’s is being sought. Approximately one in four people carry the variant of the gene and that is why Alzheimer’s is such a common condition, and a focus for much medical research.

Professor Li-Huei Tsai of MIT said: “APOE4 is by far the most significant risk gene for late-onset, sporadic Alzheimer's disease. However, despite that, there really has not been a whole lot of research done on it. We still don't have a very good idea of why APOE4 increases the disease risk.”

There are three variants of the APOE gene, known as 2, 3 and 4, and they are responsible for transporting fatty molecules, including cholesterol, into the lymph system and subsequently into the blood.

Most common among the general population is APOE3, which is present in 78 per cent of people and is considered healthy by scientists. The eight per cent of people who carry APOE2 see their risk of developing Alzheimer’s reduced by half.

It is those who have the APOE4 gene that need to worry about the condition, and this equates to around 14 per cent of people. Scientists do not know why those with the APOE4 gene have higher levels of amyloid proteins in the brain, but gene editing could be the answer to overcoming the issue.

The technique employed by the researchers harnessed pluripotent stem cells, which can be obtained from the skin, and turned them into three types of brain cells. These neurons, astrocytes and microglia were then used to replace the unwanted genes, which were cut out with bacteria that act as molecular scissors.

Alzheimer’s is the most common form of dementia, accounting for 62 per cent of diagnoses of the neurodegenerative condition in the UK. Most of those affected are aged 65 and over, meaning it is stripping many elderly people of their independence as they age.

Among the primary warning signs that a person is suffering from the disease are difficulty in remembering new information, disorientation, mood swings and suspicions about friends and family. Early diagnosis is seen as key to limiting the advance of the condition, for which there is currently no known cure.