Scientists have claimed an important breakthrough in the battle against Alzheimer’s after neutralising the most significant gene responsible for the disease for the first time.

A team in California successfully identified the protein associated with the high-risk apoE4 gene and then managed to prevent it damaging human neuron cells.

The study could open the door to a potential new drug capable of halting the disease, however the researchers have urged caution because so far their compound has only been tried on collections of cells in a laboratory.

Having one copy of the apoE4 gene more than doubles a person’s likelihood of developing Alzheimer’s disease, whereas having two copies increases the risk 12-fold.

Previous studies have indicated that roughly one in four people carry the gene.

In human neurons, misshapen apoE4 protein cannot function properly and is broken down into disease-causing fragments in the cells.

This results in several of the problems commonly found in Alzheimer’s disease, which affects 7.1 per cent of Britons above the age of 65, including the accumulation of protein tau and amyloid peptides.

The team at Gladstones Institutes set out to establish whether the presence of the protein was causing the damage, or whether a lack of it was to blame.