Alzheimer’s risk microprotein in the brain identified

The mutation of a specific microprotein in the brain significantly raises the risk of developing Alzheimer’s disease later in life, scientists have found. Researchers from the University of Southern California (USC) in Los Angeles discovered that when the SHMOOSE protein was deactivated, the chances of getting the condition increased by 20 to 50 per cent.

Despite research being carried out all over the world, it’s not entirely clear what causes Alzheimer’s. It’s thought the abnormal build-up of proteins in the brain is significant, but what leads to them is far from certain. Ageing, a sedentary lifestyle and a family history of dementia are all contributing factors, although there’s still a lot to learn about the condition.

Better understanding of Alzheimer’s is key to developing new treatments, so identifying the SHMOOSE protein could have a big impact moving forward. In the past, research has focused on standard-sized proteins, with around 20,000 having been investigated. Now, scientists have moved onto hundreds of thousands of smaller proteins to look for causes.

The genetic data of more than 8,000 individuals was analysed in this latest research to find any connections to Alzheimer’s. They discovered that a mutation in one gene deactivated the SHMOOSE protein resulting in an increased risk of the disease , which is the most common form of dementia.

While the new information buildson what’s already known about the neurodegenerative condition, it’s not clear why the microprotein, gene and risk are all linked. SHMOOSE is involved with producing energy in mitochondria, which may be the next line of inquiry. One hypothesis is that an energy deficit in the cells could reduce their protective coating.

Dr Pinchas Cohen, dean of the USC Leonard Davis School of Gerontology, said: “This discovery opens exciting new directions for developing precision medicine-based therapies for Alzheimer's disease. Administration of SHMOOSE analogs in individuals who carry the mutation... may prove to have a benefit in neurodegenerative and other diseases of ageing.”

SHMOOSE is the first microprotein to be associated with such an increased risk of developing Alzheimer’s. Genes that have been linked to the condition in the past have all upped the risk by less than ten per cent. The strongest link to have been discovered is gene APOE4, with two copies of it in an individual raising the risk by 60 per cent.

Some 70 per cent of people in care homes have dementia or another type of severe memory issue, according to the Alzheimer’s Society. It’s predicted that by 2040, 1.6 million individuals will be living with the condition in the UK. This highlights the need for a cure to be found, as the only treatments available at present slow it down if a diagnosis is established early enough.