Breakthrough in dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is a type of dementia that shares symptoms of Alzheimer’s disease and Parkinson’s disease. A person with DLB might have symptoms including dementia, visual hallucinations, slow movement and stiff limbs. Like, those who have Parkinson’s disease people with dementia with Lewy bodies have dense round spots and wispy threads of alpha-synuclein protein in their brains. People with DLB can also show the signs of Alzheimer’s disease in their brains such as twisted tangles of tau protein and in some cases clumps of sticky amyloid-beta protein.

Until now, it has been unclear whether your genes might play a role in how likely you are to develop DLB. In a study that is the first of its kind, Alzheimer’s Society-supported researchers Dr Rita Guerreiro and Dr Jose Bras have discovered a group of genetic factors that increase the risk of having DLB. They propose that as many as 36% of cases in the sample studied might have been influenced by these and other, still to discovered, genetic risk factors.

The aim of this study was to discover any potential genetic factors that could change a person’s risk of developing DLB. Geneticists tackle this sort of question by looking at the genes of as large a group of people living with the disease as they can. The researchers took on the huge task of testing 8.3 million genetic factors in 5,778 people (1,324 people with DLB and 4,454 without) from 10 countries.

What were the results? 

The results were organised into what is called a ‘Manhattan plot’, a type of graph that resembles the densely packed New York skyline. Each ‘skyscraper’ in this graph represents a genetic marker that the researchers tested. The tallest represent the factors that are most strongly linked to DLB.

Dr Guerreiro said: 

‘These results offer us, for the first time, a way to start to differentiate DLB from Alzheimer’s and Parkinson’s from the most relevant perspective – their molecular basis.'

Drs Guerreiro and Bras discovered four genetic factors that are linked to people developing DLB. This finding has been welcomed as a breakthrough since it shows that DLB is a genetically unique disease. DLB will no longer be assumed to be caused by a mixture of the genetic risk factors for Alzheimer’s and Parkinson’s.

DLB has not been researched as much as Alzheimer’s disease and this study is a big step forward. It highlights our commitment to funding research to understand and treat all forms of dementia. Genetic factors like these can increase risk of developing DLB, but you can reduce the risk of developing dementia by making lifestyle changes such as staying active, keeping up social interactions and not smoking.