Gene contributes to Alzheimer’s risk

Scientists have identified a gene that increases the risk for late-onset Alzheimer’s and provides another clue into the complex mind-robbing disease.

The gene -- SORL1 -- stands out because it’s been tested in four ethnic groups and a form of it seems to confer a risk in all of them -- including North Europeans, Caribbean Latinos, African Americans and Israeli Arabs.

The gene’s normal role is to shuttle proteins through a cellular pathway and, in particular, moves an Alzheimer’s protein called APP through its normal route. But a specific form of the SORL1 gene mucks up this machinery and results in an accumulation of the sticky protein called amyloid that plays a major role in the disease. Sticky amyloid appears to damage communication between brain cells.

The researchers, at Toronto University, say having this particular form of SORL1 increases risk by about 20%.

The study is being published in the February issue of Nature Genetics and was released Tuesday online.