This gene makes you smart

In what could open up new therapeutic avenues for the prevention of Alzheimer's disease and other forms of dementia, scientists have now identified a gene that could play a role in making some people smarter than others.

People who have a variant of a longevity gene, called KLOTHO, have improved brain skills such as thinking, learning and memory regardless of their age, sex or whether they have a genetic risk factor for Alzheimer's disease, the study said.

"This shows the importance of genes that regulate the multiple aging processes involved in the maintenance of cognitive function," said Suzana Petanceska, programme director of division of neuroscience at National Institute of Aging in the US.

People who had one copy of a variant, or form, of the KLOTHO gene, called KL-VS, performed better on a battery of cognitive tests than participants who did not have it, regardless of age, sex or the presence of the apolipoprotein 4 gene, the main genetic risk factor for Alzheimer's disease.

The investigators tested a variety of cognitive skills, including learning, memory, and attention of more than 700 participants aged 52 to 85 years old as part of three studies.

The KLOTHO gene provides the blueprint for a protein made primarily by the cells of the kidney, placenta, small intestine and prostate.

A shortened version of the protein can circulate through the blood system.

Blood tests showed that participants who had one copy of the KL-VS variant also had higher levels of circulating klotho protein.

The levels decreased with age.

The age-related decrease in circulating levels of klotho protein may have caused some of the decline in performance on the cognitive tests, researchers speculated.

The study appeared in the journal Cell Reports.