Newly Identified Gene Variants May Increase Susceptibility to Tauopathies 

In a preliminary study released today, researchers identified gene variants that are associated with a susceptibility to developing tau deposits with age. It is known that the protein tau develops into tangles in the brains of people with Alzheimer disease (AD), but understand of factors that cause accumulation of tau to convert to formation of tangles remains lacking.

Paricipants in the study with certain gene variants on chromosomes 1 and 5 had a more tau in their brains than the those who had the more typical gene sequences in those regions. The gene variants were found in around 2 to 3% of participants, and those with the variants had about 10% higher tau levels than those without. 

There was no relationship between these new genetic markers and other genes that have previously been identified as related to AD risk, including the apolipoprotein E gene, or APOE. 

"These results are exciting, particularly since we know that tau accumulation is closely related to cognitive impairment in AD," said study author Vijay Ramanan, MD, PhD, of the Mayo Clinic in Rochester, Minn, and a member of the American Academy of Neurology. "Gaining a better sense of why some people are more susceptible or resistant to having tau deposits may help us better predict who will develop symptomatic disease, and hopefully better target individualized therapies for these patients." 

The study involved 754 people mean age 72, 87% of whom had no problems with memory or thinking skills. Brain scans were used to measure tau. 

"This suggests that the deposition of these tau proteins in the brain may be influenced by different inherited factors than the known genes that increase the risk of AD," Ramanan said. "This may give us additional avenues for discovery as we work to identify people at risk for this devastating disease and to develop new targets for therapies."