( orted ages of onset ranging from 4 to m...)U of MN researchers identify ataxia gene

Now that researchers have identified the specific mutation that causes SCA5, testing of patients at risk of developing this disease is possible before any symptoms appear. The availability of predictive testing allows people with a family history of the disease to determine whether they will develop the disease and whether their children are at risk of inheriting the mutation. In addition, the prognoses of the different types of ataxias vary greatly, so identifying the specific type of ataxia provides patients with a more accurate picture of what the future holds.

Ranum added: "Finding the SCA5 mutation in Lincoln's family makes it possible to test Lincoln's DNA ?if it becomes available ?to unequivocally determine if he carried the mutation and had or would have developed the disease." Biographical texts of Lincoln include descriptions of his uncoordinated and uneven gait, suggesting the possibility that he showed early features of the disease.

Ranum started this historical and scientific journey more than a decade ago. She and her colleagues John Day, M.D., Ph.D., University of Minnesota, and Larry Schut, M.D., CentraCare Clinic in St. Cloud, Minn., examined and collected DNA samples from more than 300 Lincoln family members who live across the country, tracking descendants from two major branches of the family.