Down syndrome increases risk of dementia, diabetes and autism IRVINE, Calif., Jan. 27 (UPI) -- People with Down syndrome have higher susceptibility to other conditions such as dementia, researchers in the United States and Argentina found. Pablo Helguera, Jaqueline Seiglie and Michael Hanna of the University of California, Irvine; Jose Rodriguez of the University of California, Los Angeles; and Gustavo Helguera of Argentina's University of Buenos Aires revealed some of the underlying neural factors that explain why people with Down syndrome were more susceptible to Alzheimer's disease, diabetes and autistic spectrum disorders. Busciglio and colleagues analyzed the cellular and molecular mechanisms leading to oxidative stress and mitochondrial dysfunction in Down syndrome individuals. The researchers found this breakdown in energy metabolism within brain cells contributes to the higher probability of these other conditions. Down syndrome occurs when a person has 47 chromosomes instead of the usual 46. Estimates of the researchers suggested 25 percent or more of individuals age 35 and older with Down syndrome showed signs of Alzheimer's-type dementia and this percentage increases with age. The incidence of Alzheimer's disease in people with Down syndrome is roughly three to five times greater than in the general population, the study said. The findings were published in the journal Cell Metabolism.