Dr. Thomas D. Bird, a professor of neurology at the University of Washington School of Medicine in Seattle has found that 42 percent of offspring whose parents both had Alzheimer's went on to develop the disease themselves by age 70.
The study, appearing in March's Archives of Neurology also found that the risk grew with age. Alzheimer's typically started at about age 66 in children with two affected parents. Among offspring older than 60, more than 30 percent were affected. In those older than 70, nearly 42 percent had the disease. Previous studies have shown that the disease is common among 6 to 13 percent of the U.S. population older than 65.
The researchers collected data on the grown children in 111 families where both parents had Alzheimer's disease. The study found that there were 98 children who had gotten to age 70, and of that group 41 had developed Alzheimer's disease making it to 42 percent.
"There probably is an increased risk of Alzheimer's disease in the children of spouses that both have the disease," lead researcher Dr. Bird told WebMD. "The exact magnitude of the risk, we don't know yet."
Alzheimer's, is the most common cause of dementia, afflicting 24 million people worldwide.
