MADISON, Wis. -- A medical breakthrough by Madison researchers might permanently change the diagnosis and care of patients with Alzheimer's disease.

Two new studies show convincing evidence that the devastating, progressive neurological disorder could be detected as many as 20 years before the first symptoms show, WISC-TV reported.

"By the time you diagnose Alzheimer's disease, it's really, really late," said Bruce Hermann, co-director of the Wisconsin Center for Alzheimer’s Prevention, or WRAP, which manages the study group. "It's a devastating disorder to the family, the extended family, and it's a very costly disorder."

Dr. Mark Sager, a professor of Medicine at the University of Wisconsin School of Medicine and Public Health, and Sterling Johnson an associate professor in the school and a researcher at the Geriatric Research Education and Clinical Center at the Madison VA Hospital, presented their findings this morning at an international conference on the disease being held in Honolulu.

The discovery revolves around a gene known as TOMM40 -- identified by Duke University researchers last year -- and another gene referred to as APOE, which has long been used in detecting Alzheimer's risk.

"In this study population, TOMM40 genotyping allowed us to find evidence of very early Alzheimer's disease at least 20 years before any outward symptoms would be noticed," Sager said in a news release from the UW School of Medicine and Public Health.

"That's where the entire field of Alzheimer's disease is going, trying to detect this disease earlier and earlier, while the brain is still functional. If we want to intervene, by the time a person has dementia, the brain may have lost too many neurons already and that's when treatment is less effective or ineffective," said Johnson.

The work included more than 700 healthy, middle-aged people -- all with a family history of Alzheimer's disease. As it turns out, all carried the newly-identified TOMM40 gene, researchers said.

Researchers said they found 229 people with the high-risk version of that gene did "significantly worse" on various cognitive tests than those in the study identified as having the low-risk version of the gene.

As a result of brain imaging, researchers concluded those with the high-risk version of the gene had a less gray matter in two brain regions tied to the early onset of Alzheimer's.

The two discoveries together could give medical providers a way to eventually detect Alzheimer's early simply by doing an MRI or blood test.

Alzheimer's is the most common form of dementia in aging adults and is widely considered to be the next big public health crisis in the United States as the baby boom population continues to age. Currently, five million U.S. adults suffer from Alzheimer's, resulting in costs that mount into the hundreds of billions. By 2050 costs for caring for Alzheimer's in the U.S. is expected to exceed $20 trillion, according to a report from the Alzheimer's Association.

The association projects nationwide cases will more than double by mid-century, with cases in Wisconsin alone expected to increase by 24 percent just 15 years from now.

The WRAP study group is made up of more than 1,400 volunteers, largely from inside the state of Wisconsin. According to Hermann, about 1,100 have a family history of Alzheimer's, making it the largest single group of asymptomatic, healthy, adult children of Alzheimer's patients anywhere.

Many, like Larry Mastalish who is 72, agreed to take part after watching a loved one's decline.

"My dad had a pretty good sense of humor, so that kind of fell away as his memory declined," Mastalish said. "It's difficult when you know what their past had been, what their background had been, what they were good at, and no longer could function."

Mastalish is one of many who make trips from across the state to come to UW Health facilities, where the research is conducted. On his third visit in six years Wednesday, Mastalish underwent a vitals check, blood draw and several rounds of cognitive testing. On Thursday, he'll have a PET scan before returning to his home in Green Bay.

"If this disease is related to genetics, I certainly would want to do whatever I can for my children and grandchildren," he said. "I think part of the reason for doing it is just to try to assist, help people in the future avoid this dreadful disease."

"These people are dedicated to helping us find early indications of the disorder and how it progresses over time," Hermann said.

The findings will now be reviewed by doctors at other institutions, and could one day forever change the way Alzheimer's is treated. Early detection could lead to lifestyle changes for those with advanced risk, and help increase and enhance cognitive therapy and prevention techniques some believe can stave off the disease's progression, WISC-TV reported.