HEBER - When their 3-year-old twin sons started stumbling and losing their speech, Leo and Linda Witt hoped it wasn't serious.

When the seizures began, and blood tests and brain scans came back inconclusive, the Witts hoped for answers. And when - after two years of testing - doctors reached a diagnosis of Batten Disease, a rare and fatal neurological disorder, the Witts hoped for a miracle.

Earlier this month, Logan and Tyrel Witt succumbed to respiratory failure and died just nine hours apart. They were 9 years old.

Knowing an adult stem cell treatment for Batten Disease is being investigated in Oregon, Linda Witt struggles with a terrible sense that her sons "were born at the wrong time." But she remains optimistic for other families pinning their hopes on treatments from such cells.

Adult stem cells are less versatile than embryonic stem cells - but also less controversial, easier to come by and may be marketed for new therapeutic uses in the U.S. much sooner.

In Utah, researchers are exploring whether adult stem cells can help repair damaged hearts or restore nerves' ability to communicate.

Hope for broken hearts. Doctors already use adult stem cells in treatments in the U.S. - bone marrow transplants, for example - and are inching closer to innovative new uses.

Adult stem cells are more developed than embryonic stem cells, which are extracted from days-old embryos. Adult stem cells can be gleaned from bone marrow, umbilical cord blood, aborted fetuses and tissues throughout the body.

Studies suggest they retain some ability to transform. Such cells from bone marrow, for example, can become skeletal or cardiac muscle cells. That means they could be injected into hearts to repair tissues damaged by a heart attack or heart disease.

G. Russell Reiss, a cardiothorasic surgeon at the Veterans Affairs Medical Center in Salt Lake City, has federal approval to try injecting bone marrow stem cells into the hearts of patients with coronary artery disease.

Preliminary studies have shown the cells can improve heart function after heart attacks, he said. While doctors once believed stem cells turned into heart cells, replacing damaged ones, it now appears that they play more of a support role, excreting chemicals near the injury and assisting in repair.

"Stem cells' best natural purpose is in reducing inflammation and enhancing tissue repair," said Reiss, who hopes to start enrolling patients this summer.

More Utah innovators. Michael Pulsipher, director of the Utah Blood and Marrow Transplant Program, is conducting several clinical trials to find safer ways to transplant blood and bone marrow into adults and children.

The hope is that patients who receive donated bone marrow transplants after chemotherapy would have fewer immune reactions, said Pulsipher, an assistant professor of hematology and pediatrics at the University of Utah.

And Q Therapeutics in Salt Lake City is using technology licensed from the U. to discover whether adult stem cells can restore myelin - the coating on nerves that enables them to conduct impulses between the brain and other parts of the body.

Once Q Therapeutics is able to show "proof of concept" with adult stem cells, it will begin exploring embryonic stem cells' potential, said president and CEO Deborah Eppstein.

The company expects its cell therapy for spinal cord injuries to be in clinical development at Johns Hopkins University by mid-2008 - and on the market within five to seven years.

Linda Kelley, director of the Cell Therapy Facility at the U., helps companies like Q Therapeutics move from laboratory experiments to trials with patients.

The U.'s 8,000-square-foot lab, the only one of its kind in the Intermountain West, has scientists and students with the skills and interest to get clinical trials approved and off the ground faster, she said.

"I think the biggest bottleneck is from basic scientific discovery to a basic clinical trial," she said.

Beating Batten? In Oregon, researchers are using adult stem cells to treat children with Batten Disease, hoping to slow or reverse its effects.

Working with scientists at Palo Alto, Calif.-based StemCells Inc., Oregon Health Sciences University doctors began a Phase I clinical trial last year. Neural stem cells, according to the company's Web site, were isolated from the brain of a fetus, then purified, expanded and frozen.

The cells were then transplanted into the brains of children with Batten disease by pediatric surgeons. The Witts had hoped to enroll Logan and Tyrel, but were told the boys had become too ill.

The fraternal twins were healthy and inseparable as toddlers. Logan was more cerebral and Tyrel a "real go-getter," said their father. "We called them search and destroy."

But midway into their third year, the boys seemed to plateau, then began to stumble and fall. Then came seizures, long hospital stays, a battery of tests and the diagnosis.

"At first we thought we had the world by the tail, because if we knew what was wrong, we could fix it," said Leo Witt. "But when a doctor tells you to take your kids home and love them as much as you can, that's quite a hard hit in the head."

"Life became so hard." The Witts scoured the Internet for promising therapies and raised money for research. Meanwhile, they worked to provide their sons "the best life possible."

The boys attended school and church. They went on family vacations to Disney World and "loved to go to the city park and listen to music," said Leo.

As their disease progressed, the twins lost their sight and their ability to walk, talk and feed themselves. Toward the end, they relied on machines to breathe.

"They were aware of favorite people, favorite sounds and of being loved up until the last month," said Leo.

Around-the-clock care took its toll on the Witts, as did financial and political roadblocks to their quest for a cure.

Because Batten Disease is so rare, there is little incentive for pharmaceutical companies to develop treatments. As for politicians quick to condemn stem cell research as immoral, Leo suggests "they go to someone's home where a child is dying slowly, having the mucus and blood sucked from his lungs and sinuses."

Still, the Witts don't dwell on "what ifs." They call their sons the "Witt Warriors" and say they brought out the best in everyone who knew them.

"As a mother, you really want longevity for your kids. But life became so hard for them. They really stayed as long as they could, maybe even longer for my sake," said Linda Witt, who takes comfort in her faith and "knowing we'll see them on the other side."

The boys' classmates said it best, she said, referring to a school billboard that read: "Farewell, Logan and Tyrel. Thank you for being our teachers."

Q&A

What are adult stem cells, where do they come from and how do they differ from embryonic stem cells? B4.

What are adult stem cells?

* Q. Do adult stem cells come from adults?

* A. "Adult" refers to the development of the cell, not its source. Adult stem cells can be gleaned from umbilical cord blood, aborted fetuses, bone marrow and tissues throughout the body.

* Q. For researchers, what's the major difference between embryonic and adult stem cells?

* A. Embryonic stem cells can become any cell in the body. Adult stem cells are less flexible. For example: Certain adult stem cells from blood or bone marrow can become three major types of brain cells, skeletal muscle cells, cardiac muscle cells or liver cells.