"Any break in his routine or any interruption gave him so much anxiety," said Sherry Mergner Hrynewych, Noah's mother.
Something good may come from such struggles. Recently Duke Center for Human Genetics scientists identified a stretch of DNA that could contain important autism-related genes. They did it after focusing research on families coping with the type of behaviors that grip Noah.

The research approach merges new genetic science with clinical knowledge acquired over generations. And it could help scientists better track genes involved in many complex illnesses, such as heart disease, Alzheimer's disease, even diabetes.

"We need to maximize the clinical data we've collected. Maybe then we can crack the complex disorders we are trying to get a handle on," said Margaret Pericak-Vance, director of the genetics center.

In the case of autism, which probably has genetic roots, doctors and therapists have long observed that people with the developmental disorder have trouble communicating and otherwise interacting. They also can display unusual behaviors. One is the resistance to change that experts call "insistence on sameness."

In the back yard of their Chatham County home, Noah Hrynewych takes off his shoes and socks as his 2-year-old brother, Nathan, and father, Bohdan, look on. Noah's parents volunteer for genetic studies.

In the Duke study, the researchers used statistical tools to organize people with different types of behaviors into subgroups, including those who resist change. When they looked closely at a stretch of DNA on chromosome 15 in that group's blood samples, they found missing pieces and other distinctions. That chromosome long has been suspected as important in developmental ailments.

In time, researchers hope to zero in on significant genes on the chromosome. If they do, they may be able to provide information useful for developing new medicines or therapies to compensate for what goes awry among the autistic on the molecular level.

"It's not all about science. We would hope there may be implications for treatment down the line," said Michael Cuccaro, a clinical psychologist working at the center who diagnoses and treats children with autism.

Noah's parents, Sherry and Bohdan Hrynewych, volunteer for genetic studies such as the one at Duke for just that reason, though they don't always know when their DNA is used. But the northern Chatham County residents don't hang all their hopes on distant lab findings.

They do everything they can to nurture their dark-haired, 4-year-old boy as well as they can now. In addition to the physical therapy and the rest of what his doctors recommend, the Hrynewyches reach into nontraditional treatments too. Noah sees an acupuncturist. He eats a special diet, void of wheat or milk.

His parents adapt to the boy's aversion to change by creating rituals that help him move from task to task. In the bathroom, on the dining room table, near his car seat are laminated cards encouraging him to wash his hands, eat his breakfast or climb into his dad's car. Each time he does what is asked, he gets to deposit a card into a nearby envelope.

The Hrynewyches are certain they are helping their son, who has grown more serene. And they hope scientists working at Duke and other ambitious research campuses will some day offer guidance on how to help some more. But they don't expect any big breakthrough tomorrow.

"It's going to take a long time," Bohdan Hrynewych said, "for all those strands to come together."

Staff writer Catherine Clabby can be reached at 945-2414 or at cclabby@newsobserver.com.