Ped Med: The many faces of autism
SAN FRANCISCO, Dec. 19 (UPI) -- Although all show some degree of difficulty in socializing, communicating and imagining, like snowflakes, no two cases of autism are exactly alike, researchers say.
Their newfound recognition of the condition's diverse complexity and multi-faceted nature carries over to the research field, where the seekers of causes and cures are starting to look for ways to subdivide the disorder and crack its armor of secrecy piece by piece.
"The analogy that I find most helpful is to childhood leukemia," said Dr. Judith Miles, professor of pediatrics, Thompson Endowed Chair of Child Health and Pathology and director of the Medical Genetics Division at the University of Missouri-Columbia.
"When I went to medical school, we thought it was one disorder, and only 5 percent of kids survived. Over the past 25 years, we realized it's a class of disorders. By separating the different types and learning how to treat each appropriately, we were able to make progress so that the survival rate is now 90 percent."
Miles is convinced all that looks like autism doesn't have the same cause and, therefore, will require a different therapeutic approach.
"If we can be more precise, we can do a lot of things," she said. "That would include the ability to prognosticate a child's future capabilities and design more specific and hence more efficacious treatments."
To that end, she has proposed the criteria for identifying autism, which currently are broadly based on social, communication and behavioral symptoms, be broken down into two further categories.
The recommendation is based on her finding that 20 percent of autistic children differ from the rest in both unusual physical features, such as an abnormal head size or malformed ear or hand, and autistic symptoms, which may include lower IQ, seizures or lack of speech after age 8. The researchers dubbed this subtype "complex autism."
They noted the much larger set of youngsters without the corporeal differences tended to be male and have siblings with a high risk for autism and other kin with the disorder. They called this subdivision "essential autism."
"It's very important for families to realize that autism is not a single disorder," Miles said, noting the two subgroups she has identified have different outcomes and recurrence rates.
"Separating essential autism from complex autism should be the first diagnostic step for children with autism spectrum disorders as it allows better prognostication and counseling."
Miles's five-year investigation sets the stage for exposing autism's genetic underpinnings, she said.
"By determining if there are differences between the children who have distinct physical markers such as a small head and those who don't, we can start to identify differences in their genes," Miles said.
"Once you start splitting the disorder into subgroups, you start seeing specific trends and the water is not as muddy as it once was."
For example, Ohio State University investigators observed genetic changes found in certain cancers -- including of the breast, thyroid, uterus, endometrium and brain -- also appear in some types of autism.
They detected a mutated version of the so-called "PTEN" protein in three of 18 individuals with larger-than-normal heads and autism-spectrum disorders, including the severely impairing classic autism and Rett syndrome, a type that affects primarily girls.
Although it was based on a small study, the observation raises the possibility some people with autism and large heads may face an increased cancer risk, the authors said."