May 05, 2015

Child Prodigies and Autism: Is There a Genetic Link?

Child prodigies may share certain genetic traits with people who have autism, new research suggests.

The finding could help explain why the two groups share certain characteristics, such as exceptionally good memories. But the small number of child prodigies studied makes the findings preliminary, other scientists said.

In the study, researchers looked at DNA from 12 children with extraordinary abilities in music, mathematics or other fields. They also looked at 39 other people who were all members of the children's families, including 10 family members who had autism, and four prodigies who also had autism.

The researchers found there were genetic markers on chromosome 1 that were shared between the prodigies and their relatives with autism, the study authors said, though they have yet to find the specific mutations involved.

For the study, the researchers defined a prodigy as a child who achieved national or international recognition for a specific skill by adolescence. For example, one prodigy had played an entire DVD of classical music by ear at age 3, and earned a spot on a symphony by age 6, said study co-author Joanne Ruthsatz, an assistant professor of psychology at The Ohio State University.

Prodigies clearly share traits with children who have autism, such as exceptional memories and attention to detail, Ruthsatz told Live Science.

David Henry Feldman, chair of the Eliot-Pearson Department of Child Study and Human Development at Tufts University, agreed, telling Live Science in an email, "On the behavioral side, there seems to be a correlation between prodigies and autistic children that is hard to ignore."

However, a weakness of the study is its small number of participants — there were 12 prodigies, and four to 14 family members per prodigy in the study, Dr. Daniel Geschwind, director of the Center for Autism Research and Treatment at UCLA, who was not involved in the study, told Live Science in an email. [Beyond Vaccines: 5 Things that Might Really Cause Autism]

"The study is very small — not statistically convincing," Geschwind said. "The authors say the results are suggestive, so they are not making strong claims. But still, I am not sure there is anything really here."

The researchers would like to include more participants in future studies, but the rarity of child prodigies makes that difficult, Ruthsatz said. Over the past 100 years, the scientific literature has recorded fewer than 20 prodigies. Autism spectrum disorder, in contrast, affects an estimated 1 in 68 children, according to the Centers for Disease Control and Prevention.

The study's value comes primarily in raising new questions, Raphael Bernier, a University of Washington researcher and clinical director of the Autism Center at Seattle Children's Hospital, told Live Science.

"I think it's a great preliminary project," said Bernier, who was not involved in the study. "It starts asking the question about the relationship between prodigies and autism."

The finding, if confirmed, could also support one theory of autism: that the disorder results from long-distance-connectivity deficiencies in the brain, Bernier said.

In addition to seeking more subjects, Ruthsatz said she and colleagues are working with collaborators at McGill University in Montreal to sequence the specific mutations that may be involved. She also noted that, in the study, researchers looked at only the "100 most popular mutation sites," but in future work, the researchers will expand their search for shared regions to the entire genome.

Ruthsatz said she hopes further work will illuminate why the shared genetic variations benefit prodigies but cause dysfunction in autism. "We're now looking for the moderator that's shutting down the genes responsible for dysfunction in autism," she said. Finding such a gene could lead to new autism treatments, Ruthsatz said.

The study was published online March 10 in the journal Human Heredity.

(Source: livescience.com)

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