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Early Speech Difficulties
As
is the case with many toddlers, Michael Thieme's early spoken language was quirky.
He called his older
brother William "Illiam," for example. "He
couldn't get his W's out," his mother, Annette Thieme, said. Unlike
most, Michael had speech problems that persisted into kindergarten, putting him
at risk for the reading difficulty known as dyslexia. Michael's
parents didn't stop at speech therapy. They
also enrolled both sons in a five-year study at the University of Denver to uncover
why early speech and language problems so often lead to dyslexia. The
study, which just ended, showed a genetic link between early speech problems and
later dyslexia. Both
problems showed up in the same genetic regions, said DU psychologist Bruce Pennington.
He presented results
Wednesday at the International Dyslexia Association's annual meeting in Denver.
The discovery could
lead to earlier intervention for kids at risk of reading disorders, to a better
understanding of the brain structures underlying speech, language and reading,
and, eventually, to drugs that help correct problems, Pennington said. "Not
too long ago, people said complex disorders were all in your mind, or in your
experience," he said. "Now
we're finding they're like a lot of medical diseases - heart disease, diabetes.
Genes change anatomy
and affect disease." Annette
Thieme suspects it was her genes that affected her son's early speech. "I'm
sure it came from me," Thieme
said, as her sons, now 9 and 11, demonstrated the gamelike tests researchers challenged
them with during the past several years. Pulling
on headsets to listen to recorded directions, Michael and William quickly became
engrossed in a task involving remembering odd new names given to tiny plastic
animals. A giraffe
became "said," for example, William explained. In kindergarten, Annette Thieme
struggled with speech, she said, in much the same way Michael did. Both
mother and son outgrew their speech and language problems, and neither has dyslexia,
a reading disorder in which people have difficulty recognizing or deciphering
printed words. But
about one in three toddlers who have speech and language problems do develop dyslexia,
Pennington's team found. Researchers and educators want to learn how to pick out
those vulnerable children early, to get them extra help, he said. Pennington
and other researchers cautioned that there are no true "reading genes." Reading
is a cultural invention only a few thousand years old, too young for evolution
to have shaped genes to control it, said Robert Dougherty, a Stanford University
biologist. 
Instead,
reading relies on brain structures developed for other purposes, from visual to
communicative, he said. So
perhaps it's not surprising that Pennington and other scientists are finding not
one gene but many associated with speech, language and reading problems. Shelley
Smith, a geneticist at University of Nebraska Medical Center, ran tests on the
families Pennington studied. She
found that early speech problems corresponded to regions of at least three chromosomes
- 1, 6 and 15, all also involved in dyslexia. Psychologists,
geneticists and anatomists are finally unveiling the connections among genes,
brains and language that lead to strong or poor readers, she said. "This
is such an exciting time," she said. "It's finally all coming together." By
Katy Human. Original
article. With
many thanks to the highly recommended Denver
Post.
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