Clues to dyslexia

A genetic test may be around the corner.

Dyslexia is treatable, especially if it’s caught early—but testing children for the neurological disorder is complex and expensive, and we miss many cases. What we need is a genetic screening test, says Jeffrey R. Gruen, professor of pediatrics, genetics, and investigative medicine. That test may be around the corner, thanks to his recent discoveries.

Gruen’s team probed a gene associated with dyslexia, finding within it an intriguing piece of cellular machinery. READ1, as they dubbed it, is highly variable; every child inherits two of its 40 alleles, or variants. Trawling the DNA of more than 10,000 British children, the team found that one of those alleles appeared to be bad news; it was three times likelier to show up in kids with a severe dyslexia-like disability than in normal kids. Still, it didn’t go far enough toward predicting dyslexia risk to be, in itself, a good genetic screening tool.

Then the researchers compared all children in the database who have the flawed READ1 allele with children who have a flawed allele from another dyslexia gene. Those who inherit either allele do subtly worse than other kids on language and reading tests. But kids unlucky enough to have inherited both alleles do up to eight times worse, suggesting that the genes interact synergistically to enable or disable reading. Eventually, these findings could help lead to earlier diagnosis of children at high risk—so that early intervention programs can ensure them greater success in school.

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