Potential dyslexia gene identified

NEW HAVEN, Conn., Oct 28, 2005 (UPI via COMTEX) -- Yale University researchers say they've identified a gene that may be responsible for dyslexia, one of the most common neurobehavioral disorders.

Dyslexia, a reading disorder, affects up to 17 percent of the population.

Yale researchers identified an inherited component to reading disability, and some potentially responsible chromosome regions. The most widely reported region is on chromosome 6, which contains about 19 genes, most of which are expressed in the brain.

Jeffrey Gruen of Yale's Child Health Research Center and colleagues genotyped 153 families affected dyslexia and located the likely source of the susceptibility region: a deletion in the DCDC2 gene.

While that gene's function is unknown, it is similar to DCX, a gene that helps guide neuron migration in the brain. Gruen's team decreased DCDC2 gene expression in rats and observed that neurons migrated shorter distances.

DCDC2 was also found to be activated in the same brain regions in both fluent and dyslexic readers, suggesting dysfunction, and not disruption, of the gene occurs in those with reading disability. Therefore, the evidence supports the identification of DCDC2 as a dyslexia gene.

The research appears in the journal Proceedings of the National Academy of Sciences.

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