Genetic basis for dyslexia and language impairment?

http://www.sciencedaily.com/releases/2013/06/130613124318.htm

Dyslexia and language impairment are common learning disabilities that make reading and verbal language skills difficult. Both disorders have a substantial genetic component, but despite years of study, determining the root cause had been difficult.

In previous studies, Gruen and his team found that dopamine-related genes ANKK1 and DRD2 are involved in language processing. In further non-genetic studies, they found that prenatal exposure to nicotine has a strong negative affect on both reading and language processing. They had also previously found that a gene called DCDC2 was linked to dyslexia.

analyzed data from more than 10,000 children born in 1991-1992 who were part of the Avon Longitudinal Study of Parents and Children (ALSPAC)… They found that some variants of a gene regulator called READ1 (regulatory element associated with dyslexia1) within the DCDC2 gene are associated with problems in reading performance while other variants are strongly associated with problems in verbal language performance… these variants interact with a second dyslexia risk gene called KIAA0319. "When you have risk variants in both READ1 and KIAA0319, it can have a multiplier effect on measures of reading, language, and IQ," he said. "People who have these variants have a substantially increased likelihood of developing dyslexia or language impairment."

We now hope to be able to offer a pre-symptomatic diagnostic panel, so we can identify children at risk before they get into trouble at school. Almost three-quarters of these children will be reading at grade level if they get early intervention, and we know that intervention can have a positive lasting effect."