Clue Found for Genetic Contributor to Language Impairment
Ed at Not Exactly Rocket Science has given a good description of a new study revealing a link existing between SLI (Specific Language Impairment), Autism and a gene called CNTNAP2. The short version of the story is this: higher prevalence of a certain type of CNTNAP2 = higher prevalence of SLI and autism. Of course, as with any new research, cautions abound regarding the true nature of the cause and effect relationship as well as the need for more research. Additionally interesting is that CNTNAP2 seems to be controlled by the notorious FOXP2 gene (A.K.A. language gene). Although FOXP2 was originally hyped as a language gene several years ago because of its high correlation to language deficits, subsequent research has shown that it is present in other species and may be more of a “learning gene,” or “sequencing complex movements” gene. As far as CNTNAP2 is concerned, despite it’s implication in language disorders, the presence of this connection seems to be much rarer than the disorders themselves. This fits in well with my prediction that when the research dust settles, we will find that disorders like SLI and autism (much like stuttering has been found to be) involve complex interactions between genetic, behavioral, psychological, and environmental factors. And, the amount of each of these contrasting, overlapping ingredients will be found to be highly variable from individual to individual. In my own professional experience as a person who assesses child language, the contribution of persisting phonological production deficits in SLI has been seriously overlooked.