What causes specific language impairment in children

OnlineOpen: This article is available free online at www.blackwell-synergy.com ABSTRACT—Specific language impairment (SLI) is diag-nosed when a child’s language development is deficient for no obvious reason. For many years, there was a tendency to assume that SLI was caused by factors such as poor parenting, subtle brain damage around the time of birth, or transient hearing loss. Subsequently it became clear that these factors were far less important than genes in deter-mining risk for SLI. A quest to find ‘‘the gene for SLI’ ’ was undertaken, but it soon became apparent that no single cause could account for all cases. Furthermore, although fascinating cases of SLI caused by a single mutation have been discovered, in most children the disorder has a more complex basis, with several genetic and environmental risk factors interacting. The clearest evidence for genetic ef