[Developmental dysphasia].

Developmental dysphasia is characterized by severe, specific and unexplained developmental language impairment. Phonologic and syntactic disorders of expressive language and perceptual deficit are almost always present. Moreover, certain specific linguistic symptoms are particular to each dysphasic child, explaining the efforts to classify different forms of dysphasia. The most important point is to separate receptive dysphasia from the expressive on the one hand, and severe forms from the mild which are closed to "simple language delay", on the other. The evolution of oral language is variable, but often long and difficult, with persistent linguistic deficit. Reading and writing acquisition is usually difficult, although very important for the socio-professional outcome and language improvement. The etiology remains unknown and is probably multifactorial. One pathogenic hypothesis is based on the absence of the usual hemisphere specialisation related to various prenatal or postnatal events. A genetic basis seems likely for certain dysphasic children. Development of knowledge about this condition and improvement of both speech therapy and teaching are essential for the outcome of these otherwise intelligent and normal children.