[Nosography of autism. Critical discussion of current classifications]

Child autism is a serious and early-forming developmental disorder and its nosography is evolving quickly. Classifications of autism have been produced since the works of Kanner in 1943 and especially in the last fifteen years, or so in order to respond to the needs of clinical practice and of research. Because of the presence of borderline or various uncommon clinical forms and, more generally, considering the heterogeneousness of clinical conditions concerning autism, it appears necessary to break up autism into better defined sub-groups. Moreover, the existing systems do not apply very well before the age of two or three, when the diagnosis and investigations nevertheless begin. Progress is achieved today by using simultaneously multidimensional and quantitative evaluations, an example of which is presented. In the future, a knowledge of etiological factors and/or the identification of biological markers will guide the classification of developmental disorders.