[A practical diagnostic approach to mental deficiency in 2002].

The identification of an etiology in children with mental deficiency is a major challenge in routine pediatrics. As the result of a workshop leaded by the Société française de neurologie pédiatrique (SFNP), we propose a three steps diagnostic procedure, taking into account several frequent clinical observations leading to further targeted investigations. The yield of systematic imaging and biological screening remains very low, when performed for a non specific isolated mental retardation, without any characteristic clinical features. Yet, it is mandatory for an accurate genetic counseling to know not only the clinical diagnosis of developmental delay, but also the pathophysiology and the underlying molecular mechanism. The SFNP's proposal points out the necessity of a comprehensive clinical process including cautious neurodevelopmental assessment, reliable cognitive and adaptive skills evaluation, and collaboration between different specialists.