[Mental retardation and sexual development in chromosomal syndrome (author's transl)].

Mental retardation and natural sexual development appear to be a more consistent feature in the autosomal rather than in the sex chromosome anomalies. On the contrary the anatomical and functional sexual disfunction characterize the sex chromosome syndromes. An early diagnosis and a better knowledge of the chromosomal abnormalities are important for the social integration and the control of the sexual development and behaviour of this patients.