[The chromosomal syndromes (author's transl)].

Considering the results of modern cytogenetics in the area of chromosomal abberation, we can adopt without restriction two demands formulated by G. Koch (1971). First, further systematic research on mentally subnormal children should be carried out to clarify whether forms of chromosomal-genetic abnormality based on previously unknown structural alterations in one or several chromosomes can be discovered among those labelled "mentally subnormal". Second, the chromosomal-genetic forms of mental subnormality should be differentiated psychologically in close cooperation with child and adolescent psychologists and psychiatrists.