[Clinical aspects of chromosomal aberrations - problems of semiotics and nosography]

Despite intense clinical and cytogenetic research for more than 15 years we are far from knowing any definite relations between karyotype and phenotype. Both cytogeneticists and clinicians are working on the methodological improvements which are still necessary. In the methods of clinical recording there is still very great weakness of exact documentation of findings. Above all there is a lack of reproducible qualitative, and especially quantitative standards which constitute the basis of any practicable nosography. Some procedures for quantifying dysplastic facial features which have hardly been described so far (graphic statistics) are reported briefly. Also the summation of symptoms, a method currently used in the field of chromosomopathy syndromes, is subject to critical consideration. In this group of diseases a total list of symptoms of about 250 items can be obtained which includes multilocular minor stigmata, dysplasias, errors of differentiation and gross malformations of organs. An extraordinarily high degree of overlapping of symptoms is characteristic of these syndromes and makes accurate diagnosis difficult. However, for the trisomy-syndromes we succeeded in working out a diagnostic guideline by differentiating between an unspecified basic symptomatology concerning all trisomias and a pattern-forming additional symptomatology of each single syndrome. Thereby the diverse total symptomatology is reduced to the crucial and the recognition of patterns in daily practice is facilitated considerably. The comparatively specific additional symptomatologies of trisomy 13 -- 14 (Patau), trisomy 17 -- 18 (EDWARDS), and trisomy 21 (DOWN) are demonstrated in graphic views.