Antall József szerk.: Orvostörténeti közlemények 87-88. (Budapest, 1979)

TANULMÁNYOK - Czeizel, Endre: A heredodegeneraciós tan történeti értékelése (angol nyelven)

of which those affected by TSD "remain quite exempt". Thus histopathologically and genetically Schaffer considered the two clinical pictures different. The third difference lies in the clinical picture. On this basis, too, Schaffer differentiated TSD from Niemann-Pick disease. The final answer was given after the determination of the chemical nature of stored lipoids. In 1939 Klenk demonstrated phospholipidsphyngomyelin in Nieman-Pick disease, and later different ganglioside in TSD. (This latter was identified by Svennerholm in 1962 as glandioside GM2.) Thus re-examinations confirmed the nosologic indépendance of TSD and Niemann-Pick disease. Schaffer was one of the initiators of the trend now on its peak that aims at "splitting" pathogenetically different, clinically similar diseases. It is for the sake of prevention, e. g. the fundamental difference in genetic counseling. Comparing TSD with the histopathology of other heredodegenerative clinical pictures, he set up general rules, too. By this he wanted to lay the developmental anatomic foundations for heredodegenerative clinical pictures which he already considered to be of different genetic origin, but which could be included into a uniform category on the basis of their general pathologic characteristics. As he wrote: "anatomically, heredodegeneration is characterized not by a morphologically more or less outlined deformity of the neural elements, but by a much more general momentum that is given in the theory of evolution." He made a distinction between the factors of morphologic, taxonomic, and histologic evolution. Within this he distinguished pathomorphologic (hypogenesis) and pathohistologic (dysgenesis: degenerative) trends. The exact definition of the so-called electivity triad is the following: 1. Germ layer electivity (or cotyledon choice). Generally, e.g. in TSD, neurons of ectodermic origin fall ill while meninxes, interstitial cells and vessels of mesodermic origin remain intact. 2. Segment electivity (or evolutional choice). Even within the ectoderm, neurons belonging to certain definite foetal segments tend to fall ill. Mainly the philogenetically younger parts take part in the heredodegenerative process. 3. System electivity. Even within the definite evolutionary segments deriving from a definite germ layer, generally only one or a few systems get affected. TSD meant an exception since in that case all the neurons were damaged. Although his electivity triad provoked a useful debate promoting development, it was not accepted in a broader international circle. This group of illness is rather mentioned in the literature after Spatz as systematic atrophy. The other root of Schaffer's interest in human genetics can be looked for in the pathogenesis of frequent psychoses. He tried to approach the considerable genetic specificity of these clinical pictures from morphology. In his opinion, "the concept of constitution can be explained only by the rules of heredity". According to his definiton: "constitution means the totality of healthy and pathologic hereditary traits of the mind and body of the individual." Constitution includes a predisposition for certain diseases. He points out that constitution and predisposition respectively may manifest themselves in most cases only when environmental triggering factors are present. He traced back the incidence of frequent psychiatric diseases to the joint resultant of hereditary predisposition and external provocation. With this he became a precursor of the nowadays most plausible multifactorial threshold model.