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

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

"minor defects of the organism may be passed on dormantly to the offspring through generations, until one of them meets one of the opposite sex with a similar defect or disposition, then the so far latent structural defect comes to light. So the origin of the disease should not be searched for in the acquired affections of the immediate ancestors." When being elected corresponding member of the Hungarian Academy of Sciences in May 6, 1898, he gave account of his work in genetics in his discourse entitled "Data to heredity and hereditary diseases". He analysed 25 cases of 14 families. In 1902 he published this lecture in six parts in the Orvosi Hetilap as "Third communication" in a somewhat modified form: "Data to the knowledge of hereditary diseases". And this is the most absorbed summarization of the doctrine of heredodegeneration in the Hungarian language. His statement is still acceptable: "...we search the solution of the cases in the influence of the aetiology upon the organism." "In the group

... of hereditary degenerations the aetiology should be looked for in the individual defects of the parents. The human organism has arrived to such a high evolutionary level that no one can be said to be perfect." It means that we must count in everybody with some unfavourable hereditary faculties the predominance of which depends upon the choice of mating of the parents. Coming to the conception of heredodegeneration, he writes: "While some years ago Friedreich's ataxia, familial spastic paralysis, Huntington's chorea, etc. were described as subtypes of tabes, spastic spinal paralysis, chorea

..., nowadays we must regard hereditary diseases as akin to each other." He mentions as an analogy tuberculosis: ".. .rather illuminating is the circumstance that nowadays we consider lupus as well as skin, pulmonary and bone tuberculoses one and the same disease since their aetiology is the same, why not to link then e. g. spastic spinal paralysis and Friedreich's ataxia ? Many will answer that because symptomatically the two clinical pictures differ very mucnl But are lupus and pulmonary tuberculosis not different from each other? On the other hand "...one can hardly collect all types of the group of dystrophies so precisely separated some years ago," since "the great diversity of types and the unlimited transition of the types into each other make all outlined classification go to ruin." In his opinion "... heredity as aetiology .. .is an endogenic cause that derives its origin from the inherited reduced viability of the respective factors of the organism; these defective factors meet in infinite combinations, thus hereditary diseases are homogeneous only in the same family, otherwise they vary without transition within the most extreme bounds." Here he puts forward his 7 points which have formed since then the basis of the doctrine of heredodegeneration. 1. "Simptoms of undoubtedly and at least in the general outlines identical clinical pictures that occur in the same family do not develop in the same degree, perhaps neither in the same extent in the case of individual members. The general character of the clinical picture is faithfully preserved in most of the cases, but details slightly vary". (The different expressivity of the hereditary diseases has been proved many times since then.) He also pointed out that "cases of the respective families show different clinical pictures from that of other families, but among themselves always attack in almost the same form, the difference corresponds to the initial or the advanced stage of the disease". (The increased intrafamilial similarity refers to the background effect of the familial genes in common.)