Professeur Jérôme Lejeune

Préface de l'Atlas of Chromosomal Syndromes de Tatsuo ABE, et Hiroko Fujita, 31 Mars1981, Japon.


A Japanese atlas of chromosome abnormalities has been in a great need. Few years ago an excellent book written in French and its English edition were published by Jean dc Grouchy and Catherine Turleau under the name: Atlas des maladies chromosomique. This atlas has been and will remain very useful but all the descriptions and the illustrations concern children of European ancestry. Hence it is very appropriate that professors Abe and Fujita started a comprehensive atlas in which Japanese patients could be presented and compared.

Cytogenetics is a morphological science, at least to start with. Under the microscope the picture of a chromosome is identical for all mankind. The pathology is also universal and a trisomy, a deletion or a translocation looks just the same the world over. But when it comes to the features of the affected children, the racial origin is of clinical relevance. If one remembers how long it took to eradicate from the cytogenetic vocabulary the wrong name of "mongolism", unfortunately applied to trisomy 21, one has a good example of a misunderstanding due to incomplete knowledge of normal and abnormal morphology. Indeed, in order to study the epicanthus in a trisomic 21 child one must know the normal shape of the eyelids in the very kin to which the patient belongs.

Here the atlas of chromosome abnormalities will render great services. It will fill a real gap in the medical science of morphology related to chromosomal afflications. By establishing pathognomonic standards, it will allow better clinical diagnosis, earlier referral to specialists and, thanks to its excellent technical part, permit more precise cytogenetic investigations.

But beyond this remarkable achievement, this atlas will also serve a more general goal, by rendering more obviously the unity of the whole human family.

For example, a careful analysis of the illustrations featuring cases of trisomy 21 or of Cri du chat syndrome immediately reveals that each disease modifies the shape of the body or the outlook of the face in exactly the same way in every child, whether he is born in Paris or in Kyoto.

Under this "general mask of the disease" one recognizes the personal, familial, and ethnic characteristics of each patient. Through this comparison, the old sentence that all human beings are brothers becomes more than a philosophical proposition; an experimental evidence.

This leads to the sense of common responsibility of all the scientists in view of helping the disabled children. Thanks to the successful enterprise of Professors Abe and Fujita, cytogenetists will efficiently join their endeavour toward a better understanding of the chromosomal diseases and of their deleterious effects.

Actually, against chromosomal errors no effective treatment has been offered. No reasoned therapy has yet been invented to bring back to normalcy the intellectual power so dramatically affected by most of these diseases. At first glance this atlas could seem as a collection of chromosomal misfortunes against which medicine is entirely powerless. No remedy being available, discarding of the abnormal babies, if early diagnosed in utero, has even be considered as a substitute for prevention.

But despair has never been the way to progress in medicine. To the reader, who may be too affected in his sensibility by these malformations, it seems necessary to remember that this atlas is indeed a milestone. But a milestone is not the end of the road; it is as well a starting point of new roads yet to be explored.

It would be out of place to discuss here the eventuality of true prevention, i.e.: the discovery of the actual causes of chromosomal errors and of protective measures against them. Although such a chapter will be hopefully written some day, I would simply focus on very localized point.

The fragile-X syndrome has been recently individualized among the cases of sex-linked mental retardation. Affected boys (girls also are known) suffer from a severe deficiency of intelligence, and their X chromosome, in lymphocyte cultures, exhibits a gap at the zone Xq27 or Xq28. This weak point often breaks.

After the discovery by Sutherland (1) that addition of folic acid to the culture medium could repair this fragility, the mechanism of the disease has been investigated in depth.

We already know that the mental disorder and the chromosomal fragility are related to an inborn error of the one-carbon cycle metabolism (2). Even the clinical condition as well as the chromosomal instability can be greatly improved if the children receive an appropriate medication increasing the turnover of their metabolism (3).

These very recent developments certainly need confirmation and further research, but they show us, for the first time, that a better knowledge of cytogenetics will some day give to medicine the power of helping efficatiously the disabled children.

Having personally witnessed the first stammerings of human cytogenetics nearly a quarter of a century ago, I do appreciate the book by Professors Abe and Fujita as an important monument of our science. It will surely give a new impetus to research and will foster better cooperation of all the scientists in the world toward our common goal: the betterment of the condition of the disinherited children who have not received an equitable chromosomal patrimony.



(1) Sutherland 1979 - Amer.J. Hum. Genet., 31, 125-135.

(2) Lejeune 1980 - C.R. Acad. Sci. 290, serie D, p. 1075.

(3) Lejeune 1981 - C.R. Acad. Sci. 292, serie III, p. 491.