pp. 422-423 in Bioethics in Asia

Editors: Norio Fujiki and Darryl R. J. Macer, Ph.D.
Eubios Ethics Institute

Copyright 2000, Eubios Ethics Institute All commercial rights reserved. This publication may be reproduced for limited educational or academic use, however please enquire with the author.

F21. Japan Society of Human Genetics, present and future.

Yasuo Nakagome.

Juntendo University School of Medicine; President, Japan Society of Human Genetics

It is my privilege and pleasure to introduce the Japan Society of Human Genetics to the Fukui Satellite Symposium of UNESCO Asian Bioethics Conference. The Japan Society of Human Genetics (JSHG) was founded in 1956. This was the year when chromosome number of normal humans was found to be 46 and not 47 nor 48. Although ABO blood group had been known since 1900, the Rh blood group was discovered in 1941. The defective enzyme in phenyl ketonuria was identified in 1952. These examples illustrate the background of the start of JSHG.

Shortly after this year, a number of important discoveries in the field of human genetics followed. Examples included, identification of amino acid substitution in hemoglobin S disease in 1957, detection of 21 trisomy in Down syndrome in 1959 and proposal of Lyon hypothesis in 1961. It was in 1968 when the first autosome locus was successfully mapped to a specific chromosome.

In the 1950s, human geneticists were concerned with pedigree analysis, study of effects of consanguinity or elucidation of characteristics of isolated populations. In 1960, I decided to choose human genetics for my dissertation work. In fact, all of my fellow physicians were surprised and asked me why? At that time, available research tools were too limited to do almost anything and human genetics appeared to be at the extreme fringe of medicine to most, if not all, physicians. Earlier developments were summarized in a recent review by Yanase (1).

Through the 60s and the 70s, studies on chromosome abnormalities, enzyme defects and abnormal hemoglobin prevailed. In the early 80s, the age of DNA started. I remember the 1982 annual meeting of JSHG when I myself presented results of DNA analysis first time. There was only one additional report which also used DNA techniques. In October 1997, we had the 42nd Annual Meeting in Kobe. May be around 80% or so of presented papers used DNA techniques.

Let me show a few examples of genes cloned by the members of JSHG, xeroderma pigmentosum type A, acetoacetyl-CoA thiolase, tooth enamel defect of X-linked type (amelogenin), the causative gene of familial polyposis of colon, DRPLA (dentatorubral and pallidoluysian atrophy), congenital insensitivity to pain with anhidrosis, congenital muscular dystrophy of Fukuyama type and ABO blood group gene. These represent examples of contributions in research by JSHG members.

Study of possible genetic differences among various ethnic groups is another field of importance. A genome diversity project has started to cope with the problem. There are various diseases each of which is very common in an ethnic group but rare in other groups. Cystic fibrosis is common among Caucasians, but rarely found in Asians or Negroes. Tay Sachs disease in Ashkenazi Jews, adrenogenital syndrome in Eskimos, lactose intolerance in Asians are among other examples of diseases common in some of the ethnic groups.

It is also known that in the natives of both Central and South America, both A and B allele of ABO blood group are lacking. In other words, practically all natives of these area have blood group O. During the last glacial period, which ended about 14,000 years ago, both Siberia and Alaska was connected and formed a huge continent. Their ancestors originated from southeast part of Siberia and walked across Behring strait to Alaska. However, huge glaciers covering entire Canada hindered further procession. When the glacial age approached to its end, land connecting Siberia and Alaska was drowned in the ocean, shortly before the disconnection, a small pass opened up between the glaciers. A very small number of people, most of whom had blood group O, successfully entered the area which roughly correspond to the main land of US. They are ancesters of all the natives of Central and South America. This represents the effect of migration and isolation to the genetic constitution of an ethnic group.

There are other mechanisms which might cause changes of genetic constitution of some ethnic groups. The most famous example would be malaria and increase of the Hb S gene. The mechanism is called selection. These examples were presented to demonstrate that many ethnic groups of developing countries are likely to have peculiar genetic constitution. Then what is the implication of the peculiarity? At the moment, major health problems in developing countries are related to either infections or undernutrition. However, as soon as the infection is controlled, genetic problems are likely to emerge because of the genetic peculiarities mentioned above. We must be prepared for it.

In developed countries, the use of DNA analysis has spread to almost every aspect of medicine. Over 3 thousand genetic defects can now be diagnosed using DNA technique. The importance of DNA diagnosis will further increase in the near future, as increasing number of rather common diseases have been found to be caused by multifactorial inheritance, in addition to known single gene defects that are rather rare. Examples included a variety of congenital abnormalities, diabetes, hypertension, allergy and hypercholesterolemia. DNA diagnosis will pick up individuals who are at risk in any of these diseases. Then parents can try to accustom the child to, for example, low cholesterol diet, in case the child is found to be at risk to hypercholesterolemia. It is expected that newborn screening programs will start in the near future which will detect millions of people who are not patients but are known to have defects in some of the genes and thus at risk for diseases. It was proposed that to name these people "unpatients".

To cope with the increase of unpatients, it was proposed (not decided yet) in the US that human genetics should be compulsory in the examinations for the medical license. In any event, the need for human genetic education in both medical schools and in the postgraduate education must be emphasized. Unfortunately, human genetic education is grossly lacking in most of colleges of nursing and health sciences in Japan. We have just dispatched a questionnaire to all schools of these kind to grasp the situation in individual schools. We are also preparing to propose a minimum level of human genetic knowledge which graduates of these schools should have.

In addition to the science and education, it is also our responsibility to propose guidelines on ethical issues related to genetic and/or prenatal diagnoses. Dr. Matsuda, who is the chairman of the ethics committee of JSHG, discussed it this morning and English version of guidelines were published in a recent issue of Jpn. J. Hum. Genet. ( 2 and 3).

The widespread use of DNA diagnosis and the start of possible newborn screening programs will drastically increase the need of genetic counseling. It is, as I see it, a crime to do DNA diagnosis or screening without genetic counseling. We need a nation-wide system of counseling and a training program to increase both number and quality of genetic counselors. Also coverage of genetic counseling by the nation-wide health insurance system is needed. We already submitted a petition on it November 1996.

We will keep pursuing all of these goals.

References

1. Yanase, T. Human genetics, past, present, and future, with special reference to major trends in Japan. Jpn. J. Hum. Genet. 42: 265-316, 1997.

2. The Japan Society of Human Genetics: Guidelines for genetic counseling and prenatal diagnosis. Jpn. J. Hum. Genet. 42: 375-377, 1997. [See also EJAIB 6 (1996).]

3. The Japan Society of Human Genetics: Guidelines for genetic testing using DNA analysis. Jpn. J. Hum. Genet. 42: 377-379, 1997. [See also EJAIB 6 (1996).]


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