Pythagoras; Genetics, and Worker's Rights

THE NEW YORK TIMES, T} BOSTON — Pythagoras, best known for a theorem about the square of the hypotenuse, was also the founder of a widespread religion, Pythagoreanism, that included a rule against eating beans. This rule has long puzzled philos but we oph now have ers a rational explanation, and it happens to impinge on a current controversy. Some individuals of Mediterranean origin are poisoned by eating fava beans because these individuals have @ genetic defect in a particular enzyme that is known as G6PD. This de fect makes red blood cells susceptible to destruction by a component of the fava bean. On the other hand, it also makes these cells resistant to the malarial parasite. Accordingly, the prevalence of the defect in populations from the eastern Mediterranean can be explained by Darwinian selection — that is, when the altered gene arose by a rare mutation thousands of years ago in a malarial region, it rapidly became more frequent in subsequent generations because it allowed perm sons to survive malaria better and hence to have more progeny. The distribution of G6PD deficiency has now become a matter of broader interest, with the finding that this enzyme protects lava bean but not only also against against the many potentially toxic chemicais. Tests for this enr vine might therefore be used to detect individuals who would be at exCeptionally high risk if exposed te these compounds. Accordingly, some major chemical firms have recently begun to carry out such tests. It is not ciear how much testing of this kind is being done, nor is it clear whether the Present purpose is primarily to guide employment or to evaluate such methods for the future. In July, the Institute of Medicine of the National Academy of Sciences held a conference that included this subject within the broader topic of gene-environment interactions. The participants generally agreed that Screening for enzyme defects is still a matter for research, and not for industrial practice. However, other critics have ob jected to the screening in principle, claiming that it shifts the blame for toxic reactions from the employer to the worker, deprives people of the Pythagoras, Genetics, And Workers’ Rights By Bernard D. Davis Stances. These objections should be scrutinized carefully, lest we forecl a potentially valuable activity. ose First, the essential issue is not one of industrial conflict but is one of preventive medicine — a pragmatic field that deals with both the individual and the environment in any way that can decrease illness. From this perspective, screening for genetic differences in susceptibility to chemicals is a logical extension of the public-health practice - of Skin-testing for the presence or absence of acquired immunity to an infectious disease Second, it is artifical to quéstion screening in terms of an abstract right of equal access to a job. One could

JURSDAY, AUGUST 14, 1980 © ‘hardly defend the right of a hemophilSac to be employed as a butcher. The ¿problem is becoming more subtle ‚today: We are learning to detect pre- ‘dispositions that are not so obvious to ‘the bearer. Moreover, the problem is ‘bound to grow. The growing fusion of -genetics with immunology may soon - make it possible to identify hereditary individual differences in the likelihood ‚of developing various allergies. With — such advances, certain ilinesses cease being unpredictable acts of God. As “they become increasingly predictable "they also become more preventable — ‘by minimizing exposure, and eventually, we hope, by learning how to modify an individual's reactions. Accordingly, we cannot escape the responsibility for incorporating knowiedge of individual genetic differences . in preventive medicine. | A third claim is that the limits of exposure to any chemical in industry ought to be set low enough so that no‘body could be harmed. The moral „principle assumed here is politically | attractive. However, with our modern «knowledge of genetics it cannot be taken literally. It can hardly be economically feasible to set standards on the basis of the responses of a person far outside the norma! range of susceptibility. | Recent examples of mismanagement of toxic wastes hardly generate trust in the control of toxic exposure of workers in industry. Nevertheless, our suspicion should not blind us to the possibility that genetic screening could benefit both workers and man- Beyond the religious ban on fava beans agement. There are real questions of policy in determining who should be responsible for the screening and how i the results should be used, but an answer that would altogether reject the information would surely be unfair to the susceptible worker. If we are to proceed rationally we must try to reconcile the ideal of unlimited equality with the reality of genetic diversity. We must therefore evaluate with particular care any arguments that may be used to discourage the useful recognition of that diversity As the total suppressio of genetics n in the Soviet Union for 25 years by Trofim Lysenko reminds us, this field is particularly vulnerable to ideological assault. Bernard D. Davis is director of the of the Center for Human Genetics at the Harvard Medical School.