Genetic Determinism

In fact, it was inevitable that genetic science was going to have to face this question sooner or later.

It would appear that in addition to hereditary diseases, chronic diseases, and mental disorders, genetic research cannot avoid focusing on infectious diseases.

Last year Marie Lin, director and professor at the Immunohematory Reference Laboratory, Mackay Memorial Hospital, conducted truly pioneering gene research on the SARS virus here in Taiwan.

In September of last year, Dr. Lin, who had for a long time focused her research on blood groups and ethnic groups, published the results of a study entitled "Correlation between SARS virus infection and the human leukocyte antigen." Lin concluded that there is a direct connection between the presence of the human leukocyte antigen HLA-B46 and the severity of a SARS infection. She found that ethnic southern Chinese who

have the HLA-B46 antigen are relatively susceptible to SARS infection. Among the Fukienese and Hakka ethnic groups, 11.4% of the population are carriers of this gene, a higher percentage than in other ethnic groups.

When Lin published her findings, which received considerable attention abroad and have been cited some 40 to 50 times, her research was widely thought to be moving in the right direction. But when she proposed screening doctors and nurses to determine who belonged to a low-risk group and could be sent to care for SARS patients, her suggestion was not acted on.

Chang Shan-chwen, director of the Division of Infectious Diseases at National Taiwan University Hospital, thinks that the presence of HLA-B46 is not a necessary condition for a SARS infection to occur. People without this antigen can still get SARS, though their infection rate is lower.

Chen Yuan-tsung, director of the Institute of Biomedical Sciences, Academia Sinica, thinks that the predictive value of Lin's approach is not high, because saying that someone is "relatively unlikely to contract SARS" is not the same as saying they "will not contract it." Dr. Chen says that only a rate of incidence at least ten times above normal has predictive value for clinical screening.

Because the number of samples used in Lin's study was small, because the results of her estimates could not be verified, and because there were ethical misgivings concerning ethnic bias, the Department of Health turned down her offer to use 10,000 doses of a screening reagent manufactured by Mackay Memorial Hospital to test doctors and nurses who were treating SARS patients. Lin was frustrated and bewildered by this decision, because all she had wanted to do was to help reduce the dangers to which medical personnel were exposed.

Dr. Lin says, "I'm no expert in epidemiology. I stumbled into this line of research more or less by accident, but went about it full of enthusiasm." As for the accusations that she was guilty of ethnic bias, Lin considers them to be beyond the pale.

In fact, this incident illustrates a bizarre thing about genetic screening. Genes not only contain humanity's life code, but they also make it possible to trace the origin and development of an individual's ancestry as far back as a hundred generations. Remember the movie The Human Stain, about a fair-skinned professor of black ancestry who pretends to be Jewish throughout his life? Sadly, no matter what we pretend to be or how we change ourselves, we cannot wipe away our genetic imprint.

It remains to be seen whether humanity's hereditary code will be cracked, but the dark clouds of genetic determinism are already on the horizon. Society ought to investigate and debate how to avoid unequal treatment, discrimination, and segregation based on ethnicity or genetic background.