Race and ethnicity are terms which are often used interchangeably. To a large part, I believe it is due to the increasing political incorrectness of using race as a descriptor, thus moving the notion of race more towards that of ethnicity.A 1950 UNESCO declaration "The Race Question", succinctly puts it:
"National, religious, geographic, linguistic and cultural groups do not necessarily coincide with racial groups: and the cultural traits of such groups have no demonstrated genetic connection with racial traits. Because serious errors of this kind are habitually committed when the term 'race' is used in popular parlance, it would be better when speaking of human races to drop the term 'race' altogether and speak of 'ethnic groups'."
"National, religious, geographic, linguistic and cultural groups do not necessarily coincide with racial groups: and the cultural traits of such groups have no demonstrated genetic connection with racial traits. Because serious errors of this kind are habitually committed when the term 'race' is used in popular parlance, it would be better when speaking of human races to drop the term 'race' altogether and speak of 'ethnic groups'."
Race in its original intent referred to the "roots" of population groups (etymology: Germanic 'reiza' - bloodline). This to a large extent referred to biological characteristics and the external appearance of the population groups. The term 'race' therefore carries heavy connotations about biology and heredity.
We know now that these notions are fallacious, and believe that there are no biological bases for classification of peoples into racial groups. Race is little more than a socio-political construct that allow societies to manage resource allocations.
The UNESCO declaration was correct. The term 'race' should actually be dropped from our vocabulary altogether as it is meaningless from a biological perspective, and its continued use just continues to perpetuate the myth that people can be sub-classified according to biology.
The more correct and useful term is 'ethnicity'. Ethnicity refers to population groups that are unified by social and cultural characteristics as well as geographic origins. That different ethnic groups have differing phenotypic features do not make them definable by these characteristics.
Pharmacogenetic studies as well as studies looking at inter-populational variability in drug responses, should refer to ethnicity as a descriptor of the population rather than to race. This would then include allele frequencies, anthropometric information, environmental exposures and other societal pressures. The academic challenge presented is how do we standardize these ethnicity descriptors so that that we can understand and apply the data being generated from these studies. Correctly however, ethnicity data have limited applicability across populations. For example, data on Chinese in Singapore do not necessarily apply to Chinese populations in China, Africa, Europe or US. Likewise, we should not too readily apply Chinese data generated in Beijing to a Singapore therapeutic context.
In our lab we use the terms Chinese, Malay and Indians because these are terms used by our National Registration Office. However in our studies we recruit subjects based on self-declaration of ethnicity (Chinese, Malay and Indians) consistent over three generations. The data we generate will be correct for our population as at this time, and we make no assertions that they can be representative of Chinese, Malay and Indian populations across the globe, or even for Singapore population groups for later generations.
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dear Prof, lets say if a person self-declared to be a Chinese, but there's someone (eg. his grandmother) is an Indian. So the genetic make-up is somehow "slightly" different from other Chinese. Do we still consider him as a "reliable" subject in the pharmacogenetic drug response study? Let's assume that his social or cultural background is the same as the other Chinese.
ReplyDeleteAnother doubt is that, as what you've mentioned, the outcome from drug response test on Singaporean Chinese cannot be used in Beijing Chinese. So in this case, it is the environment/geography that causes the physiological changes in both populations, thus lead to the changes in pharmacokinetics, so we cannot use the Sg Chinese data on Beijing Chinese?
Hope my questions are clear enough... Thank you! :)
Well, it really depends on your criteria. The NRIC doesn't check on the heritage and depends on self declaration, so if in the example you cite, it may be adequate if you do not require 3 generations of similar ethnicity for "purity". If the PG study requires 3 generations then it would not be adequate.
ReplyDeleteIt's not a matter of reliability of the subject but how much stringency you want to impose on the study. One non-Chinese parent contributes 50% non-Chinese genes, and 1 non-Chinese grandparent contributes 25%. One non-Chinese great-grandparent would be expected to contribute only 12.5% and we would accept that as a relatively small 'contamination'.
Your second point is correct. One should not expect to be able to directly apply completely across populations because the ethnicity of Singapore Chinese is really different from the ethnicity of a Beijing Chinese, and in fact there are evidences of subtle differences. But if your requirements are not too stringent, you could possibly accept that they are close enough for certain extrapolations to be made.
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ReplyDeletepharmacogenetics