Ethnicity defined

If ethnicity is determined to be a factor, how is ethnicity defined and determined [14]... 

Essential to the definition of Pharmacogenetics is the term genetic polymorphism. It is extrapolated that there are at least three million genetic polymorphisms in the human genome. Historically, a genetic polymorphism was defined as a genetic variation with a population frequency of 1% and above, but the larger inter-ethnic variation of population frequencies makes a strict definition based on such frequencies impractical. The most common molecular type of polymorphism is the... 

Before going on to analyze the importance of taking cultural factors into account in order to correctly identify symptoms and, therefore, to reach a correct diagnosis and apply a suitable treatment, we are going to briefly review some of the terms frequently used to talk about cultural factors, such as race or ethnicity, as well as acculturation. Despite their widespread use both by laypersons and in academic spheres, these terms have rarefy been defined and on occasions are even used indistinctly (Adebimpe, 1994). 

As is apparent from the literature reviewed above, that culture and ethnicity are powerful determinants of an individual s response to psychopharmacotherapy. Progress in this regard will vastly improve our current practice in using medications. However, it is necessary to remember that there are often very substantial inter-individual variations within any defined cultural or ethnic group, and that ethnic variations in pharmacological responses should not be interpreted stereotypically. 

The TPMT 2 allele (G238C) accounted for 9.4, 7.1 and 5.5% of the mutant alleles in the British, French and American populations, respectively. However, this allele was not found in any of the Ghanaian subjects and was not detected in the other African or Asian subjects. These findings are consistent with those of a recent study, which found that the TPMT 2 allele was present in British Caucasians and not in Chinese or Southwest Asian subjects [52]. In addition, the TPMTk2 allele was not detected in Kenyan subjects [54]. This suggests that TPMTk2 is either very rare in non-Caucasian populations or specific to Caucasians, or both. The recently identified TPMT mutant alleles TPMT 4- 8 appear to be relatively rare in Caucasian subjects. Their contribution to variant alleles in other ethnic groups has yet to be defined. 

Deficiency of thiopurine S-methyl transferase (TPMT) is another phenotype that exhibits inter-ethnic differences in frequency. TPMT is an enzyme that catalyzes methylation of therapeutic agents used in the treatment of acute lymphoblastic leukemia, rheumatoid arthritis, and autoimmune/inflammatory diseases, as well as in organ transplantation. Patients who have TPMT deficiency experience less efficient methylation and are at greater risk of fatal toxicity when treated with standard doses of fhiopurines. TPMT phenotype is defined by erythrocyte 6-mercapto-purine methylation. African American populations exhibit a 20% lower erythrocyte TPMT than Caucasian Americans, and persons of Chinese descent tend to exhibit greater activity than either of these other American subpopulations. 

To avoid the stigma and discrimination that may result from misinformation, one must avoid the casual use of race or ethnicity in research and design. Where ethnicity is relevant to a particular area of research, care must be taken to define and justify the use of race and ethnicity for the purpose of that research. As general public knowledge of the role of the gene in biology and in the practice of medicine increases, the definitions of race and ethnicity are likely to evolve to suit the proper, rather than the superficial, use of such concepts in social discourse. 

What are the ethical, legal, social, and scientific implications of pharmacogenomics Given the current disparities and the role—however illegitimate—of skin color and ethnicity in the distribution of medical services, how might new approaches to therapy affect socially defined groups of African, Asian, and Hispanic descent These questions are complex individually, and they become more so when intersected. 

The terms race, ethnicity, and minority are also used in this chapter. Race refers to a group that is socially defined on the basis of physical characteristics. Ethnicity refers to a shared culture and lifestyle, especially as reflected in language, folkways, religious and other institutional forms, material culture such as clothing and food, and cultural products such as music, literature, and art. Finally, the term minority group refers to a part of a population differing from others in some characteristics, which often subject them to differential treatment (Byrd and Clayton, 2002 Van de Berghe, 1967). 

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