Caucasian population

Cystic fibrosis, a disease of the Caucasian population, is associated with defective CL regulation and is essentially a disorder of epithehal cells (113,114). The defect arises at several levels in the CL ion transporter, ie, the cystic fibrosis transmembrane regulation (CFTR), and is associated with defective CL transport and defective processing, whereby the protein is not correctiy incorporated into the cell membrane. The most common mutation, affecting approximately 60% of patients, is termed F 608 and designates the loss of phenylalanine at this position. This mutation appears to be at least 50,000 years old, which suggests that its survival may have had evolutionary significance (115). 

Pseudocholine esterase Low or absent activity in 0.05% of Caucasian populations. Prolonged action of succinylcholine and mivacurium. 

Cytochrome P450 2C9 Low activity in about 10% (heterozygotes) and very low activity in about 0.8% (homozygotes) of Caucasian populations. Prolonged action of several CYP2C9 inactivated drugs like phenytoin, tolbutamide, ibuprofen, or S-warfarin. 

Cytochrome P450 2C19 Deficient activity in about 3% of Caucasian populations and in about 20% of Asian populations. Prolonged action of several CYP2C19 inactivated drugs like omeprazole or diazepam in the poor metabolizers. 

Cytochrome P450 2D6 Extremely high activity in about 2% of Caucasian populations and completely deficient activity in about 7%. Inefficiency in ultrarapid metabolizers and extremely heavy effects in poor metabolizers for more than 50 drugs. A few drugs requiring bioactivation by CYP have low efficacy in poor metabolizers (example codein is activated to morphine via CYP2D6). 

A/-acetyltransferase 2 Low activity in about 60% of Caucasian populations. High incidence of adverse events from the drug isoniazide in slow acetylators. 

Staessen JA, Wang JG, Brand E et al (2001) Effects of three candidate genes on prevalence and incidence of hypertension in a Caucasian population. J Hypertens 19 1349-1358... 

In the United States, CF most commonly occurs in the Caucasian population, ranging from 1 in 1900 to 3700 individuals. CF is less common in Hispanics (1 in 9000), African-Americans... 

While generally not of major concern, omeprazole may inhibit the metabolism of warfarin, diazepam, and phenytoin lansoprazole may decrease theophylline concentrations. Drug interactions with omeprazole are of particular concern in patients who are considered slow metabolizers, as are approximately 3% of the Caucasian population. Unfortunately, it is unclear which patients have the polymorphic gene variation that makes them slow metabolizers.17 The metabolism of esomeprazole may also be altered in patients with this polymorphic gene variation. Patients on potentially interacting drugs should be monitored for development of drug-related problems. 

Psoriasis is a common inflammatory skin disorder which is estimated to affect 1.5% to 3% of the Caucasian population.1,2 It may present at any age.3,4 Ethnic factors influence disease prevalence. In the United States, prevalence among blacks (0.45% to 0.7%) is lower than in the remainder of the United States population (1.4% to 4.6%).1 Between 10% and 30% of patients with psoriasis will also have psoriatic arthritis.5 In 10% to 15% of psoriatic patients with arthritis, joint symptoms actually appear prior to skin involvement.3 Clinical depression is another frequent comorbid illness in these patients. A recent United States survey showed that 8% to 10% of psoriatic patients aged 18 to 54 years old actively contemplated suicide because of their psoriasis.6... 

Reference Respiratory Values for a General Caucasian Population at Different Levels of Activity ... 

For extrathoracic deposition of particles, the model uses measured airway diameters and experimental data, where deposition is related to particle size and airflow parameters, and scales deposition for women and children from adult male data. Similar to the extrathoracic region, experimental data served as the basis for lung (bronchi, bronchioles, and alveoli) aerosol transport and deposition. A theoretical model of gas transport and particle deposition was used to interpret data and to predict deposition for compartments and subpopulations other than adult males. Table 3-4 provides reference respiratory values for the general Caucasian population during various intensities of physical exertion. 

Xie, H. G., Stein, C. M. et al. (1999). Allelic, genotypic and phenotypic distributions of S-mephenytoin 4 -hydroxylase (CYP2C19) in healthy Caucasian populations of European descent throughout the world. Pharmacogenetics, 9(5), 539-49. 

Inoue, K. et al. (1997). Relationship between CYP2C9 and 2C19 genotypes and tolbutamide methyl hydroxylation and S-mephenytoin 4 -hydroxylation activities in livers of Japanese and Caucasian populations. Pharmacogenetics, 7, 103-13. 

Ng, C.H., Norman, T. R., Ho, B. et al. (2006a). A comparison study of sertraline dosages, plasma levels, efficacy and adverse reactions in Chinese versus Caucasian populations. Int. 

Tayeb, M. T. et al. (2000). CYP3A4 promoter variant in Saudi, Ghanaian and Scottish Caucasian populations. Pharmacogenetics, 10, 753-6. 

The most interesting aspect of the results of the study by Lee etal (2004) is that they also differ from those in a Caucasian population (Smeraldi, Benedetti Zanardi, 2002). The authors reported a more favorable natural history in those with the s/s genotype than in 1-allele carriers, which also differs from acute antidepressant responses in Caucasian populations. The frequencies of the s and 1 alleles among the Korean sample were approximately 86% and 14%, respectively, while the corresponding figures for Caucasians are 43% and 57% (Lesch etal, 1996). 

Nakamura, K., Goto, F., Ray, W. A. etal. (1985). Interethnic differences in genetic polymorphism of debrisoquine and mephenytoin hydroxylation between Japanese and Caucasian populations. Clin. Pharmacol. Ther., 10,402-8. 

Despite the plethora of new drug developments in neuroscience, most clinical drug trials are conducted in predominantly Caucasian populations even though they are used frequently in non-Caucasian populations. There is an urgent need to clarify the appropriateness of extrapolating research data of clinical drug trials... 

A total of 13 polymorphisms in the gene and its transcriptional regulator beta-upstream peptide (BUP) have been identified [73]. Three closely linked polymorphisms, two coding block SNPs at amino acid positions 16 and 27, and a SNP in the BUP were found to be common (i.e., allele frequency >0.15) in the general Caucasian population [74, 75]. 

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. 

The alleles containing 4 and 9 copies of the TSER repeat were primarily confined to African populations. TSER 4 accounted for 2-7% of TSER alleles in all African populations except the Sudanese. However, TSER 4 was also found in a British Caucasian subject but not among the American-Caucasian population studied [53]. This suggests that TSER 4 occurs at a low frequency in Caucasian populations. The absence of the TSER 4 allele in the Sudanese population may be a result of the small sample size or due to the fact that this allele occurs at very low frequencies in this population. The latter possibility would make sense as this population is an admixture of Negroid and Caucasoid characteristics at both the morphological and molecular levels [17]. 

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