Polymorphic genes

Group of transmembrane proteins engaged in the presentation of small peptide fragments to T-cells. Two classes of Major histocompatibility complex (MHC) molecules exist both of which are encoded by a highly polymorphic gene cluster. MHC class I and class II proteins present peptide fragments to CD8+ and CD4+ T-cells, respectively. The human MHC is also known as HLA, the murine MHC as H-2 complex. 

There are only very few genes which do not carry any polymorphisms. And there exists even a significant number of polymorphic genes that are not expressed at all in part of the population due to genetic polymorphisms. Table 1 summarizes a few selected polymorphisms with their functional and medical impact. 

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. 

The seminal work by early transplant researchers eventually led to the concept of histocompatibility.1,2 Histocompatibility describes the process where polymorphic genes encode cell membrane antigens that serve as targets for immune response, even within a species. Further research in transplant immunobiology has led to an accurate understanding of the immune response after transplantation.1,2... 

N9. Nishi, S Stoffel, M., Xiang, K Shows, T. B Bell, G. I., and Takeda, J Human pancreatic beta-cell glucokinase cDNA sequence and localization of the polymorphic gene to chromosome 7, band p 13. Diabetologia 35,743-747 (1992). 

Roychoudhury, A.K., and M. Nei, Human Polymorphic Genes World Wide Distribution, Oxford University Press, New York, pp. 3-18 (1988). 

The distribution of ACE genotypes in the Spanish population was as follows ACE-I/I 14.8% in controls and 20.5% in AD ACE-I/D 45.6% in controls and 46.0% in AD and ACE-D/D 39.6% in controls and 33.5% in AD (623). In this study, a small increase in the frequency of ACE- allele was observed in LOAD (623). Nevertheless, as with many other polymorphic genes, some authors did not find association between the ACE-I/D polymorphism and AD in different populations (80,617,624-631). However, a meta-analysis of 12 case-control series published up to the year 2000 suggested that ACi genotypes are associated with AD (611), and that the ACE-D allele is more frequent in Spanish, American, and Russian AD patients than in controls (614,615,617) but not in the Italian and Jewish populations (627,632). 

Masi, T. et al. 2005. Nitrosamine 4-(methylnitrosamino) -1 - (3-pyridyl) -1-butanone-induced pulmonary adenocarcinomas in Syrian golden hamsters contain beta-2-adrenergic receptor single-nucleotide polymorphisms. Genes Chromosomes Cancer, 44 (2), 212-217. 

Strassburg CP, Kneip S, Topp J, et al. Polymorphic gene regulation and interindividual variation of UDP-glucuronosyltransferase activity in human small intestine. J Biol Chem 2000 275(46) 36164-36171. 

Blairy S, et al. 5-HT2a receptor polymorphism gene in bipolar disorder and harm avoidance personality trait. Am J Med Genet 2000 96(3) 360-364. 

U8. Utermann, G., Pruin, N., and Steinmetz, A., Polymorphism of apolipoprotein E. III. Effect of a single polymorphic gene locus on plasma lipid levels in man. Clin. Genet. 15, 63-72 (1979). 

With the use of polymerase chain reaction and restriction fragmentation length polymorphism gene-splicing technologies, anal-... 

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