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Pharmacogenetics of Arylamine N-acetyltransferase genes in South African populations

Thesis (PhD)--Stellenbosch University, 2012.

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Main Author: Werely, Cedric J.
Other Authors: Van Helden, Paul J.
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2012
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access_status_str Open Access
author Werely, Cedric J.
author2 Van Helden, Paul J.
author_browse Van Helden, Paul J.
Werely, Cedric J.
author_facet Van Helden, Paul J.
Werely, Cedric J.
author_sort Werely, Cedric J.
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (PhD)--Stellenbosch University, 2012.
format Thesis
id oai:scholar.sun.ac.za:10019.1/71832
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:46:50.651Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2012
publishDateRange 2012
publishDateSort 2012
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
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source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/71832 Pharmacogenetics of Arylamine N-acetyltransferase genes in South African populations Werely, Cedric J. Van Helden, Paul J. Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences. Molecular Biology and Human Genetics. Tuberculosis (TB) -- Diagnosis -- South Africa Drug metabolising enzymes and tuberculosis Genotypic analyses Theses -- Molecular biology Dissertations -- Molecular biology Theses -- Genetics Dissertations -- Genetics Tuberculosis -- South Africa -- Prevention Biomedical Sciences Thesis (PhD)--Stellenbosch University, 2012. Includes bibliography ENGLISH ABSTRACT: Tuberculosis (TB) has been declared a global health emergency by the World Health Organisation, and consequently there is an urgency to develop improved methods of diagnosis and treatment. Despite the current TB epidemic, the disease can be treated effectively using isoniazid (INH) in combination with other antibiotics. However, INH is inactivated in the body by certain drug metabolising enzymes, which may reduce the efficacy of TB treatment. The activity of these drug metabolising enzymes, called NAT, are in turn reduced by nucleotide changes (SNPs) in the gene. These genetic variants (alleles) have been correlated with the rapid- (FA), intermediate- (IA), and slow acetylation (SA) enzymatic activity, and one is therefore able to investigate potential phenotypic effects via genotypic analyses. We investigated these genetic changes in the NAT1 and NAT2 genes in individuals from the local Coloured community (SAC) since this group has one of the highest TB incidences in the country. NAT2 is primarily responsible for the inactivation of INH, whilst NAT1 metabolises para-aminosalicyclic acid (PAS) which is used in the treatment of drug resistant TB. The NAT2 results indicated that the NAT2 alleles were not equally represented in three local ethnic groups studied, and subsequently the rapid, intermediate and slow acetylation activity reflected these differences. However, the relative frequency of these variants in the SAC and Caucasian groups were relatively low. These differences require further investigation to determine their overall relevance to the NAT2 activity differences between groups. In the case of the NAT1 analysis we also observed differences in the relative frequency of various NAT1 alleles between Caucasian and SAC individuals. However, many of these NAT1 SNPs and alleles have not as yet been characterised, so effects of these variants are currently unknown. Interestingly, the NAT1*4 and NAT1*10 alleles were the most prevalent NAT1 alleles in both Caucasians and SAC. The NAT1*4 allele exhibits the rapid NAT1 activity, whilst the activity of the NAT1*10 allele is currently subject to ongoing debate. In this respect, the analysis of NAT1 continues to be a topic for ongoing research. These results, observed for the NAT genes, underscore the importance of doing genetic analyses in local ethnic groups, since these differences may vary significantly between the groups. AFRIKAANSE OPSOMMING: Tuberkulose (TB) is deur die Wêreldgesondheidsorganisasie (WGO) tot 'n globale gesondheidsnood verklaar en derhalwe is dit noodsaaklik dat nuwe, verbeterde diagnostiese metodes ontwikkel word, wat tot meer effektiewe behandeling kan lei. Ten spyte van die huidige TB-epidemie, kan die siekte doeltreffend behandel word deur middel van isoniasied (INH), in kombinasie te met ander antibiotika. INH kan egter geïnaktiveer word deur sekere ensieme in die liggaam, met die gevolg dat INH nie meer effektief is nie in die behandeling van TB. Die aktiwiteit van hierdie ensiem, die sogenaamde NAT2 (Arielamien N-asetieltransferase 2) ensiem, word op sy beurt beïnvloed deur sekere nukleotied veranderings (SNPs) in die geen. Hierdie genetiese veranderings gekorreleer met ensiemaktiwiteitsveranderings (geklassifiseer as vinnig (FA) Intermediêr (IA) en stadig (SA)), wat mens in staat stel om potensiële fenotipiese effekte te ondersoek deur middel van genotipiese analise. Ons het hierdie genetiese veranderings ondersoek in die NAT1 en NAT2 gene in individue van die Kleurling-gemeenskap (SAC) omdat díe bevolkingsgroep die hoogste voorkoms van TB in die land het. NAT2 is primêr verantwoordelik vir die inaktivering van INH, terwyl NAT1 para-amienosalisilaat (PAS) inaktiveer, wat gebruik word in die behandeling van midel-weerstandige TB. Die NAT2 resultate dui daarop dat die allele van die NAT2 geen nie eweredig verteenwoordig wasin die drie etniese groepe nie en derhalwe word die vinnige (FA), intermediêre (IA) en stadige (SA) ensiemaktiwiteite deur hierdie verskille weerspieël. Hoewel die teenwoordigheid van hierdie variante relatief laag was in die SAC en Koukasiër gemeenskappe, is verdere studies nodig om die omvang van hierdie verskille te bepaal ten onsigte van NAT2 aktiwiteit tussen groepe. In die geval van die NAT1 analise het ons verskille waargeneem in die voorkoms van verskeie NAT1 allele tussen Koukasiese en SAC individue. Baie van hierdie NAT1 SNPs is egter nog nie gekarakteriseer nie, en derhalwe is die effek van hierdie NAT1 variante onbekend. Die NAT1*4 en NAT1*10 allele was die prominentste NAT1 alleel in beide Koukasiërs en SAC. Die NAT1*4 is betrokke by vinnige NAT1 aktiwiteit, terwyl die effek van die NAT1*10 alleel nog onderhewig is aan aktiefwe debat. In hierdie verband, is die studie van NAT1 steeds 'n onderwerp vir toekomstige navorsing. Hierdie resultate, wat vir die NAT gene waargeneem is, beklemtoon die belangrikheid van verdere genetiese analises in plaaslike etniese groepe, aangesien hierdie verskille beduidend kan wees tussen die verskillende groepe. Doctoral 2012-11-26T10:23:27Z 2012-12-12T08:13:30Z 2012-11-26T10:23:27Z 2012-12-12T08:13:30Z 2012-12 Thesis http://hdl.handle.net/10019.1/71832 en_ZA Stellenbosch University xvi, 236 p. : col. ill. application/pdf Stellenbosch : Stellenbosch University
spellingShingle Tuberculosis (TB) -- Diagnosis -- South Africa
Drug metabolising enzymes and tuberculosis
Genotypic analyses
Theses -- Molecular biology
Dissertations -- Molecular biology
Theses -- Genetics
Dissertations -- Genetics
Tuberculosis -- South Africa -- Prevention
Biomedical Sciences
Werely, Cedric J.
Pharmacogenetics of Arylamine N-acetyltransferase genes in South African populations
title Pharmacogenetics of Arylamine N-acetyltransferase genes in South African populations
title_full Pharmacogenetics of Arylamine N-acetyltransferase genes in South African populations
title_fullStr Pharmacogenetics of Arylamine N-acetyltransferase genes in South African populations
title_full_unstemmed Pharmacogenetics of Arylamine N-acetyltransferase genes in South African populations
title_short Pharmacogenetics of Arylamine N-acetyltransferase genes in South African populations
title_sort pharmacogenetics of arylamine n acetyltransferase genes in south african populations
topic Tuberculosis (TB) -- Diagnosis -- South Africa
Drug metabolising enzymes and tuberculosis
Genotypic analyses
Theses -- Molecular biology
Dissertations -- Molecular biology
Theses -- Genetics
Dissertations -- Genetics
Tuberculosis -- South Africa -- Prevention
Biomedical Sciences
url http://hdl.handle.net/10019.1/71832
work_keys_str_mv AT werelycedricj pharmacogeneticsofarylaminenacetyltransferasegenesinsouthafricanpopulations