Introduction: The continual increase of type 2 diabetes (T2D) prevalence is a global
public health concern. The aetiology of T2D has not been fully elucidated and this is
hampering the development of effective preventative and curative interventions to curb
the T2D burden. Although much has been done to elucidate the environmental risk
factors associated with T2D, little is known about the precise genetic risk factors that
predispose people to it. There is limited knowledge about the common variants
associated with T2D risk in the black South African population. However, evidence of
shared common variants associated with T2D among people of different ethnicities has
been documented. Nonetheless, the majority of the common variants that have been
reported to be associated with T2D in other ethnicities are still yet to be evaluated in the
black South African population.
Objectives: The aim of this study was to evaluate the association of previously
reported common genetic variants with T2D susceptibility, as indicated by impaired
glucose tolerance (IGT), in a black South African population of Tswana descent.
Methods: This study was a case-control study of 180 cases and 180 controls nested in
the Prospective Urban Rural Epidemiology (PURE) study baseline data, which was
collected in 2005. The DNA samples of the participants were genotyped for 77 single
nucleotide polymorphisms (SNPs), using Illumina® VeraCode technology on the
BeadXpress® platform. The gPlink software was used to evaluate the standard genetic
models of disease penetrance for the association of the common variants with impaired
glucose tolerance (IGT) while adjusting for age, sex and body mass index.
Results: Four out of the 66 SNPs that were evaluated through the genetic association
tests in this study were noted to be significantly associated with IGT (p< 0.05). Of the
four SNPs, only rs1436955 was associated with an increase in T2D risk, while the other
three variants, rs831571, rs8050136 and rs7542900, were noted to be associated with a
decreased risk of T2D. However, none of the four SNPs was significantly associated
with IGT after correcting for multiple testing (p <0.05).
Conclusions: Black South Africans of Tswana descent might not share common
variants associated with T2D risk, as indicated by IGT in other ethnicities. Wellpowered
studies are required to evaluate the association of common variants with T2D
risk in this population group. The results from this study emphasise the need for population-specific variants to assess the genetic susceptibility of complex diseases
such as T2D in the black South African population. / MSc (Nutrition), North-West University, Potchefstroom Campus, 2014
| Identifer | oai:union.ndltd.org:NWUBOLOKA1/oai:dspace.nwu.ac.za:10394/13236 |
| Date | January 2014 |
| Creators | Chikowore, Tinashe |
| Source Sets | North-West University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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