Letten Foundation Research House

Harare, Zimbabwe

Letten Foundation Research House

Harare, Zimbabwe
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Mhandire K.,University of Cape Town | Mhandire K.,University of Zimbabwe | Mhandire K.,Letten Foundation Research House | Duri K.,University of Zimbabwe | And 6 more authors.
South African Medical Journal | Year: 2016

Background. Apolipoprotein B mRNA-editing catalytic polypeptide like-3G (APOBEC3G) is an antiviral enzyme that reduces viral fitness by introducing uracil to thymidine hypermutations in viral genomes. Thus, polymorphisms in the APOBEC3G gene have been implicated in differential outcomes of HIV infection and disease progression. However, there is insufficient evidence on the role of APOBEC3G gene variants on HIV infection, especially in African populations. This study therefore describes polymorphisms in the APOBEC3G gene in a Zimbabwean paediatric population and evaluates their effects on susceptibility to HIV infection among children born to HIV-infected mothers. Methods. A total of 104 children aged between 7 and 9 years, comprising 68 perinatally exposed to HIV (32 born infected (EI) and 36 born uninfected (EU)) and 36 unexposed and uninfected (UEUI) controls were recruited. Allelic variants (n=5) in the APOBEC3G gene were characterised. Results. Frequencies for minor APOBEC3G alleles in the HIV-uninfected groups (EU and UEUI) were c.557G (40%), g.-90C (32%), g.-571C (12%), c.467-85C (42%), and c.582-162G (6%). APOBEC3G c.467-85C frequency was statistically significantly different when compared to the Masai of Kinyawa, Kenya population (42% v. 18%). None of the single nucleotide polymorphisms individually or as part of haplotypes were significantly associated with HIV infection when comparing the EI and EU groups. Conclusions. Our findings suggest that APOBEC3G polymorphisms alone may not have significant predictive power for inferring genetic susceptibility to vertical transmission of HIV in children perinatally exposed to HIV. © 2016, South African Medical Association. All Rights Reserved.


Mhandire K.,University of Cape Town | Mhandire K.,Letten Foundation Research House | Mhandire K.,University of Zimbabwe | Duri K.,University of Zimbabwe | And 7 more authors.
Journal of Infection in Developing Countries | Year: 2014

Introduction: There is growing evidence that polymorphisms in chemokine and chemokine receptor genes influence susceptibility to HIV infection and disease progression. However, not much is documented about the prevalence and effects of chemokine and chemokine receptor gene variations in the Zimbabwean population despite the high burden of HIV/AIDS in the country. This study therefore describes polymorphisms in CCR2, CX3CR1, SDF1 and RANTES genes in a Zimbabwean pediatric population and their effects on HIV infection in children born to HIV-infected mothers.Methodology: A total of 106 children between seven and nine years of age comprising 70 perinatally exposed to HIV (34 born infected [EI] and 36 born uninfected [EU]) and 36 unexposed and uninfected (UEUI) controls were recruited. Six allelic variants in four genes were genotyped using PCR-RFLP and sequencing.Results: Frequencies for minor alleles in the HIV uninfected groups (EU and UEUI) were CCR2 190A (16%), SDF1 801A (2%), CX3CR1 745A (9%), CX3CR1 839T (0%), RANTES In 1.1C (20%), and RANTES -403A (44%). There were significant differences between the EI and EU groups in the distribution of CCR2 190G/A genotype (15% versus 39%, respectively, p = 0.02) and CCR2 190G/A-CX3CR1 745G/G genotype combination (0% versus 33%, respectively, p = 0.002).Conclusions: Our findings suggest that chemokine and chemokine receptor gene variants seem to play an important role in the dynamics of HIV infection and could be used as drug or vaccine targets. © 2014 Mhandire et al.


Mhandire K.,University of Cape Town | Mhandire K.,Letten Foundation Research House | Pharo G.,University of Cape Town | Kandawasvika G.Q.,University of Zimbabwe | And 7 more authors.
OMICS A Journal of Integrative Biology | Year: 2014

Mannose binding lectin (MBL) is a pathogen pattern recognition protein involved in antimicrobial activities. Variation in MBL2 gene has been extensively implicated in differential outcomes of infectious diseases in studies conducted outside Africa, but virtually very little is known on the role of this candidate gene in the African continent. We investigated human genetic variations in MBL2 in a Zimbabwean pediatric population and their putative associations with HIV infection in perinatally exposed children. One hundred and four children aged 7 to 9 years comprising 68 perinatally exposed to HIV (32 who were born infected and 36 who were uninfected) and 36 unexposed controls were recruited. DNA samples were genotyped for MBL2 polymorphisms using PCR-RFLP and sequencing. HIV infected children had markedly variable and significantly lower mean height (p=0.03) and weight (p=0.005) when compared to the uninfected children. Using all samples, frequencies for MBL2 genetic variants for the Zimbabwean population were calculated. Twelve single nucleotide polymorphisms were observed and minor alleles occurred with the following frequencies: -550C>G (G: 0.02), -435G>A (A: 0.08), -428A>C (C: 0.39), -394A>G (A: 0.39), -328AGAGAA ins/del (AGAGAA ins: 0.44), -245G>A (A: 0.05), -221C>G (C: 0.12), -111A>T (T: 0.10), -70C>T (C: 0.46), +4C>T (C: 0.45), novel -595G>A (A: 0.02), and 170G>A (0.24). We found that the MBL2 +4T variant displayed a trend for association with reduced risk of HIV transmission from mother-to-child but the remaining vast majority of the genetic markers did not show a significant association. We conclude (1) the MBL2 gene is highly polymorphic in the Zimbabwean population, and (2) MBL2 genetic variation does not appear to play a major role in influencing the risk of mother-to-child HIV transmission in our study sample. These observations contest the hitherto significant role of this candidate gene for HIV transmission from mother-to-child in non-African populations and thus, further speak to the limits of extrapolating genomic association studies directly to the African populations from studies conducted elsewhere. It is hoped that more OMICS research in a diverse set of African countries can shed further light on the putative role (or the lack thereof) of this candidate gene in HIV transmission in the continent, a major global health burden in Africa. © Copyright 2014, Mary Ann Liebert, Inc. 2014.

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