Browsing by Author "Nel, Etienne"

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    Exome sequencing identifies a novel TTC37 mutation in the first reported case of Trichohepatoenteric syndrome (THE-S) in South Africa
    (BioMed Central, 2017-03-14) Kinnear, Craig; Glanzmann, Brigitte; Banda, Eric; Schlechter, Nikola; Durrheim, Glenda; Neethling, Annika; Nel, Etienne; Schoeman, Mardelle; Johnson, Glynis; Van Helden, Paul D.; Hoal, Eileen G; Esser, Monika; Urban, Michael; Moller, Marlo
    Background Trichohepatoenteric syndrome (THE-S) or phenotypic diarrhoea of infancy is a rare autosomal recessive disorder characterised by severe infantile diarrhoea, facial dysmorphism, immunodeficiency and woolly hair. It was first described in 1982 in two infants with intractable diarrhoea, liver cirrhosis and abnormal hair structure on microscopy. We report on two siblings from a consanguineous family of Somali descent who, despite extensive clinical investigation, remained undiagnosed until their demise. The index patient died of fulminant cytomegalovirus pneumonitis at 3 months of age. Methods Whole exome sequencing (WES) was performed on a premortem DNA sample from the index case. Variants in a homozygous recessive state or compound heterozygous state were prioritized as potential candidate variants using TAPER™. Sanger sequencing was done to genotype the parents, unaffected sibling and a deceased sibling for the variant of interest. Results Exome sequencing identified a novel homozygous mutation (c.4507C > T, rs200067423) in TTC37 which was confirmed by Sanger sequencing in the index case. The identification of this mutation led to the diagnosis of THE-S in the proband and the same homozygous variant was confirmed in a male sibling who died 4 years earlier with severe chronic diarrhoea of infancy. The unaffected parents and sister were heterozygous for the identified variant. Conclusions WES permitted definitive genetic diagnosis despite an atypical presentation in the index case and suggests that severe infection, likely secondary to immunodeficiency, may be a presenting feature. In addition definitive molecular diagnosis allows for genetic counseling and future prenatal diagnosis, and demonstrates the value of WES for post-mortem diagnosis of disorders with a non-specific clinical presentation in which a Mendelian cause is suspected.
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    Hepatitis B virus infection in HIV-exposed infants in the Western Cape, South Africa
    (Elsevier, 2015-07) Chotun, Nafiisah; Nel, Etienne; Cotton, Mark F.; Preiser, Wolfgang; Andersson, Monique I.; Pathology: Medical Virology
    Hepatitis B virus infection (HBV) is a significant public health problem in sub-Saharan Africa. Universal infant vaccination with the hepatitis B (HB) vaccine has been implemented within the South African Expanded Programme of Immunization since April 1995 with concomitant reduction in HBV infection in children. However, the first vaccine dose is only administered at six weeks of age. This delay may lead to a failure to reduce the risk of perinatal HBV transmission to infants born to HIV/HBV co-infected women, in whom HBV infection is often upregulated. The aim of this study was to determine the prevalence of HBV infection in babies born to HIV-infected mothers in the Western Cape, South Africa. HBV serological markers were tested in all infant serum samples and following HB viral load testing, sequencing and genotyping were also performed. Three of 1000 samples screened tested positive for HBsAg and HBV DNA. An additional infant tested positive for HBV DNA alone. All babies had received the HB vaccine at 6, 10 and 14 weeks. The prevalence of HBV infection was therefore 4/1000 (0.4%; 95% CI, 0.01–0.79%). Three of four infants and all four mothers were followed-up. Two infants were persistently positive for HBsAg with viral loads above 108 International Units per millilitre. All four maternal samples were positive for HBsAg and HBeAg and one was also positive for anti-HBe. Sequencing analysis of two mother–child HBV pairs showed 100% sequence identity. This study demonstrates HBV infection in HIV-exposed infants despite HB vaccination from 6 weeks of age. A more strategic approach is needed to prevent mother to child transmission of HBV, including screening of pregnant women, HBV-targeted antiviral therapy and HB birth dose vaccine.
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    Die invloed wat agtergrondmusiek in advertensies en tipe en vlak van betrokkenheid uitoefen op verbruikers se houding teenoor advertensie, houding teenoor handelsmerk en koopintensie
    (Stellenbosch : Stellenbosch University, 1991-04) Nel, Etienne; Du Toit, J. B.; Stellenbosch University. Economic and Management Sciences. Dept. of Industrial Psychology.
    ENGLISH ABSTRACT: This study examines the effect of involvement and background music in television commercials on consumers' attitudes toward the commercial, their attitude toward the brand and their intension to buy that spesific brand. Involvement refers to type of involvement (cognitive vs affective) and the level of involvement (high vs low). The planning of the experiment had been done according to research projects in the past. A commercial with different soundtracks was viewed by different subjects. Thereafter they completed a questionniare. The members of the different groups were subjected to different manipulations. The results indicated that background music in commercials have a significant influence on consumers' attitudes towards the commercial. (cognitive vs affective) had a on consumers' attitudes towards the a significant relationship between commercial , attitude toward the brand Type of involvement significant influence brand. There was attitude toward the and intension to buy.
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    Viral hepatitis B and C in HIV-exposed South African infants
    (BMC (part of Springer Nature), 2020) Tchuem, Cynthia Tamandjou; Cotton, Mark Fredric; Nel, Etienne; Tedder, Richard; Preiser, Wolfgang; Violari, Avy; Bobat, Raziya; Hovind, Laura; Aaron, Lisa; Montepiedra, Grace; Mitchell, Charles; Andersson, Monique Ingrid
    Background: Whilst much attention is given to eliminating HIV mother-to-child transmission (MTCT), little has been done to ensure the same for hepatitis B virus (HBV) transmission. The introduction of HBV immunization at six weeks of age has reduced HBV horizontal transmission in South Africa. However, in order to eliminate HBV MTCT, further interventions are needed. The risk of hepatitis C virus (HCV) MTCT in HIV-infected (HIV+) African women is not yet well described. This study aimed to determine the rate of HBV and HCV vertical transmission in HIV-exposed infants in South Africa. Methods: Serum samples from infants enrolled in an isoniazid prevention study (P1041) were screened for HBV and HCV serology markers; screening was performed on samples collected at approximately 60 weeks of age of the infants. HBV DNA was quantified in HBsAg positive samples and HBV strains characterized through gene sequencing. All HCV antibody samples with inconclusive results underwent molecular testing. Results: Three of 821 infants were positive for both HBsAg and HBV DNA. All HBV strains belonged to HBV subgenotype A1. The rtM204I mutation associated with lamivudine resistance was identified in one infant, a second infant harboured the double A1762T/G1764A BCP mutation. Phylogenetic analysis showed clustering between mother and infant viral genomic sequences. Twenty-one of 821 HIV-exposed infants tested had inconclusive HCV antibody results, none were HCV PCR positive. Conclusions: This study suggests that HBV vertical transmission is likely to be occurring in HIV-exposed infants in South Africa.. A more robust strategy of HBV prevention, including birth dose vaccination, is required to eradicate HBV MTCT. HCV infection was not detected.