Immunohistochemical determination of mismatch repair gene product in colorectal carcinomas in a young indigenous African cohort.

BACKGROUND: Colorectal cancer (CRC) in the indigenous African population of South Africa is uncommon (age standardised incidence rates of 11.29 for males and 7.27/100 000 for females) and tends to occur at a young age. Lynch syndrome (LS), an inherited mismatch repair (MMR) gene abnormality, accounts for 3-4% of newly diagnosed CRCs in high incidence areas. There is some evidence that the contribution of an MMR abnormality to the overall CRC burden may be increased in low incidence areas. We aimed to determine the prevalence of MMR deficiency in an indigenous African population. METHODS: A cohort of 66 self-declared indigenous African patients, less than 50 years of age at diagnosis with CRC was identified from clinical and pathological records. The original histopathology was reviewed to confirm the diagnosis and features suggestive of MMR abnormality determined (pushing edge, mucinous, lymphocytic infiltration, Crohn's like reaction). Where sufficient tissue was available, samples were sectioned and stained for the four MMR proteins. RESULTS: Histopathological examination confirmed adenocarcinoma in 31 individuals. At least one feature suggestive of MMR was identified in 22 of these specimens. Twenty-seven cases were stained for all four MMR proteins using standard immunohistochemistry (IHC). MMR deficiency was found in 37% (n = 10/27) of cases. Median age of diagnosis was 35 years in the MMR-proficient group and 44 years in the MMR-deficient group, p < 0.008. No other significant differences between the groups were noted. CONCLUSION: MMR deficiency was common in colorectal carcinomas in the older patients in this cohort, but very young indigenous Africans CRCs do not appear to result from mismatch repair gene mutations.

Namaqualand hip dysplasia in South Africa: The molecular determinant elucidated.

BACKGROUND: Namaqualand hip dysplasia (NHD) is a mild form of spondyloepiphyseal dysplasia in which progressive arthropathy of the hip joint is a major manifestation. The disorder was documented in a multigenerational South African (SA) family with antecedents from Namaqualand, a region in the north-west of the country. Linkage analysis revealed a locus that includes the collagen type II gene, COL2A1. OBJECTIVES: To identify the pathogenic COL2A1 variant causing NHD in an SA family. METHODS: One affected male with a clear diagnosis of NHD was selected for whole-exome sequencing (WES) on the Ion Torrent Proton platform. A probe-based assay and direct cycle sequencing were used to confirm that the prioritised variant segregated with the phenotype in the NHD family and was not present in unrelated controls from the same population. RESULTS: WES identified one heterozygous variant, c.2014G>T; p.(Gly672Cys), in the coding sequence of the COL2A1 gene. The variant segregated with NHD in 23 affected family members and was previously reported in a Caucasian male with Perthes disease-like presentation. CONCLUSIONS: It is now possible to provide a molecular diagnosis of NHD before hip problems present. The large, clinically well-characterised NHD family is a valuable resource that could provide more insight into the mechanisms responsible for the variable expression observed in individuals with this variant.

The Incursion and Spread of Highly Pathogenic Avian Influenza H5N8 Clade 2.3.4.4 Within South Africa.

The report of a mass die-off of white-winged terns (Chlidonias leucopterus) along the shores of Lake Victoria in Uganda in January 2017 was a warning that highly pathogenic avian influenza (HPAI) H5N8 clade 2.3.4.4 had entered the avian populations of the African Rift Valley. In early June 2017, Zimbabwe reported an outbreak of the virus in commercial breeder chickens near Harare, and on June 19, 2017, the first case of HPAI H5N8 was confirmed in a broiler breeder operation near Villiers, Mpumalanga Province, South Africa, representing the first ever notifiable influenza in gallinaceous poultry in South Africa. Forty viruses were isolated from wild birds, backyard hobby fowl, zoo collections, commercial chickens, and commercial ostriches over the course of the outbreak and full genomes were sequenced and compared to determine the epidemiologic events in the introduction and spread of clade 2.3.4.4 H5N8 across the country. We found that multiple virus variants were involved in the primary outbreaks in the north-central regions of South Africa, but that a single variant affected the southernmost regions of the continent. By November 2017 only two of the nine provinces in South Africa remained unaffected, and the layer chicken industry in Western Cape Province was all but decimated. Two distinct variants, suggesting independent introductions, were responsible for the first two index cases and were not directly related to the virus involved in the Zimbabwe outbreak. The role of wild birds in the incursion and spread was demonstrated by shared recent common ancestors with H5N8 viruses from West Africa and earlier South African aquatic bird low pathogenicity avian influenza viruses. Improved wild bird surveillance will play a more critical role in the future as an early warning system.

Incursión y propagación del virus de la influenza aviar altamente patógena H5N8 clado 2.3.4.4 en Sudáfrica. El informe de una muerte masiva de fumareles aliblancos (Chlidonias leucopterus) a lo largo de las orillas del lago Victoria en Uganda en enero del 2017 fue una advertencia de que la influenza aviar de alta patogenicidad (HPAI) H5N8, clado 2.3.4.4 había ingresado en las poblaciones de aves del Valle del Rift Africano. A principios de junio del 2017, Zimbabwe reportó un brote del virus en pollos reproductores comerciales cerca de Harare, y el 19 de junio del 2017, el primer caso de influenza aviar de alta patogenicidad H5N8 se confirmó en una operación de pollos de engorde en la provincia de Mpumalanga cerca de Villiers, Sudáfrica, que representa el primer caso de influenza notificable en aves gallináceas en Sudáfrica. Se aislaron cuarenta virus de aves silvestres, aves de traspatio, colecciones de zoológicos, pollos comerciales y avestruces comerciales durante el transcurso del brote. Se secuenciaron los genomas completos y se compararon para determinar los eventos epidemiológicos en la introducción y propagación del subtipo H5N8 clado 2.3.4.4 a través del país. Se encontró que múltiples variantes del virus estaban involucradas en los brotes primarios en las regiones centro y norte de Sudáfrica, pero que una sola variante afectaba a las regiones más al sur del continente. En noviembre de 2017, solo dos de las nueve provincias de Sudáfrica permanecían sin afectarse y la industria de pollos en la Provincia de Cabo Occidental resultó casi diezmada. Dos variantes distintas, que sugieren introducciones independientes, fueron responsables de los dos primeros casos índices y no estuvieron directamente relacionados con el virus involucrado en el brote de Zimbabwe. El papel de las aves silvestres en la incursión y diseminación fue demostrado por los ancestros comunes compartidos con los virus H5N8 de África Occidental y los virus de la influenza aviar de baja patogenicidad de aves acuáticas de Sudáfrica detectados anteriormente. La mejora de la vigilancia de aves silvestres jugará un papel más crítico en el futuro como un sistema de alerta temprana.

A randomised comparison of bolus phenylephrine and ephedrine for the management of spinal hypotension in patients with severe preeclampsia and fetal compromise.

BACKGROUND: Studies in healthy patients undergoing elective caesarean delivery show that, compared with phenylephrine, ephedrine used to treat spinal hypotension is associated with increased fetal acidosis. This has not been investigated prospectively in women with severe preeclampsia. METHODS: Patients with preeclampsia requiring caesarean delivery for a non-reassuring fetal heart tracing were randomised to receive either bolus ephedrine (7.5-15mg) or phenylephrine (50-100µg), to treat spinal hypotension. The primary outcome was umbilical arterial base excess. Secondary outcomes were umbilical arterial and venous pH and lactate concentration, venous base excess, and Apgar scores. RESULTS: Among 133 women, 64 who required vasopressor treatment were randomised into groups of 32 with similar patient characteristics. Pre-delivery blood pressure changes were similar. There was no difference in mean [standard deviation] umbilical artery base excess (-4.9 [3.7] vs -6.0 [4.6] mmol/L for ephedrine and phenylephrine respectively; P=0.29). Mean umbilical arterial and venous pH and lactate concentrations did not significantly differ between groups (7.25 [0.08] vs 7.22 [0.10], 7.28 [0.07] vs 7.27 [0.10], and 3.41 [2.18] vs 3.28 [2.44] mmol/L respectively). Umbilical venous oxygen tension was higher in the ephedrine group (2.8 [0.7] vs 2.4 [0.62]) kPa, P=0.02). There was no difference in 1- or 5-min Apgar scores, numbers of neonates with 1-min Apgar scores <7 or with a pH <7.2. CONCLUSIONS: In patients with severe preeclampsia and fetal compromise, fetal acid-base status is independent of the use of bolus ephedrine versus phenylephrine to treat spinal hypotension.

Maternal cardiac output response to colloid preload and vasopressor therapy during spinal anaesthesia for caesarean section in patients with severe pre-eclampsia: a randomised, controlled trial.

We examined the haemodynamic effects of colloid preload, and phenylephrine and ephedrine administered for spinal hypotension, during caesarean section in 42 women with severe early onset pre-eclampsia. Twenty patients with pre-delivery spinal hypotension were randomly allocated to receive an initial dose of either 50 µg phenylephrine or 7.5 mg ephedrine; the primary outcome was percentage change in cardiac index. After a 300-ml colloid preload, mean (SD) cardiac index increased from 4.9 (1.1) to 5.6 (1.2) l.min-1 .m-2 (p < 0.01), resulting from an increase in both heart rate, from 81.3 (17.2) to 86.3 (16.5) beats.min-1 (p = 0.2), and stroke volume, from 111.8 (19.0) to 119.8 (17.9) ml (p = 0.049). Fourteen (33%) and 23 (54.8%) patients exhibited a stroke volume response > 10% and > 5%, respectively; a significant negative correlation was found between heart rate and stroke volume changes. Spinal hypotension in 20 patients was associated with an increase from baseline in cardiac index of 0.6 l.min-1 .m-2 (mean difference 11.5%; p < 0.0001). After a median [range] dose of 50 [50-150] µg phenylephrine or 15 [7.5-37.5] mg ephedrine, the percentage change in cardiac index during the measurement period of 150 s was greater, and negative, in patients receiving phenylephrine vs. ephedrine, at -12.0 (7.3)% vs. 2.6 (6.0)%, respectively (p = 0.0001). The percentage change in heart rate after vasopressor was higher in patients receiving phenylephrine, at -9.1 (3.4)% vs. 5.3 (12.6)% (p = 0.0027), as was the change in systemic vascular resistance, at 22.3 (7.5) vs. -1.9 (10.5)% (p < 0.0001). Phenylephrine effectively reverses spinal anaesthesia-induced haemodynamic changes in severe pre-eclampsia, if left ventricular systolic function is preserved.

Promoter region variation in NFE2L2 influences susceptibility to ototoxicity in patients exposed to high cumulative doses of cisplatin.

Ototoxicity is a disabling reaction to cisplatin chemotherapy. Much of the inter-individual variability in the development of hearing impairment among cisplatin-receiving patients has not been fully accounted for. In particular, little is known about the pharmacogenomics of cisplatin-induced ototoxicity. This study sought to investigate the role of variation in five candidate genes in a cohort of South African cancer patients. Five variants within the candidate genes were genotyped in 214 patients, of which SLC22A2 rs316019 and NFE2L2 rs6721961 associated with reduced rates of ototoxicity. In the patients who were exposed to cumulative cisplatin doses ⩾200 mg m-2 (n=113), the variant rs6721961 associated with ototoxicity according to three different grading scales of hearing loss (ASHA, P=0.005; Chang, P=0.028; CTCAE, P=0.004). The NFE2L2 promotor variant rs6721961 may therefore be protective against hearing loss in cisplatin-receiving cancer patients.

An inferential comparison between the capabilities and achievements of 1st-year medical and nursing students at the University of the Free State, Bloemfontein, South Africa

Background. Research indicates that academic stressors; living circumstances; working conditions and where students undertake leisure activities affect academic performance; capabilities and achievements (functionings). Objective. To investigate how 1st-year medical and nursing students perceived their own capabilities compared with their actual achievements (functionings). The article focuses on the achievements (functionings); as these students were admitted through a selection process; indicating their potential capability to succeed. Methods. In this descriptive; comparative study; all 1st-year medical and nursing students at the University of the Free State; Bloemfontein; South Africa were invited to complete a validated questionnaire to reflect their capabilities (scope) and achievements (outcomes). The questionnaire incorporated seven domains: happiness; achievements; health; intellect; social relations; environment and integrity. Data were analysed using descriptive statistics (frequencies; medians; means; standard deviations and standard errors). Results. All respondents valued the domains positively with regard to the outcomes (functionings). On average; nursing students valued the domains 17.4% lower than the medical students. Integrity was valued the highest by all. Health scored the lowest in the medical group; and environment (where students study and undertake leisure activities) the lowest in the nursing group. Conclusions. Medical schools should include wellness in their curricula; limit the degree of physical and emotional exhaustion associated with training; and have realistic expectations of students. Programmes should allocate enough time for students to manage their time well to take part in physical activity and eat healthy foods. Nursing students' work environment should improve. More time should be made available for leisure activities and improvement to students' study environment

Spondyloepimetaphyseal dysplasia with joint laxity (Beighton type); mutation analysis in eight affected South African families.

Spondyloepimetaphyseal dysplasia with joint laxity (SEMD-JL), type 1 is an autosomal recessive disorder which has been identified in more than 30 affected children in the Afrikaans-speaking community of South Africa. Sequencing of B3GALT6 revealed a specific mutation, c.235A > G, in homozygous form in four families, while three others were compound heterozygotes for this mutation in combination with the c.200C > T mutation. In addition, a proband from one family carried the c.16C > T mutation combined with c.200C > T. In a series of five Iranian persons, mutations in B3GALT6 have been implicated in a syndrome characterised by skeletal abnormalities with intellectual disability, bone and connective tissue fragility. Other mutations in B3GALT6 resulted in the classical SEMD-JL phenotype in seven Japanese families and in a syndrome which has been likened to a progeroid form of Ehlers-Danlos syndrome (EDS). It is evident that there is considerable intragenic heterogeneity in B3GALT6. One of the mutations, c.200C > T, in the affected South Africans was also present in one of the Japanese persons and the respective phenotypes were identical. The multiplicity of allelic mutations and the phenotypic differences in the affected persons supports the concept that a spectrum of connective tissue disorders is programmed by mutations in B3GALT6.

No evidence of genetic anticipation in a large family with Lynch syndrome.

Lynch syndrome is the commonest inherited cause of colorectal cancer (CRC). Genetic anticipation occurs when the age of onset of a disorder decreases in successive generations. It is controversial whether this occurs in Lynch syndrome. Previous studies have included heterogenous groups of subjects from multiple families, including subjects with a clinical diagnosis (based on family history) as well as those with proven germline mismatch repair gene mutations. The purpose of this study was to determine whether genetic anticipation occurs in mismatch repair gene carriers from a single Lynch syndrome family. This study includes members of a single family known to carry an MLH1 gene mutation who are proven germline mutation carriers or obligate carriers (based on their offspring's mutation status). Evidence of genetic anticipation (determined by age of onset of first CRC) was sought in two ways: Firstly, subjects were grouped as parent-child pairs and individuals were compared with their own offspring; secondly they were grouped by generation within the family tree. The Kaplan-Meier technique was used to adjust for variable follow up times. The family tree consisted of 714 subjects. Ninety-two subjects over five generations were included in the study. There was no evidence of genetic anticipation over the generations. (P = 0.37). Similarly, in the 75 parent-child pairs identified, age of onset of CRC was similar for parents and children (P = 0.51). We could not identify any evidence of genetic anticipation in mutation carriers from a single family with Lynch syndrome.

Lynch syndrome: the influence of environmental factors on extracolonic cancer risk in hMLH1 c.C1528T mutation carriers and their mutation-negative sisters.

Lynch Syndrome (LS) is a cancer susceptibility syndrome caused mostly by mutations in the mismatch repair genes, hMLH1, hMSH2 and hMSH6. Mutation carriers are at risk of colorectal and endometrial cancer and, less frequently, cancer of the ovaries, stomach, small bowel, hepatobiliary tract, ureter, renal pelvis and brain. The influence of environmental factors on extracolonic cancer risk in LS patients has not been investigated thus far. The aim of this study was to investigate some of these factors in South African females carrying the hMLH1 c.C1528T mutation and their mutation-negative relatives. Data were collected from 87 mutation-positive females and 121 mutation-negative female relatives regarding age, cancer history, hormonal contraceptive use, parity, duration of breast feeding, height, weight and age at first birth, last birth, menarche and menopause. Influence of these factors on cancer risk was analysed by mixed-effects generalised linear models. Extracolonic cancer occurred in 14% (12/87) of mutation-positive females versus 7% (8/121) of mutation-negative females, (P = 0.0279, adjusted for age and relatedness between women). Breast cancer was the most common extracolonic cancer. An association was found for oral contraceptive use and extracolonic cancer risk in mutation-negative females only. No association was found for any of the other risk factors investigated, when adjusted for age. This might be due to the scarcity of extracolonic cancers in our data. Future knowledge on the influence of additional environmental factors on cancer risk in LS females can lead to evidence-based lifestyle advice for mutation carriers, thereby complementing the prevention strategies available today. In addition, it can contribute to an integrated model of cancer aetiology. Therefore, this study should be taken as a thrust for further research.

Clinical and pathological features of hereditary mixed polyposis syndrome: report on a South African family.

BACKGROUND: Hereditary mixed polyposis syndrome is characterised by multiple large-bowel polyps of differing histological types including a mixture of atypical juvenile polyps, hyperplastic polyps and adenomas. Affected individuals are thought to have an increased risk of malignancy, possibly via the juvenile polyposis pathway. METHODS: A 51-year-old woman (with a history of a colectomy for polyps during childhood) presented with rectal bleeding. Endoscopy demonstrated small rectal polyps which were hyperplastic on histology. A family tree was drawn up and the three children of the proband underwent flexible sigmoidoscopy. RESULTS: Endoscopic surveillance of the three children revealed one who had a similar phenotype to the mother. This child underwent colectomy and ileorectal anastomosis. The pathological specimen revealed more than 70 polyps, with a combination of juvenile retention, hyperplastic, adenomatous and inflammatory polyps. A second child had multiple small hyperplastic polyps, and the third had a normal colon. Although the gene locus for the disorder has been mapped, neither the gene nor the disease-causing mutation has been defined. CONCLUSION: A rare inherited polyposis syndrome has been identified in a South African family. Where clinical suspicion of a possible inherited condition exists, investigating at-risk first-degree relatives confirms the inherited nature of the disease. It is possible to use genetic haplotyping (i.e. with a range of markers in the area of the gene) to provide statistical risk to immediate relatives and therefore those at highest risk.

The extracolonic cancer spectrum in females with the common 'South African' hMLH1 c.C1528T mutation.

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant disease, characterized by the occurrence of predominantly colon and endometrial cancer and, less frequently, cancer of the small bowel, stomach, hepatobiliary tract, ureter, renal pelvis, ovaries and brain. The phenotypic diversity may partially be explained by allelic heterogeneity. The aim of this study was to investigate the frequency of extracolonic cancers in a cohort of females sharing the same c.C1528T disease-predisposing mutation in the hMLH1 gene. Data on cancer history were obtained from 87 mutation-positive females and 121 mutation-negative sisters, as a control group. Testing for microsatellite instability (MSI) and expression of the wild-type hMLH1 allele was performed on extra-colonic tumour tissue blocks of mutation-positive individuals. Extracolonic cancer occurred in 14% (12/87) of mutation-positive females vs. 7% (8/121) of mutation-negative females (P = 0.10). Multiple primary cancers occurred at a significantly higher incidence in the first group. Breast cancer, which was the most frequent extra-colonic cancer in mutation positive females (53%), occurred at a young age, and occurred bilaterally in two out of seven cases. Involvement of the hMLH1 gene was confirmed in five out of seven cases of breast cancer, two cases of endometrial cancer, one case of ovarian cancer and one case of renal cell carcinoma, by detecting immunohistochemical compromise of the gene product. Although the study might not have been adequately statistically powered (to provide a significant P value), the noteworthy findings in this study include the confirmation of a range of Lynch II type cancers in a cohort we previously thought was wholly predisposed to Lynch I features, and a confirmation of breast cancer as part of the spectrum of Lynch syndrome cancers affecting women.

Arg120stop nonsense mutation in the RP2 gene: mutational hotspot and germ line mosaicism?

Mutations in the RP2 gene account for up to 20% of X-linked recessive retinitis pigmentosa (RP). Arg120stop is to date the most frequently reported mutation found in RP2. Mutation screening was performed during the course of a large screening program of retinal degenerative disorders (RDDs) in South Africa using exon 1 and 2 of RP2 in 20 unrelated families with an X-linked mode of retinal degenerative inheritance. Direct sequencing analysis revealed a C-->T transition at position 358 in the proband in a family of German origin. Subsequent analysis revealed that this Arg120stop mutation cosegregated with the disease in an additional affected family member. The nonsense mutation, Arg120stop, could not however, be detected in the somatic cells of the obligate carrier female. This, the first report of a germ line mutation for a family with RP, has many implications for genetic counseling of retinal degeneration (RD). To avoid inaccurate risk assessment for RP due to epigenetic events, such as the rare occurrence of germ line mosaicism, genetic counseling in families with XLRP should always be guided by molecular testing.

Analysis of RPGR in a South African family with X-linked retinitis pigmentosa: research and diagnostic implications.

Analysis of exon ORF15 of the RPGR gene has revealed a novel mutation in a South African family with X-linked retinitis pigmentosa (XLRP), which has implications for the rest of the family in terms of pre-symptomatic testing. The ability to test for this mutation will be beneficial for the accurate determination of carrier status in female relatives who may have been unaware of their risk before this study was performed. This work also highlights the need to be aware of the ramifications of mutation testing in what may appear to be small families. This is the first report of an RPGR ORF15 mutation in a South African family of mixed ancestry.