Detection of Transversions and Transitions in HBG2 Cis-Elements Associated with Sickle Cell Allele in Ghanaians.

Short tandem repeats located 5' prime to the ß-globin gene, have been observed to be in linkage disequilibrium with the HbS allele, and thought to affect the severity of sickle cell disease. Here, we report on new mutants within the HBG2 region that may impact sickle cell disease. To determine the cis-acting elements microsatellites, indels and single nucleotide polymorphisms (SNPs), within the HBG2 region by sequencing, in subjects with sickle cell disease. The case-control study was located at the Center for Clinical Genetics, Sickle cell unit, Korle-Bu Teaching Hospital. A questionnaire was used for demographic data and clinical information. Hematological profile (red blood cell, white blood cell, platelet, hemoglobin and mean corpuscular volume) were assessed in 83 subjects. A set of 45 samples comprising amplified DNA on the HBG2 gene from HbSS (22), HbSC (17) and 6 controls (HbAA) were sequenced. Differences in the microsatellite region between sickle cell disease (SCD) (HbSS and HbSC) genotypes and control subjects were identified by counting and assessed by Chi-square analysis. Red blood cells, hematocrit, platelets, white blood cells and hemoglobin indices differed in genotypic groups. HbSS subjects were affirmed to have severer hemolytic anemia than HbSC subjects. Two indels (T1824 and C905) were seen in both SS and SC genotypes. Two peculiar SNPs: G:T1860 (transition) and A:G1872 transversions were found within the HBG2 gene that were significantly associated with the HbSS genotype (Fisher's exact test, p = 0.006) and HbS allele respectively (Fisher's exact test, p = 0.006). Cis-acting elements in HbSS and HbSC were different and may contribute to the phenotype seen in the disease state.

Effects of factor v Leiden polymorphism on the pathogenesis and outcomes of preeclampsia.

BACKGROUND: Factor V Leiden polymorphism is a well-recognized genetic factor in the etiology of preeclampsia. Considering that Ghana is recording high incidence of preeclampsia, we examined if factor V Leiden is a contributory factor to its development and pregnancy outcomes. METHODS: STROBE consensus checklist was adopted to recruit eighty-one (81) consenting subjects after ethical clearance. Subjects were followed up till delivery to obtain outcomes of PE. Routine blood chemistry and proteinuria were done on all samples. Factor V Leiden was characterized by polymerase chain reaction and restriction fragment length polymorphism (RFLP). The data was captured as protected health information (PHI) and analyzed with SPSS version 22. RESULTS: Overall allelic frequencies found in FVL exon 10 were 0.67 and 0.33 for G and A alleles respectively. The FVL mutation was more in PE and hypertensive patients. Increased white blood cells, increased uric acid and a three - fold increment of AST / ALT ratio was observed in PE cases when stratified by FVL exons (exon 8 and 10). Significant differences were also observed between FVL and age, systolic blood pressure (SBP), diastolic blood pressure (DBP), liver enzymes, white blood cells (wbc), hemoglobin levels. CONCLUSION: FVL mutation allele frequency was 0.33, a first report. The mutation was associated with increased uric acid, liver enzymes and blood cell indices suggestive of acute inflammation.

A-61C and C-101G Hp gene promoter polymorphisms are, respectively, associated with ahaptoglobinaemia and hypohaptoglobinaemia in Ghana.

We have investigated the genetic basis for the Hp0 phenotype amongst 123 randomly selected Ghanaians. A total of 17 individuals were determined to be Hp0 phenotype, based on the classical method for Hp phenotyping of Hb-supplemented plasma. Out of the 17 Hp0 individuals, nine subjects were further classified as ahaptoglobinaemic and eight as hypohaptoglobinaemic by Western blots and double immunodiffusion. We identified three previously known base substitutions (A-55G, A-61C and T-104A) and three new ones (C-101G, T-191G and C-242T) within the 5' flanking region of the Hp gene. The A-61C base substitution significantly decreased transcriptional activity and was associated strongly with Hp2 allele and ahaptoglobinaemia. The C-101G substitution was similar in transcriptional activity to the wild-type and was associated with Hp1S allele and hypohaptoglobinaemia. The Hpdel allele seen in Asian populations was absent. We conclude that the Hp0 phenotype in Ghana has a genetic basis that differs significantly from that seen in Asia.

Haptoglobin phenotypes in HIV-1-seropositive patients in Ghana: decreased risk for Hp0 individuals.

Plasma haptoglobin phenotypes were determined by polyacrylamide gel electrophoresis, followed by benzidine staining for 58 HIV-1 seropositive Ghanaians and 79 randomly selected age-matched controls. Hp0 was present in only 14% of HIV-1 seropositive individuals compared with more than 40% of the controls. The Hp0 individuals showed a highly significant reduced risk for HIV-1 infection (OR = 0. 21, 95% CI = 0.09-0.51, p = 0.0002). Hp0 may have a protective effect in HIV-1 infection.

Haptoglobin 1-1 is associated with susceptibility to severe Plasmodium falciparum malaria.

The haptoglobin (Hp) phenotypes were determined by polyacrylamide-gel electrophoresis in plasma samples obtained in 1997 from 113 Plasmodium falciparum malaria patients (aged 1-12 years) with strictly defined cerebral malaria, severe malarial anaemia, or uncomplicated malaria and 42 age-matched healthy controls from the same area (coastal Ghana). Hp1-1 was significantly more prevalent among the patients (43%) than among healthy controls (7.1%), whereas Hp2-1 and Hp2-2 were underrepresented among the patients (11% and 2%, respectively) compared to the control donors (33% and 14%, respectively). No significant difference in frequency of Hp0 was observed between patients and controls. Among the malaria patients, the Hp1-1 phenotype was significantly more prevalent among patients with the complications of cerebral malaria and severe anaemia compared to patients with uncomplicated disease, whereas the reverse was seen with respect to Hp2-1 and Hp2-2. Our data suggest that the Hp1-1 phenotype is associated with susceptibility to P. falciparum malaria in general, and to the development of severe disease in particular.

Haptoglobin polymorphism in human immunodeficiency virus infection: Hp0 phenotype limits depletion of CD4 cell counts in HIV-1-seropositive individuals.

Patients seropositive for human immunodeficiency virus (HIV) type 1 and seronegative control subjects were categorized by their haptoglobin phenotypes, which were determined by electrophoresis of hemoglobin-supplemented plasma samples followed by benzidine staining. The CD4 cell counts, determined by flow cytometry from peripheral blood mononuclear cells according to subject categories, were severely diminished in seropositive patients with the Hp2-2 phenotype (P<.025). In contrast, the CD4 cell counts for patients with the Hp0 phenotype remained relatively high (P<.025), compared with those of the controls. In seronegative patients, CD4 cell counts were generally high (P<.005), but they were more elevated in subjects with Hp2-2 and Hp1-1, although the differences were not significant. Thus, the Hp2-2 phenotype is associated with poor outcome in HIV-1 infection, whereas the Hp0 phenotype is associated with a better prognosis once the patient is infected with HIV-1. Haptoglobin polymorphism plays a significant role in HIV-1 infection and transmission.

Acute effects of five Ghanaian carbohydrate diets on serum glucose, triglyceride and insulin in NIDDM.

Glycemic indices have been used to predict useful carbohydrate sources of food for patients with non-insulin-dependent diabeties mellitus (NIDDM) on dietary management programs. The present study has revealed that glycemic indices alone are not adequate predictors of useful carbohydrate meal sources. We observed for the first time that glycemic indexes inversely correlate with triglyceride indices. In our test mixed meals varying in five Ghanaian carbohydrate food types for nine non-insulin dependent diabetics, the correlation between glycemic and triglyceride indices was (r = -0.63; P = 0.005). The atherogenic potential of triglyceride makes a critical review of the sole use of glycemic indices as useful carbohydrate predictors necessary. We also observed that unripened big plantains (a staple Ghanaian food) could be a useful carbohydrate source for NIDDM patients.

Blood glucose responses to mixed Ghanaian diets in healthy adult males.

The blood glucose responses to five Ghanaian carbohydrate sources, unripe plantain, Ga kenkey, Gari, rice and yam, as part of mixed meals were determined in ten healthy young nondiabetic adult males aged 25.6 +/- 2.6 years with a BMI of 20.9 +/- 2.4 kg/m2. Ga kenkey showed the least changes in blood glucose responses as measured by the glycemic index. Yam exhibited the least favourable blood glucose responses. Significant difference were observed between the glycemic indices of kenkey and yam; Kenkey and gari (p < 0.01); rice and yam, plantain and yam (p < 0.05). Further studies of these carbohydrate sources are required in diabetics to ascertain their suitability as carbohydrate sources in Ghanaian diabetics.

Sequence requirement for nucleolar localization of rat ribosomal protein L31.

Nucleolar localization of the fusion protein of rat ribosomal protein L31 and beta-galactosidase was investigated by immunocytochemical means, using the ribosomal protein deletion or substitution mutants that were transiently expressed in COS-1 cells. The signal responsible for nucleolar localization is encoded by the amino acid residues 87 to 92, RLSRKR, located near the C terminus of the ribosomal protein. Mutation of residues 87R and 90R prevented nucleolar localization, whereas mutations including 90R prevented nuclear and nucleolar localization. Further mutations in the sequence revealed that the tetrapeptide RLSR, which was amenable to substitutions at the L and S positions, is critical for nucleolar localization.

Assessment of anthropometric measurements, blood analytes and liver enzymes in Ghanaian alcoholics.

Anthropometric measurements of alcoholics and non alcoholics of similar economic background were compared and the results reveal that there are no marked differences between the two. However, the biochemical analyses indicates that alcohol predisposes to fat storage, may contribute to iron deficiency and plays a direct etiologic role in liver disease.

Biochemical and haematological markers of alcohol intake in Ghanaians.

The serum gamma-glutamyltransferase (GGT), aspartate aminotransferase (AST), urate and triglyceride and mean cell volume (MCV) were determined in 60 total abstainers, 56 social drinkers and 100 alcoholics. Both enzymes and urate showed progressive rise with increasing alcohol intake. The mean cell volume was only moderately elevated. Gamma-glutamyltransferase (GGT), aspartate aminotransferase (AST), and urate are sensitive enough to detect people who take in alcohol regularly and yet may be regarded as normal and not alcohol dependent.

Nutritional status and levels of liver enzymes in Ghanaian alcoholics

The well nourished alcoholics appeared to have some protection from alcoholic liver damage; although their fat levels were higher which may predispose to cardiac disease. Alcoholics therefore; show some degree of impaired liver function which is more severe among those who are malnourished