Anaemia,iron deficiency and a common polymorphism of iron‐regulation,TMPRSS6 rs855791, in Rwandan children

Anaemia in children living in sub‐Saharan Africa is common, but its causes are diverse. In 545 children below 5 years of age from rural southern Rwanda, we assessed the role of iron deficiency (ID) and of the TMPRSS6 736(V) (rs855791) allele, known to reduce iron status and haemoglobin (Hb) levels, in anaemia and Hb concentrations. Anaemia (Hb <11 g/dl) was present in 34.4% of the children and ID (ferritin <12 ng/ml) in 17.6%. The TMPRSS6 736(V) allele was uncommon (allele frequency, 0.096) and not associated with ID. In multivariate analysis, ID was positively associated with anaemia (adjusted odds ratio, 1.67) to an extent comparable with α⁺‐thalassaemia, breastfeeding, inflammation and low household income, but the odds were substantially higher in Plasmodium falciparum infection (adjusted odds ratio, 10.3). These findings were verified in a multivariate analysis of Hb concentrations. The TMPRSS6 736(V) allele only tended to be associated with low Hb levels. TMPRSS6 736(V) is comparatively rare among Rwandan children and may only slightly contribute to low Hb concentrations. Preventable causes of anaemia, notably ID and P. falciparum infection, largely outweigh its impact and need to be addressed to improve the haematological status of children in the study area.     

Novel biosensor-based microarray assay for detecting rs8099917 and rs12979860 genotypes

AIM: To evaluate a novel biosensor-based microarray (BBM) assay for detecting rs12979860 and rs8099917 genotypes.METHODS: Four probes specific for rs8099917C/T or rs12979860G/T detection and three sets of quality control probes were designed, constructed and arrayed on an optical biosensor to develop a microarray assay. Two sets of primers were used in a one tube polymerase chain reaction (PCR) system to amplify two target fragments simultaneously. The biosensor microarray contained probes that had been sequenced to confirm that they included the rs8099917C/T or rs12979860G/T alleles of interest and could serve as the specific assay standards. In addition to rehybridization of four probes of known sequence, a total of 40 clinical samples collected from hepatitis C seropositive patients were also tested. The target fragments of all 40 samples were amplified in a 50 μL PCR system. Ten μL of each amplicon was tested by BBM assay, and another 40 μL was used for sequencing. The agreement of the results obtained by the two methods was tested statistically using the kappa coefficient. The sensitivity of the BBM assay was evaluated using serial dilutions of ten clinical blood samples containing 10³-10⁴ white cells/μL.RESULTS: As shown by polyacrylamide gel electrophoresis, two target segments of the interleukin 28B-associated polymorphisms (SNPs) were successfully amplified in the one-tube PCR system. The lengths of the two amplified fragments were consistent with the known length of the target sequences, 137 and 159 bps. After hybridization of the PCR amplicons with the probes located on the BBM array, the signals of each allele of both the rs8099917 SNPs and rs12979860 SNPs were observed simultaneously and were clearly visible by the unaided eye. The signals were distinct from each other, could be interpreted visually, and accurately recorded using an ordinary digital camera. To evaluate the specificity of the assay, both the plasmids and clinical samples were applied to the microarray. First, 30 PCR amplicons of the various SNP alleles were hybridized on the BBM microarray. Full agreement between plasmids and the BBM assay was observed, with 30/30 correct matches (100%). The kappa value for the BBM assay with plasmids was 1.00 (P < 0.05). For the 40 clinical blood samples, the BBM assay hybridization and direct sequencing results were compared for each amplicon. For patient blood samples, agreement was 28/28 for rs8099917T/T, 9/11 for rs8099917T/G, 1/1 for rs8099917G/G, 24/24 for rs12979860C/C, 11/14 for rs12979860C/T, and 2/2 for rs12979860T/T. Only five clinical samples of amplicon assay and direct sequencing results were discordant and heterozygotes: 2/11 rs8099917T/G and 3/14 rs12979860C/T. The agreement of outcomes between BBM assay and direct sequencing for the detection of rs8099917 and rs12979860 was 95% and 92.5%, respectively; and the corresponding kappa values were 0.88 and 0.85 (A kappa value > 0.75 was defined as substantial agreement). The BBM assay and sequencing had similar specificities for detection and identification of the two SNPs and their alleles. The sensitivity evaluation showed that the BBM assay could detect and identify SNP sequences present in blood samples containing as few as 10² white blood cells/μL.CONCLUSION: This biosensor microarray assay was highly specific, sensitive, rapid and easy to perform. It is compatible with clinical practice for detection of rs8099917 and rs12979860.     

Association of IL-13 rs20541 and rs1295686 variants with symptomatic asthma in a Saudi Arabian population

Objective: Interleukin 13 (IL-13) plays a critical pro-inflammatory role in asthma. Several single nucleotide polymorphisms (SNPs) are associated with asthma susceptibility in specific populations; however, further replicative studies in other ethnic groups are mandatory. Methods: The association between IL-13 SNPs rs762534, rs20541, rs1295686, and rs1800925 (risk alleles A, A, T, and A, respectively) and asthma predisposition in a Saudi Arabian cohort was examined via a case–control cross-sectional study. Results: The frequencies of alleles between asthmatics and control populations were significantly different for rs20541 and rs1295686 SNPs (p < 0.001), whereas the frequencies of genotypes between asthmatics and controls were significantly different only for rs20541. The association of the risk (minor) alleles with asthma was examined using the dominant genetic model. Individuals with at least one copy of the risk alleles A (for rs20541) and T (for rs1295686) had significantly greater odds of being asthmatic (OR = 2.13, 95% CI = 1.39–3.26, p < 0.0001; OR = 1.69, 95% CI = 1.12–2.54, p = 0.008) relative to their most common homozygous genotypes. On the other hand, the minor A alleles for rs762534 and rs1800925 were not significantly associated with asthma risk. Regarding haplotype association analysis, individuals with at least one copy of the minor “risk” allele for both rs20541 and rs1295686 (CATG and CATA, respectively) had greater odds of being asthmatic relative to CGCG haplotype; however, this trend was not statistically significant (p > 0.3). Conclusions: IL-13 minor T and A alleles for rs1295686 and rs20541, respectively, were associated with significantly higher risk of asthma in the Saudi Arabian population.     

Association between APE1 rs1760944 and rs1130409 polymorphism with prostate cancer risk: A systematic review and meta-analysis

Background:Recently, some studies have suggested that the association of apurinic/apyrimidinic endonuclease 1 (APE1) gene polymorphism with prostate cancer (PCa) risk, but there are still some controversies. Hence, we elaborated the relationship between APE1 rs1760944 and rs1130409 gene and PCa risk through systematic literature review and meta-analysis.Methods:As of March 2020, EMBASE, PubMed, the Cochrane Library, Science Direct/Elsevier, MEDLINE and CNKI were used for systematic literature retrieval to investigate the correlation between APE1 rs1760944 and rs1130409 gene polymorphism with PCa risk. Meta-analysis was performed using Review Manager and Stata software.Results:Seven studies were distinguished, consists of 1769 cases of PCa patients and 2237 normal controls. Our results illustrated that there are significant correlation between the APE1 rs1760944 gene polymorphism and PCa in all genetic models (P < .05). The combined odds ratios and 95% confidence intervals were as follows: Additive model (ORs 0.62, 95%, CI [0.39, 0.97]); Codominant model (ORs 0.74, 95% CI [0.58, 0.95]); Dominant model (ORs 0.75, 95%, CI [0.59, 0.95]); Recessive model (ORs 0.63, 95% CI [0.41, 0.96]); Allele model (ORs 0.78, 95% CI [0.65, 0.94]). There also have significant associations between APE1 rs1130409 polymorphisms and PCa in all genetic models (P < .05). The combined odds ratios and 95% confidence intervals were as follows: Additive model (ORs 1.37, 95%, CI [1.01, 1.85]); Codominant model (ORs 1.21, 95% CI [1.01, 1.44]); Dominant model (ORs 1.33, 95%, CI [1.02, 1.73]); Recessive model (ORs 1.74, 95% CI [1.06, 2.85]); Allele model (ORs 1.14, 95% CI [1.00, 1.29]).Conclusion:This study suggests that APE1 rs1760944 polymorphisms might be a protective factor of PCa, and APE1 rs1130409 is suggested to be a risk factor of PCa. APE1 rs1760944 and rs1130409 polymorphisms may be used in the risk assessment of PCa.     

IL28RA polymorphism (rs10903035) is associated with insulin resistance in HIV/HCV‐coinfected patients

Hepatitis C virus (HCV) infection is associated with insulin resistance (IR), although mechanisms leading to IR in these patients are not completely understood. The aim of this study was to evaluate the association of interleukin 28B (IL28B) and interleukin 28 receptor alpha (IL28RA) polymorphisms with IR among human immunodeficiency virus (HIV)/HCV‐coinfected patients. We carried out a cross‐sectional study on 203 patients. IL28B (rs8099917) and IL28RA (rs10903035) polymorphisms were genotyped by GoldenGate^® assay. IR was defined as homeostatic model assessment (HOMA) values ≥3.00. Univariate and multivariate generalized linear models (GLM) were used to compare HOMA values and the percentage of patients with IR according to IL28B and IL28RA genotypes. In total, 32% (n = 65/203) of the patients had IR. IL28B rs8099917 TT was not significantly associated with HOMA values and IR. In contrast, rs10903035 AA was significantly associated with high HOMA values taking into account all patients (P = 0.024), as well as the subgroups of patients with significant fibrosis (P = 0.047) and infected with HCV genotype 3 (P = 0.024). Additionally, rs10903035 AA was significantly associated with IR (HOMA ≥3.00) in all patients (adjusted odds ratio (aOR) = 2.02; P = 0.034), in patients with significant fibrosis (aOR = 2.86; P = 0.039) and HCV genotype 3 patients (aOR = 4.89; P = 0.031). In conclusions, IL28RA polymorphism (rs10903035) seems to be implicated in the glucose homeostasis because AA genotype increases the likelihood of IR, but this association was different depending on hepatic fibrosis and HCV genotype.     

Distribution of alleles,genotypes and haplotypes of the CYP2B6 (rs3745274; rs2279343) and CYP3A4 (rs2740574) genes in the Malian population: Implication for pharmacogenetics

Cytochrome P450 enzymes play a central role in the phase I biotransformation process of a wide range of compounds, including xenobiotics, drugs, hormones and vitamins. It is noteworthy that these enzymes are highly polymorphic and, depending on the genetic makeup, an individual may have impaired enzymatic activity. Therefore, the identification of genetic variants in these genes could facilitate the implementation of pharmacogenetic studies and genetic predisposition to multifactorial diseases. We have established the frequencies of CYP2B6 (rs3745274; rs2279343) and CYP3A4 (rs2740574) alleles and genotypes in 209 healthy Malian subjects using TaqMan drug metabolism genotyping assays for allelic discrimination. Allele frequencies were 37% for CYP2B6 rs3745274; 38% for CYP2B6 rs2279343; and 75% for CYP3A4 rs2740574 respectively. Overall, the frequencies observed in Mali are statistically comparable to those reported across Africa except North Africa. The major haplotypes in CYP2B6 rs3745274 and CYP2B6 rs2279343 were represented by GA (60.24%) followed by TG (35.36%). We noted a strong linkage disequilibrium between CYP2B6 rs3745274 and CYP2B6 rs2279343 with D’ = 0.91 and r² = 0.9. The frequencies of the genotypic combinations were 43.5% (GT/AG), 37.3% (GG/AA) and 11.5% (TT/GG) in the combination of CYP2B6-rs3745274 and CYP2B6-rs2279343; 26.8% (GT/CC), 25.4%, (GT/CT), 17.2% and GG/CT in the combination CYP2B6-rs3745274-CYP3A4-rs2740574; 26.8% (AG/CC), 23.9% (AA/CC), 19.1% (AG/CT), and 11% (AA/CT) in the combination CYP2B6-rs2279343-CYP3A4-rs2740574, respectively. The most common triple genotype was GT/AG/CC with 24.9%, followed by GG/AA/CC with 23.9%, GT/AG/CT with 16.7%, and GG/AA/CT with 10%. Our results provide new insights into the distribution of these pharmacogenetically relevant genes in the Malian population. Moreover, these data will be useful for studies of individual genetic variability to drugs and genetic predisposition to diseases.