Homozygous Subjects Research Articles

Epidemiological profile of severe malaria and sickle cell disease in children at the mother and child university hospital center Jeanne Ebori foundation of libreville from 2020 to 2021

Background: Hemoglobinopathies represent the most common genetic diseases worldwide. In Gabon, the clinico-biological profile of patients with homozygous hemoglobin S or those with AS sickle cell traits, faced with this prevalence of serious malaria, remains unknown today. The objective was to evaluate the complications of severe malaria in SS homozygous sickle cell patients and those carrying AS sickle cell traits. Methods: This is an observational, retrospective study, with descriptive and analytical aims which took place from January 2020 to October 2021. The parameters studied were socio-demographic, clinical and paraclinical data, the diagnosis chosen, therapeutic data and evolution. Results: severe neurological form of malaria was the most common criterion with a frequency of 41.7%, followed by parasitic forms 35.8% and anemic forms 21.8%. Among AS heterozygotes, the most widespread severe form was the neurological form with a frequency of 63.2%, the anemic form 26.3% and parasitic at 10.5%. In homozygous SS subjects, the most widespread severe form was the anemic form with a frequency of 68.1% followed by neurological forms 27.7% and parasitic forms 4.2%. Abdominal pain, prostration, respiratory distress were the main signs in SS homozygotes. In heterozygotes, prostration, convulsion and clinical jaundice were the main signs. A total of 99.8% of our patients were cured. Conclusions: All the electrophoretic profiles identified were subject to this infection which mainly affects heterozygous AS subjects and subjects with the AA electrophoretic profile in its severe neurological form and homozygous SS subjects in its anemic form.

From parents to children: associations of traffic risks with impulsivity, family relationships and serotonin transporter genotype.

Road traffic injuries are the leading cause of death for young adults, and parents play a major role in shaping their traffic behaviour. Higher impulsivity (predictor of higher traffic risk) has been shown to be dependent on family relations and the serotonin transporter gene promoter polymorphism (5-HTTLPR). The specific mechanisms for the inheritance of risky traffic behaviour from parents to children are not clear, and the genetic aspect has not been studied before. We used data of Estonian Children Personality Behaviour and Health Study subjects (n = 596, mean age = 25.2 ± 0.6) and their parents (mothers, n = 460, mean age = 52.1 ± 5.8; fathers, n = 339, mean age = 54.1 ± 6.5). Family relationships scale, traffic risk questionnaires and Adaptive and Maladaptive Impulsivity Scale were filled out. The increased risk-taking behaviour of parents and worse quality of family relationship were significant predictors of higher traffic risk among subjects. Family support and impulsivity of fathers significantly predicted the subjects' traffic risk score in interaction with 5-HTTLPR genotype: l'/l' homozygous subjects with adaptively impulsive fathers had higher traffic risk, whereas for s'-allele carrying subjects family support was more significant. Parental role modelling and family relationships are significant predictors of future traffic behaviour of the child. Whether the behavioural example of the father or the influence of family relationships is more important in predicting future risky traffic behaviour, depends on the 5-HTTLPR genotype of the child.

Effect of the rs2821557 Polymorphism of the Human Kv1.3 Gene on Olfactory Function and BMI in Different Age Groups.

The sense of smell plays an important role in influencing the eating habits of individuals and consequently, their body weight, and its impairment has been associated with modified eating behaviors and malnutrition problems. The inter-individual variability of olfactory function depends on several factors, including genetic and physiological ones. In this study, we evaluated the role of the Kv1.3 channel genotype and age, as well as their mutual relationships, on the olfactory function and BMI of individuals divided into young, adult and elderly groups. We assessed olfactory performance in 112 healthy individuals (young n = 39, adult n = 36, elderly n = 37) based on their TDI olfactory score obtained through the Sniffin' Sticks test and their BMI. Participants were genotyped for the rs2821557 polymorphism of the human gene encoding Kv1.3 channels, the minor C allele of which was associated with a decreased sense of smell and higher BMIs compared to the major T allele. The results show that TT homozygous subjects obtained higher TDI olfactory scores and showed lower BMIs than CC homozygous subjects, in all age groups considered. Furthermore, the positive effect of the T allele on olfactory function and BMI decreased with increasing age. The contribution of the genetic factor is less evident with advancing age, while the importance of the age factor is compensated for by genetics. These results show that genetic and physiological factors such as age act to balance each other.

Clinical efficacy of CFTR modulator therapy in people with cystic fibrosis carrying the I1234V mutation

BackgroundThe cystic fibrosis transmembrane conductance regulator (CFTR) mutation I1234V (I1234V, p.Ile1234Val, c.3700A>G), is a missense-mutation that creates a cryptic splice site, with the formation of a protein lacking 6 amino acids, that is misfolded and misprocessed. The in vitro effects of CFTR modulator (CFTRm) therapies on human bronchial cell models and intestinal organoids carrying this mutation are conflicting. The aim of this study was therefore to explore the clinical efficacy of CFTRm in people with cystic fibrosis (pwCF) carrying this mutation. MethodsThis was a retrospective descriptive study of the clinical records of homozygous and compound heterozygous (none F508del) pwCF, for the I1234V mutation, that received CFTRm. Parameters explored were body mass index (BMI), forced expiratory volume in one second percent predicted (FEV1%), lung clearance index (LCI) and quantitative sweat chloride measurements. ResultsMean age was 38.6 ± 14 years (range 21–60). Two subjects were homozygous and five compound heterozygous, with minimal function mutations. Four were pancreatic insufficient and three pancreatic sufficient. The two homozygous subjects received Tezacaftor/Ivacaftor, the remaining Elexacaftor/Tezacaftor/Ivacaftor (ETI); treatment ranged from 6 to 12 months. Mean BMI score increased from 21.7 ± 1.3 to 23.6 ± 2.1 kg/m2 (p = 0.04); FEV1(%pred) increased by 20.14±10.2while mean change in FEV1 in the year prior to CFTRm initiation was -0.14±1.18 (p = 0.0001). Additionally, LCI 2.5% decreased from 18.7 to 14.5 (p = 0.07); sweat chloride decreased from 116±10 to 90±17 mEq/L (p = 0.017) and chronic pseudomonas airway infection was eradicated in one subject. ConclusionsThis study supports a clinical benefit for CFTRm therapy in pwCF carrying the I1234V mutation.

When to suspect infantile hypercalcemia-1?

The screening test to suspect infantile hypercalcemia-1 (HCINF1) is the measure of 25(OH)D3/24,25(OH)2D3 ratio at mass spectroscopy (MS). When the ratio is > 80, the gold standard for the diagnosis is genetic analysis. Given its limited availability, MS may not represent a screening test and most cases of HCINF1 remain undiagnosed. Aim of the study is to identify cut-offs of serum calcium and PTH useful to suspect patients with HCINF1. We compared the levels of total serum calcium and PTH of 6 patients with HCINF1 harboring biallelic CYP24A1 pathogenic variants with 3 different control groups: (1) 12 subjects wild type for CYP24A1; (2) 12 subjects matched for age and sex; (3) 12 subjects matched for vitamin D levels. We validated the cut-offs, testing the number of adult patients affected by HCINF1 reported in the literature that could be identified using these cut-offs. A serum calcium level > 9.6mg/dL showed the highest sensitivity (100%) and specificity (91%) in the comparison between homozygous and wild-type subjects. A serum PTH index < 0.315 showed the highest sensitivity (100%) and specificity (83.3%). A serum calcium level > 9.6mg/dL was able to identify all adult HCINF1 patients whereas a PTH ratio < 0.315 identified 89.8% of the cases. Superimposable results were obtained using the other control groups. Patients with serum calcium levels higher than 9.6mg/dL and a PTH index lower than 0.315 are likely to be affected by HCINF1. Their diagnosis may be confirmed using MS and genetic analysis.

GNE myopathy: can homozygous asymptomatic subjects give a clue for the identification of protective factors?

GNE myopathy is caused by bi allelic recessive mutations in the GNE gene. The largest identified cohort of GNE myopathy patients carries a homozygous mutation- M743T (the “Middle Eastern” mutation). More than 160 such patients in 67 families have been identified by us. Mean onset in this cohort is 30 years (range 17–48) with variable disease severity. However, we have identified two asymptomatic females, homozygous for M743T in two different families, both with affected siblings. The first showed no myopathy when examined at age 76 years. The second has no sign of disease at age 60 years. Since both agreed only for testing of blood, we performed exome and RNA sequencing of their blood and that of their affected siblings. Various filtering layers resulted in 2723 variant loci between symptomatic and asymptomatic individuals, representing 1364 genes. Among those, 39 genes are known to be involved in neuromuscular diseases, and only in two of them the variant is located in the proper exon coding region, resulting in a missense change. Surprisingly, only 27 genes were significantly differentially expressed between the asymptomatic and the GNE myopathy affected individuals, with three overexpressed genes overlapping between exome and RNA sequencing. Although unable to unravel robust candidate genes, mostly because of the very low number of asymptomatic individuals analyzed, and because of the tissue analyzed (blood and not muscle), this study resulted in relatively restricted potential candidate protective genes, emphasizing the power of using polarized phenotypes (completely asymptomatic vs clearly affected individuals) with the same genotype to unmask those genes which could be used as targets for disease course modifiers.

Comparative effects of CFTR modulators on phagocytic, metabolic and inflammatory profiles of CF and nonCF macrophages

Macrophage dysfunction has been well-described in Cystic Fibrosis (CF) and may contribute to bacterial persistence in the lung. Whether CF macrophage dysfunction is related directly to Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) in macrophages or an indirect consequence of chronic inflammation and mucostasis is a subject of ongoing debate. CFTR modulators that restore CFTR function in epithelial cells improve global CF monocyte inflammatory responses but their direct effects on macrophages are less well understood. To address this knowledge gap, we measured phagocytosis, metabolism, and cytokine expression in response to a classical CF pathogen, Pseudomonas aeruginosa in monocyte-derived macrophages (MDM) isolated from CF F508del homozygous subjects and nonCF controls. Unexpectedly, we found that CFTR modulators enhanced phagocytosis in both CF and nonCF cohorts. CFTR triple modulators also inhibited MDM mitochondrial function, consistent with MDM activation. In contrast to studies in humans where CFTR modulators decreased serum inflammatory cytokine levels, modulators did not alter cytokine secretion in our system. Our studies therefore suggest modulator induced metabolic effects may promote bacterial clearance in both CF and nonCF monocyte-derived macrophages.

Modeled Impact of APOE4 Genotype on ARIA‐E Incidence in Patients Treated With Lecanemab

AbstractBackgroundLecanemab is a humanized IgG1 monoclonal antibody that preferentially targets soluble aggregated Aβ species with activity at insoluble fibrils. A multicenter, double‐blind, placebo‐controlled phase 2 study (Study 201 Core) was conducted in 856 patients with early Alzheimer’s disease (EAD). Patients could optionally participate in an open label extension (OLE) study at a dose of 10 mg/kg bi‐weekly (Q2W). Amyloid related imaging abnormalities — edema/effusion (ARIA‐E) was a main adverse event of special interest. Incidence of ARIA‐E was lecanemab dose‐dependent and greater in APOE4 carriers. A previously presented logistic model found steady‐state Cmax was a predictor of ARIA‐E incidence and more likely in APOE4 carriers (Hussein, 2019).MethodsThis work expands upon the previously developed logistic model by exploring the effect of APOE4 genotype (noncarrier, heterozygous carrier, homozygous carrier) on ARIA‐E incidence. Modeling was conducted using NONMEM 7.4.3 with data from Study 201 Core. Model predictions were compared to the observed incidence in the OLE study among patients newly treated with lecanemab (ie, placebo‐treated in the Core study).ResultsInclusion of APOE4 genotype as a covariate in the model with three categories (noncarrier, heterozygous carrier, homozygous carrier) led to a statistically significant decrease in model objective function (p &lt;0.001). A model utilizing only 2 categories (homozygous carrier, others) was not significantly different from the model with 3 categories (p = 0.5297). Model‐predicted ARIA‐E rates for APOE4 homozygous carriers treated with lecanemab 10 mg/kg Q2W were 22.5% (versus 6.8% in heterozygous or 5.4% in noncarriers) and comparable to the observed 25% incidence in newly‐treated homozygous carriers (1/4) in the OLE study, and less than the 50% incidence in homozygous carriers (5/10) in the Core.ConclusionsThe incidence of ARIA‐E in subjects treated with lecanemab appears highest in APOE4 homozygous subjects. No statistically significant difference in ARIA‐E incidence was found between non‐carriers and heterozygous carriers. Data from the larger CLARITY‐AD study will be needed to confirm these findings.Reference: Hussein, et al., Population Pharmacokinetic (PK) and Exposure‐Response (ER) Analyses for Efficacy and Safety of BAN2401 in Patients with Early Alzheimer’s Disease (AD), International Conference on Alzheimer’s &amp; Parkinson’s Diseases (AD/PD), 2019.

Modelling the impact of protein-kinase R allelic variant on HIV biomarkers trajectories by means of latent class mixed models

This paper is based on a retrospective longitudinal study on people living with HIV under antiretroviral treatment (ART) where allelic variants (either heterozygous CT genotype or homozygous CC genotype) have been evaluated at position −168 of the promoter region of the protein kinase R (−168/PKR). In general, antiviral effects of interferon are partially mediated by a RNA-dependent protein kinase (PKR) that, once activated, inhibits protein synthesis. Indeed, activation of PKR response can inhibit HIV replication. To explore the role of allelic variants in shaping dynamics of commonly monitored HIV biomarkers, CD4 cells, CD8 cells and HIV-load were modelled within a latent class mixed model (LCMM) to account for participants’ heterogeneity over time. The estimated models identified two sub-groups from CD4 and HIV-load dynamics, revealing better outcomes for subgroups of participants with the heterozygous CT genotype. Heterozygous CT subjects in one of the two identified subgroups exhibited higher increase of CD4 cells and more marked decrease of HIV-load, over time, with respect to the homozygous CC subjects assigned to the same group.

The PINK1 p.Asn521Thr Variant Is Associated with Earlier Disease Onset in GRN/C9orf72 Frontotemporal Lobar Degeneration.

Genetic frontotemporal lobar degeneration (FTLD) is characterized by heterogeneous phenotypic expression, with a disease onset highly variable even in patients carrying the same mutation. Herein we investigated if variants in lysosomal genes modulate the age of onset both in FTLD due to GRN null mutations and C9orf72 expansion. In a total of 127 subjects (n = 74 GRN mutations and n = 53 C9orf72 expansion carriers), we performed targeted sequencing of the top 98 genes belonging to the lysosomal pathway, selected based on their high expression in multiple brain regions. We described an earlier disease onset in GRN/C9orf72 pedigrees in subjects carrying the p.Asn521Thr variant (rs1043424) in PTEN-induced kinase 1 (PINK1), a gene that is already known to be involved in neurodegenerative diseases. We found that: (i) the PINK1 rs1043424 C allele is significantly associated with the age of onset; (ii) every risk C allele increases hazard by 2.11%; (iii) the estimated median age of onset in homozygous risk allele carriers is 10-12 years earlier than heterozygous/wild type homozygous subjects. A replication study in GRN/C9orf72 negative FTLD patients confirmed that the rs1043424 C allele was associated with earlier disease onset (-5.5 years in CC versus A carriers). Understanding the potential mechanisms behind the observed modulating effect of the PINK1 gene in FTLD might prove critical for identifying biomarkers and/or designing drugs to modify the age of onset, especially in GRN/C9orf72-driven disease.

Nasal Nitric Oxide Levels: Improving the Diagnosis of Primary Ciliary Dyskinesia in Puerto Rico.

Primary Ciliary Dyskinesia (PCD) is a rare genetic disease characterized by motile cilia dysfunction with a prevalence of 1 in 16,309 individuals in Hispanic populations. In Puerto Rico, the prevalence of PCD is unknown. Diagnosis of PCD in Puerto Rico is challenging due to the lack of diagnostic technology. Algorithms for PCD diagnosis include clinical history, genetic testing, ciliary biopsy, and nasal Nitric Oxide (nNO) levels. For the first time, this study successfully implemented and measured the nNO levels in subjects with the RSPH4A (c.921+3_921+6del (intronic)) as a diagnostic tool to complement the current algorithm for PCD diagnosis on the island. The nNO level differentiated homozygous subjects with PCD due to the RSPH4A (c.921+3_921+6del (intronic)) founder mutation compared to healthy gender-age matched controls and subjects with VUS or negative genetic testing for PCD. The acquisition of state-of-the-art diagnostic tools such as nNO positively impacted and expanded our current PCD diagnostic capabilities in Puerto Rico for our founder genetic mutation. The addition of nNO technology promotes earlier disease screening and recognition for patients with PCD on the island. The access to nNO helped us to properly characterize the PCD diagnosis for patients with the RSPH4A (c.921+3_921+6del (intronic)). As a result, our findings will allow us to be part of the national PCD foundation registry and represent Puerto Rican Hispanics in future PCD multicentric clinical trials.

Genetic analysis of the aquaporin water channels AQP12A and AQP12B in patients with chronic pancreatitis

BackgroundAlterations in genes specifically expressed in the pancreas have been associated with chronic pancreatitis (CP). A significant percentage of patients with non-alcoholic CP, however, do not have mutations in known risk genes, suggesting the existence of further susceptibility genes. Four aquaporins are expressed in the exocrine pancreas: AQP1, AQP5, AQP8 and AQP12, the latter being found exclusively in this organ. Therefore, we investigated the two AQP12 genes, AQP12A and AQP12B, in CP patients. MethodsWe analyzed all exons and adjacent intronic regions of AQP12A and AQP12B in 292 German patients with non-alcoholic CP and 143 control subjects by direct DNA sequencing. ResultsIn total, we discovered 41 non-synonymous changes, three of which were nonsense variants. Genotype and allele frequencies of these variants did not differ significantly between patients and controls (all p-values >0.05). Remarkably, we found a common nonsense variant in AQP12B, p.S152Tfs∗24, with an allele frequency of 15.7% in controls, including 2.8% homozygous subjects. This finding suggests that AQP12B is physiologically dispensable for normal pancreatic function. ConclusionsOur results suggest that genetic alterations in AQP12A and AQP12B do not predispose to the development of non-alcoholic CP.

Fetal hemoglobin regulating genetic variants identified in homozygous (HbSS) and heterozygous (HbSA) subjects from South Mexico.

Hemoglobin S is caused by a nucleotide change in HBB gene (HBB:c.20A&gt;T, p.Glu6Val), is presented in diverse forms: simple carriers (HbSA), homozygotes (HbSS) also known as sickle cell anemia, and compound heterozygotes with other β-hemoglobinopathies. It is worldwide distributed, in Mexico, is frequently observed in the southern states Guerrero, Oaxaca and Chiapas. Elevated fetal hemoglobin (HbF) is associated with mild phenotype; single-nucleotide variants (SNVs) in modifier genes, such as BCL11A, HBG2, HBBP1 pseudogene and HBS1L-MYB intergenic region, upregulate HbF synthesis. The aim of this study was to identify HbF regulating genetic variants in HbSS and HbSA Mexican subjects. We studied 39 individuals (HbSS = 24, 61%, HbSA = 15, 39%) from Chiapas (67%) and Guerrero (33%), peripheral blood was collected in ethylenediamine tetraacetic acid (EDTA) for molecular and hematological studies, DNA was isolated by salting-out technic and genotyping was performed through allelic discrimination by real time polymerase chain reaction (RT-PCR) using Taqman® probes for 15 SNV (in BCL11A: rs6706648, rs7557939, rs4671393, rs11886868, rs766432, rs7599488, rs1427407; HBS1L-MYB: rs28384513, rs7776054, rs9399137, rs4895441, rs9402686, rs1320963; HBG2: rs7482144; and HBBP1: rs10128556). The obtained data were analyzed using IMB SPSS v.22.0 software. All minor alleles were observed in frequencies over 0.05, the most frequent was rs9402686 (0.82), while the less frequent was rs101028556 (0.08). In HbSS group, the mean fetal hemoglobin was 11.9 ± 5.9% and was significantly elevated in BCL11A rs11886868 wildtype homozygotes and in carriers of HBS1L-MYB intergenic region rs7776054 (p = 0.04 and p = 0.03, respectively). In conclusion, in HbSS Mexican patients, two SNVs were observed related to increased HbF; BCL11A rs11886868 and HBS1L-MYB rs7776054.

Cognitive Function in Cystic Fibrosis and CFTR Modulator Therapy

Background: Cystic fibrosis is not typically associated with cognitive dysfunction that is easily discernible. Whether having a CFTR mutation has a direct effect on the CNS function is yet to be elucidated, despite widespread expression of the CFTR protein throughout the human nervous system. Methods: We aimed to study the effects of CFTR modulators ivacaftor and lumacaftor/ivacaftor on cognition in two separate CF cohorts. These were ivacaftor, in CF patients with at least one copy of the G551D mutation, and lumacaftor/ivacaftor in homozygous F508del subjects. Using a panel of cognitive testing tools (MOCA, TMT, Cogstate™) targeting various domains that included executive function, memory and attention. Results: The two cohorts improved significantly on CFTR modulator treatment when measured by the MOCA, TMT and by a combined cognitive score. Most prominently, these represent improvements in executive function. Conclusion: Suggested CNS effect of CFTR mutation in CF and the impact of CFTR modulators on this.

Whole blood samples for faster real-time PCR analysis of thrombophilic mutations in SARS-CoV-2 virus positive patients.

High incidence of thrombosis and venous thromboembolism was reported in patients with COVID-19. In this study, we focused on analysis of thrombophilic mutations performed without a standard DNA extraction step. In one hundred of COVID-19 positive outpatients, real-time PCR for Leiden mutation in the FV gene and G20210A mutation in the FII gene was carried out from DNA extracts and modified whole blood samples, and their cycle threshold (Ct) values were evaluated. In the extracts, healthy homozygotes (wt/wt), heterozygotes (M/wt), and homozygous carriers of Leiden mutation (M/M) provided median Ct values of 18.5, 19.4/22.0, and 20.9. In the whole blood, Ct values were 25.3 (wt/wt), 24.8/27.2 (M/wt), and 26.9 (M/M). Median Ct values for G20210A in the extracts were 19.6 for homozygotes (wt/wt), and 19.7/20.4 for heterozygous carriers. The whole blood samples provided Ct values of 23.9 in healthy homozygotes and 26.3/27.2 in heterozygotes for G20210A mutation. No homozygous subjects for G20210A and no double heterozygotes (for Leiden and G20210A mutations) were found. Despite significant differences in the Ct values, genotyping showed complete result concordance of the DNA extracts and the whole blood samples. The integrity and amplificability of DNA molecules in the whole blood samples during 28 days of deep freezing, interrupted by four cycles of thawing, did not significantly change. In conclusion, we demonstrated a new protocol for the detection of the thrombophilic mutations via real time PCR on the modified whole blood of COVID-19 positive patients. The blood modification was reliable, easy, cheap, and saving costs and turnaround time of the whole laboratory process.

Genome‐Wide Association Study for the Genetic Determinants of Thiopurine S‐Methyltransferase Protein Expression in the Liver

HypothesisSinge nucleotide polymorphisms will be associated with differential expression of Thiopurine S‐Methyltransferase (TPMT) in the liver.MethodsNormal human liver samples (n=288) were acquired from University of Minnesota Liver Tissue Cell Distribution System, the Cooperative Human Tissue Network, and XenoTech LCC (Lenexa, KS, USA). Absolute quantification of TPMT in liver microsomes was calculated using a DIA total protein approach (DIA‐TPA). Human liver samples were genotyped using the Illumina Multi‐Ethnic Global Assay (Illumina, Miami, USA).ResultsAfter accounting for population stratification, genome‐wide association study (GWAS) analysis was conducted on 243 human liver samples. There were 30 genetic variants, all located on chromosome 6, that passed our genome‐wide threshold (P &lt; 5.0 x 10‐8) after Bonferroni correction. Further GWAS analysis conditioning on rs1142345 (TPMT*3C/TPMT*3A), the strongest signal within the dataset and a known nonfunctional TPMT allele, showed no other independent signals. The presumed homozygous wild‐type TPMT subjects had a 1.97‐fold higher expression of TPMT than the TPMT*3A heterozygotes (0.1056 pmol/mg ± 0.0289 pmol/mg vs. 0.0536 pmol/mg ± 0.0143 pmol/mg, p‐value: 8.4e‐14).When comparing TPMT expression by ancestry, European ancestry donors (n= 214) had significantly higher expression than African ancestry donors (n= 34) when removing TPMT*3A carriers (0.1085 pmol/mg ± 0.0260 pmol/mg vs. 0.0860 pmol/mg ± 0.0416 pmol/mg, p‐value: 0.004.ConclusionFor the first time, we quantified absolute TPMT protein expression in the liver using a liquid chromatography tandem mass spectrometry based DIA‐TPA proteomics approach and conducted a GWAS to identify genetic variants affecting hepatic TPMT protein expression. The only independent genetic signal from the GWAS was from the TPMT*3A haplotype, which is comprised of two nonsynonymous SNPs rs1800460 and rs1142345. Previous in vitrostudies investigating the effect of common polymorphisms on TPMT expression in COS‐1 cells demonstrated that TPMT*3A is almost a complete loss of detectable TPMT due to its rapid degradation rate.1 This is in line with our expression data, where heterozygous carriers of TPMT*3A had about half the amount of TPMT as wild‐type subjects.We also discovered that donors with African ancestry had significantly less TPMT expression than donors with European ancestry after removing samples that had known TPMT polymorphisms (TPMT*3A/*3B/*3C). A previous study reported patients of Afro‐Caribbean ancestry had significantly lower TPMT activity than those of European or South Asian descent.2 Future studies need to be conducted to determine if the difference in TPMT expression by ancestry is due to genetic polymorphisms or other factors.

Clinical presentation of major sickle cell syndrome in children under 5 years at Kindu hospital environment, Democratic Republic of Congo (DRC)

Sickle cell disease is the most common genetic disorder of hemoglobin in the world today. Screening is the basis of any program aimed at its fight. Faced with the difficulties of implementing screening in countries with limited resources, it is important to resort to alternative strategies, in particular the optimization of clinical suspicion. This study was conducted with the objective of presenting the clinical characteristics of SS sickle cell disease revealed by laboratory screening in pediatric hospitals. A cross-sectional, descriptive study with prospective collection was carried out in 5 health facilities in the city of Kindu in the DRC between December 2, 2019 to October 15, 2020. Our results show that the hospital prevalence of major sickle cell syndrome was 12.7% in the study population. Boys accounted for 53% of cases. The most represented age group was 48 to 59 months with 56.1%. On the clinical level, the examination of our respondents objectified a malnutrition in 36.8% of cases, the presence of frontal bumps in 10.5% of cases, lymphadenopathy in 10.5% of cases, hypertrophy of the tonsils. in 8.8% of cases, conjunctival jaundice in 35.1% of cases, hepatomegaly in 7.0% of cases and splenomegaly in 21.1% of cases. There are significant associations between certain epidemiological characteristics studied in homozygous SS subjects, in particular the age of 48 to 59 months with jaundice (p = 0.012) and splenomegaly (p = 0.028), undernutrition with jaundice (p = 0.037) and the presence of lymphadenopathy (p = 0.013), presence of frontal lumps with enlarged tonsils (p = 0.0001) and hepatomegaly (p = 0.008), splenomegaly with jaundice (p = 0.001) and presence of lymphadenopathy (p = 0.004) and finally hepatomegaly and the presence of lymphadenopathy (p = 0.008). In short, it emerges that many children with major sickle cell syndrome have a less expressive clinical presentation. This is probably linked to the fact that at this age they still have a level of hemoglobin F sufficient to attenuate the impact of hemoglobin S. The associations observed between various clinical parameters show that it is possible to develop a clinic score that can guide the suspicion of the disease and motivate a biological screening.

Steady-state indirect bilirubin level in sickle cell anemia: A comparative hospital-based cross-sectional study

Background: The major forms of sickle cell disease are characterized by hemolysis. The extent of this hemolysis may itself depend on the form of the disease even in the steady-state. This study aims to compare the indirect bilirubin level between the homozygous and beta plus sickle cell anemia (SAFA2) in the steady-state conditions. Material and methods: Fifty subjects of each forms, homozygous and beta plus sickle cell anemia were enrolled in a comparative hospital-based cross-sectional study from April 2008 to May 2008 at the laboratory of the university hospital of Yopougon, Ivory Coast. Subjects of each form awaiting their visits were selected from the database of the patients regularly followed in the clinical hematology department of Yopougon University Hospital. During their visits, clinical and socio-demographic data were collected, and a blood sample was also taken to carry out biological examinations. Blood count and bilirubin testing were performed by using Sysmex Kx-21™ and BioMérieux KONELAB-20™, respectively. Data were analysis in the software Statistical Product and Service Solutions version 12.0. Shapiro test was used to verify data normality and Student t-test for the comparison of parametric data means or Mann-Whitney’s independent test for none-parametric data. Pearson Chi square tests or Yate’s correction test for continuity where the first test was not appropriate. The threshold of statistical significance was set at p ≤ 0.05. Results: The median Hb was higher in SAFA2 patients compared to homozygous SSFA2 patients 10.7 g/dL [IQR = 8] vs 7.3 g/dL [IQR = 7]; p &lt; 0.001. In contrast, the median of indirect bilirubin was lower in SAFA2 patients compared to SSFA2 patients 5.6 μmol/L [IQR = 10] vs 15.1 μmol/L [IQR = 13], p &lt; 0.001. The ratio of these two medians shows that subjects SAFA2 hemolysis 2.7 times less than the homozygous subjects SSFA2 in the steady-state. Out of the one hundred subjects, indirect hyperbilirubinemia defined as indirect bilirubin median &gt; 14 μmol/L was higher in men than in women 79.2% vs 20.8%, p = 0.01 whereas patients age groups was not associated to indirect hyperbilirubinemia, p = 0.4. Conclusion: Our data suggest that the hemolysis is higher in subjects SSFA2 than SAFA2 subjects in the steady-state. This marked chronic hemolysis of SSFA2 subjects must be taken into account when it comes to give a comprehensive care to these subjects.

A polymorphism in the human gene encoding OBPIIa affects the perceived intensity of smelled odors

Among the factors that contribute to the physiological variability of the olfactory function of individuals, an important role seems to be played by the OBPs present in the mucus that bathes the ciliated terminals of the olfactory sensory neurons, facilitating the access of odorants to the olfactory receptors. It was recently highlighted that the rs2590498 polymorphism in the odor binding-protein (OBPIIa) gene it is associated with the olfactory threshold in healthy individuals. Aim of this study was to evaluate: 1) the presence of a relationship between the threshold olfactory performance of healthy subjects and the intensity with which they perceive the smelled odorants, and 2) the effect of the rs2590498 polymorphism of the OBPIIa gene on perceived intensity. We found a positive correlation between threshold olfactory and perceived intensity, and that AA homozygous subjects reported a perceived intensity higher than heterozygous and GG homozygous subjects. By showing a positive effect of the rs2590498 polymorphism of the hOBPIIa gene on the intensity perceived, these results suggest that it allows a larger number of molecules in an odorous mixture to reach the olfactory receptors.

Common ABCB1 SNP, C3435T could affect systemic exposure of dapagliflozin in healthy subject.

P-glycoprotein (P-gp) is a transporter that plays an excretory role in epithelial cells. It is encoded by ABCB1, and single nucleotide polymorphisms (SNPs) in this gene can affect systemic drug exposure. Dapagliflozin and sitagliptin, used in type 2 diabetes treatment, are P-gp substrates. Here, we aimed to investigate whether ABCB1 polymorphisms affect dapagliflozin and sitagliptin pharmacokinetics (PK) in healthy Korean subjects. The study population consisted of 100 healthy Korean subjects (94 men and 6 women) who participated in four different clinical trials and received dapagliflozin and sitagliptin doses of 10 and 100 mg, respectively. We determined ABCB1 genotypes for the C3435T, C1236T, and G2677T/A SNPs. The relationship between the genotypes and dapagliflozin PKs was examined. Dapagliflozin and sitagliptin PK parameters were not statistically significantly affected by ABCB1 SNP genotypes. However, homozygous 3435TT subjects showed higher dapagliflozin PK parameters than CT and CC subjects. In subjects with the 3435TT and those with 3435CC and 3435CT genotypes, mean Cmax, AUCinf, and AUC0-1 values of dapagliflozin were 223.06 ng/mL and 194.81 ng /mL (p = 0.2767), 673.58 ng*h/mL and 573.96 ng*h/mL (p = 0.0492), and 128.53 ng*h/mL and 104.61 ng*h/mL (p = 0.2678), respectively. In summary, dapagliflozin and sitagliptin PK parameters were not significantly different between individuals with C1236T and C2677T/A ABCB1 genetic polymorphisms. Dapagliflozin exhibited higher systemic exposure in 3435TT subjects than in CC/CT subjects.