Kinetics of glucose-6-phosphate dehydrogenase (G6PD) activity during Plasmodium vivax infection: implications for early radical malaria treatment.

BACKGROUND: Plasmodium vivax relapses due to dormant liver hypnozoites can be prevented with primaquine. However, the dose must be adjusted in individuals with glucose-6-phosphate-dehydrogenase (G6PD) deficiency. In French Guiana, assessment of G6PD activity is typically delayed until day (D)14 to avoid the risk if misclassification. This study assessed the kinetics of G6PD activity throughout P. vivax infection to inform the timing of treatment. METHODS: For this retrospective monocentric study, data on G6PD activity between D1 and D28 after treatment initiation with chloroquine or artemisinin-based combination therapy were collected for patients followed at Cayenne Hospital, French Guiana, between January 2018 and December 2020. Patients were divided into three groups based on the number of available G6PD activity assessments: (i) at least two measurements during the P. vivax malaria infection; (ii) two measurements: one during the current infection and one previously; (iii) only one measurement during the malaria infection. RESULTS: In total, 210 patients were included (80, 20 and 110 in groups 1, 2 and 3, respectively). Data from group 1 showed that G6PD activity remained stable in each patient over time (D1, D3, D7, D14, D21, D28). None of the patients with normal G6PD activity during the initial phase (D1-D3) of the malaria episode (n = 44) was categorized as G6PD-deficient at D14. Patients with G6PD activity < 80% at D1 or D3 showed normal activity at D14. Sex and reticulocyte count were statistically associated with G6PD activity variation. In the whole sample (n = 210), no patient had severe G6PD deficiency (< 10%) and only three between 10 and 30%, giving a G6PD deficiency prevalence of 1.4%. Among the 100 patients from group 1 and 2, 30 patients (26.5%) were lost to follow-up before primaquine initiation. CONCLUSIONS: In patients treated for P. vivax infection, G6PD activity did not vary over time. Therefore, G6PD activity on D1 instead of D14 could be used for primaquine dose-adjustment. This could allow earlier radical treatment with primaquine, that could have a public health impact by decreasing early recurrences and patients lost to follow-up before primaquine initiation. This hypothesis needs to be confirmed in larger prospective studies.

Newborn screening in Colombia: The experience of a private program in Bogotá / Tamizaje neonatal en Colombia: la experiencia de un programa privado en Bogotá.

Introduction. The first neonatal screening program in Colombia ­ PREGEN ­ was set up in the medical private sector of Bogotá in 1988. We report the results from recent years that, given the scarcity of similar information in our country, may help estimate the frequency of the evaluated neonatal disorders and which ones should be included in the neonatal screening programs in our country. Objective. To describe the results of PREGEN´s newborn screening program between 2006 and 2019. Materials and methods. We analyzed databases and other informative documents preserved in PREGEN from the 2006-2019 period. Results. One in every 164 newborns screened in our program had an abnormal hemoglobin variant, and one in every 194 carried some hemoglobin S variant. Glucose-6- phosphate dehydrogenase deficiency and congenital hypothyroidism are next as the more common disorders. Conclusions. Abnormal hemoglobin causes the most frequent monogenic disorder in the world. Glucose-6-phosphate dehydrogenase deficiency is the most common enzymopathy affecting nearly 400 million individuals worldwide. Since both disorders are more common in people of African descent and confer some resistance to malaria, we believe that screening for both disorders may be more relevant in the areas with African ancestry in our country.

Introducción. En Colombia, el primer programa de tamizaje neonatal, PREGEN, inició labores en el sector privado de Bogotá en 1988. En este artículo se presentan los resultados obtenidos en los últimos años, que, dada la carencia de estos estudios en el país, pueden servir para evaluar la frecuencia de aparición de los trastornos congénitos evaluados y estimar cuáles de ellos deben ser objeto de tamizaje neonatal a nivel nacional. Objetivos. Reportar los resultados del programa de tamizaje PREGEN entre el 2006 y el 2019. Materiales y métodos. Para este análisis se examinaron las bases de datos y otros documentos informativos de PREGEN para el periodo 2006-2019. Resultados. Uno de cada 164 recién nacidos tamizados en el programa PREGEN en Bogotá presentó una variante anormal de la hemoglobina y uno de cada 194 es portador de hemoglobina S. Los siguientes dos trastornos más frecuentes encontrados fueron la deficiencia de la enzima glucosa-6-fosfato deshidrogenasa (frecuencia 1:2.231) y el hipotiroidismo congénito (frecuencia 1:3.915). Conclusiones. Las hemoglobinopatías mostraron ser uno de los desórdenes monogénicos más comunes, seguidos por la deficiencia de glucosa-6-fosfato deshidrogenasa y el hipotiroidismo congénito. Se calcula que cerca de 400 millones de personas en el mundo están afectadas por la deficiencia de glucosa-6-fosfato deshidrogenasa, por lo cual es la enzimopatía más común en el mundo. Como ambos desórdenes son más frecuentes en poblaciones de origen africano y confieren algún grado de resistencia a la malaria, es de prever que su tamizaje debe ser de mayor importancia en las zonas con ancestros africanos en Colombia.

Functional effects of an African glucose-6-phosphate dehydrogenase (G6PD) polymorphism (Val68Met) on red blood cell hemolytic propensity and post-transfusion recovery.

BACKGROUND: Donor genetic variation is associated with red blood cell (RBC) storage integrity and post-transfusion recovery. Our previous large-scale genome-wide association study demonstrated that the African G6PD deficient A- variant (rs1050828, Val68Met) is associated with higher oxidative hemolysis after cold storage. Despite a high prevalence of X-linked G6PD mutation in African American population (>10%), blood donors are not routinely screened for G6PD status and its importance in transfusion medicine is relatively understudied. STUDY DESIGN AND METHODS: To further evaluate the functional effects of the G6PD A- mutation, we created a novel mouse model carrying this genetic variant using CRISPR-Cas9. We hypothesize that this humanized G6PD A- variant is associated with reduced G6PD activity with a consequent effect on RBC hemolytic propensity and post-transfusion recovery. RESULTS: G6PD A- RBCs had reduced G6PD protein with ~5% residual enzymatic activity. Significantly increased in vitro hemolysis induced by oxidative stressors was observed in fresh and stored G6PD A- RBCs, along with a lower GSH:GSSG ratio. However, no differences were observed in storage hemolysis, osmotic fragility, mechanical fragility, reticulocytes, and post-transfusion recovery. Interestingly, a 14% reduction of 24-h survival following irradiation was observed in G6PD A- RBCs compared to WT RBCs. Metabolomic assessment of stored G6PD A- RBCs revealed an impaired pentose phosphate pathway (PPP) with increased glycolytic flux, decreasing cellular antioxidant capacity. DISCUSSION: This novel mouse model of the common G6PD A- variant has impaired antioxidant capacity like humans and low G6PD activity may reduce survival of transfused RBCs when irradiation is performed.

Prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency in Gia Lai Province, Vietnam.

Glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) deficiency is one of the most common X-linked hereditary disorders worldwide. G6PD deficiency provides resistance against severe malaria, but paradoxically, G6PD deficiency is also a stumbling block in fighting against malaria. Primaquine (PQ), a drug for the radical cure of Plasmodium vivax, can cause lethal acute hemolytic anemia in malaria patients with inherited G6PD deficiency. In this study, we analyzed the phenotypic and genotypic G6PD deficiency status in 1721 individuals (963 males and 758 females) residing in three malaria-endemic areas within the Gia Lai province, Vietnam. The G6PD activity in individuals ranged from 3.04 to 47.82 U/g Hb, with the adjusted male median (AMM) of 7.89 U/g Hb. Based on the G6PD activity assay results, no phenotypic G6PD deficiency was detected. However, the multiplex polymerase chain reaction to detect G6PD variations in the gene level revealed that 26 individuals (7 males, 19 females) had Viangchan mutations (871 G > A). Sequencing analyses suggested that all the males were hemizygous Viangchan, whereas one was homozygous, and 18 were heterozygous Viangchan in females. These results suggested a relatively low prevalence of G6PD deficiency mutation rate (1.51%) in the minor ethnic populations residing in the Gia Lai province, Vietnam. However, considering these areas are high-risk malaria endemic, concern for proper and safe use of PQ as a radical cure of malaria is needed by combining a G6PD deficiency test before PQ prescription.

Radical cure for Plasmodium vivax malaria after G6PD qualitative testing in four provinces in Cambodia, results from Phase I implementation.

BACKGROUND: Cambodia aims to eliminate all forms of malaria by 2025. In 2020, 90% of all malaria cases were Plasmodium vivax. Thus, preventing P. vivax and relapse malaria is a top priority for elimination. 14-day primaquine, a World Health Organization-recommended radical cure treatment regimen, specifically targets dormant hypnozoites in the liver to prevent relapse. Cambodia introduced P. vivax radical cure with primaquine after glucose-6-phosphate dehydrogenase (G6PD) qualitative testing in 2019. This paper presents Cambodia's radical cure Phase I implementation results and assesses the safety, effectiveness, and feasibility of the programme prior to nationwide scale up. METHODS: Phase I implementation was carried out in 88 select health facilities (HFs) across four provinces. Males over 20kgs with confirmed P. vivax or mixed (P. vivax and Plasmodium falciparum) infections were enrolled. A descriptive analysis evaluated the following: successful referral to health facilities, G6PD testing results, and self-reported 14-day treatment adherence. P. vivax incidence was compared before and after radical cure rollout and a controlled interrupted time series analysis compared the estimated relapse rate between implementation and non-implementation provinces before and after radical cure. RESULTS: In the 4 provinces from November 2019 to December 2020, 3,239 P. vivax/mixed infections were reported, 1,282 patients underwent G6PD deficiency testing, and 959 patients received radical cure, achieving 29.6% radical cure coverage among all P. vivax/mixed cases and 98.8% coverage among G6PD normal patients. Among those who initiated radical cure, 747 patients (78%) completed treatment. Six patients reported side effects. In implementation provinces, an average 31.8 relapse cases per month were estimated signaling a 90% (286 cases) reduction in relapse compared to what would be expected if radical cure was not implemented. CONCLUSIONS: Plasmodium vivax radical cure is a crucial tool for malaria elimination in Cambodia. The high coverage of radical cure initiation and adherence among G6PD normal patients demonstrated the high feasibility of providing radical cure at point of care in Cambodia. Incomplete referral from community to HFs and limited capacity of HF staff to conduct G6PD testing in high burden areas led to lower coverage of G6PD testing. Phase I implementation informed approaches to improve referral completion and patient adherence during the nationwide expansion of radical cure in 2021.

Genetic analysis and molecular basis of G6PD deficiency among malaria patients in Thailand: implications for safe use of 8-aminoquinolines.

BACKGROUND: It was hypothesized that glucose-6-phosphate dehydrogenase (G6PD) deficiency confers a protective effect against malaria infection, however, safety concerns have been raised regarding haemolytic toxicity caused by radical cure with 8-aminoquinolines in G6PD-deficient individuals. Malaria elimination and control are also complicated by the high prevalence of G6PD deficiency in malaria-endemic areas. Hence, accurate identification of G6PD deficiency is required to identify those who are eligible for malaria treatment using 8-aminoquinolines. METHODS: The prevalence of G6PD deficiency among 408 Thai participants diagnosed with malaria by microscopy (71), and malaria-negative controls (337), was assessed using a phenotypic test based on water-soluble tetrazolium salts. High-resolution melting (HRM) curve analysis was developed from a previous study to enable the detection of 15 common missense, synonymous and intronic G6PD mutations in Asian populations. The identified mutations were subjected to biochemical and structural characterisation to understand the molecular mechanisms underlying enzyme deficiency. RESULTS: Based on phenotypic testing, the prevalence of G6PD deficiency (< 30% activity) was 6.13% (25/408) and intermediate deficiency (30-70% activity) was found in 15.20% (62/408) of participants. Several G6PD genotypes with newly discovered double missense variants were identified by HRM assays, including G6PD Gaohe + Viangchan, G6PD Valladolid + Viangchan and G6PD Canton + Viangchan. A significantly high frequency of synonymous (c.1311C>T) and intronic (c.1365-13T>C and c.486-34delT) mutations was detected with intermediate to normal enzyme activity. The double missense mutations were less catalytically active than their corresponding single missense mutations, resulting in severe enzyme deficiency. While the mutations had a minor effect on binding affinity, structural instability was a key contributor to the enzyme deficiency observed in G6PD-deficient individuals. CONCLUSIONS: With varying degrees of enzyme deficiency, G6PD genotyping can be used as a complement to phenotypic screening to identify those who are eligible for 8-aminoquinolines. The information gained from this study could be useful for management and treatment of malaria, as well as for the prevention of unanticipated reactions to certain medications and foods in the studied population.

G6PD gene detection in neonatal hyperbilirubinemia and analysis of related risk factors.

BACKGROUND: Hyperbilirubinemia is a common disorder in neonates, with premature infants at higher risk of developing the disorder. OBJECTIVE: Glucose-6-phosphate dehydrogenase (G6PD) gene detection was used to determine the incidence of G6PD deficiency and analyze the etiologies of G6PD deficiency in neonates with hyperbilirubinemia in the Zunyi region with the aim of providing scientific evidence for the clinical diagnosis and treatment. METHODS: For the gene detection, 64 neonates with hyperbilirubinemia were selected as the observation group and 30 normal neonates were selected as the control group, and the risk factors for hyperbilirubinemia were investigated by using multivariate logistic regression analysis. RESULTS: Among the neonates in the observation group, 59 cases had the G1388A mutation (92.19%) and 5 cases had the G1376T mutation (7.81%). No mutation was detected in the control group. In the observation group, the proportion of neonates who were born prematurely, with artificial feeding, with the age of starting feeding of more than 24 h, the time of first bowel movement of more than 24 h, premature rupture of membranes, infection, scalp hematoma, and perinatal asphyxia was higher than that in the control group, and the difference was statistically significant (p< 0.05). Multivariate logistic regression analysis showed that prematurity, infection, scalp hematoma, perinatal asphyxia, the age of starting feeding of more than 24 h, and the time of first bowel movement over 24 h were risk factors for the development of neonatal hyperbilirubinemia (p< 0.05). CONCLUSION: The G1338A and G1376T mutations were important features of the genetics of neonatal hyperbilirubinemia, and genetic detection together with the prevention of prematurity, infection, scalp hematoma, perinatal asphyxia, the age of starting feeding, and the time of first bowel movement would help reduce the incidence of this disease.

Glucose-6-phosphate dehydrogenase deficiency accelerates arterial aging in diabetes.

AIMS: High glucose levels and Glucose-6-Phosphate Dehydrogenase deficiency (G6PDd) have both tissue inflammatory effects. Here we determined whether G6PDd accelerates arterial aging (information linked stiffening) in diabetes. METHODS: Plasma glucose, interleukin 6 (IL6), and arterial stiffness (indexed as carotid-femoral Pulse Wave Velocity, PWV) and red blood cell G6PD activity were assessed in a large (4448) Sardinian population. RESULTS: Although high plasma glucose in diabetics, did not differ by G6DP status (178.2 ± 55.1 vs 169.0 ± 50.1 mg/dl) in G6DPd versus non-G6PDd subjects, respectively, IL6, and PWV (adjusted for age and glucose) were significantly increased in G6PDd vs non-G6PDd subjects (PWV, 8.0 ± 0.4 vs 7.2 ± 0.2 m/sec) and (IL6, 6.9 ± 5.0 vs 4.2 ± 3.0 pg/ml). In non-diabetics, neither fasting plasma glucose, nor IL6, nor PWV were impacted by G6PDd. CONCLUSION: G6PDd in diabetics is associated with increased inflammatory markers and accelerated arterial aging.

Glucose-6-phosphate dehydrogenase deficiency and psychotic disorders: A systematic review.

OBJECTIVES: Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD) is the most common enzymopathy globally. Early studies suggested an association with severe psychotic illness; however, changes to laboratory testing and diagnostic classification renders the association unclear. This study aims to explore the interaction between G6PD deficiency and psychotic symptoms, in particular to identify specific patterns of presentation or impact on outcomes. METHODS: Pubmed, Embase, and PsycInfo databases were searched from inception to May 2023. Descriptive statistics and narrative review of were used to synthesise data on demographics, mental and physical health diagnoses, investigations, treatment, and outcomes. RESULTS: No clear link was found in published data (eight case reports, case series of n = 29) with a high rate (63%) of haemolytic crisis at the time of psychiatric presentation suggested delirium as an alternative diagnosis. Four case control studies found no significant difference in the prevalence of G6PD deficiency. However, catatonic presentation was reported in 40% of the case series and a higher prevalence of G6PD deficiency in catatonic schizophrenia was noted in case control studies. CONCLUSIONS: Based on the information available there was no clear association between G6PD deficiency and psychotic illness or treatment resistance, although paucity of studies and risk of bias limit strong conclusions.

Screening results and mutation frequency analysis of G6PD deficiency in 1,291,274 newborns in Huizhou, China: a twenty-year experience.

OBJECTIVES: This study aimed to investigate the incidence rate and spectrum of gene mutations of Glucose-6-phosphate dehydrogenase (G6PD) deficiency in the Huizhou city of southern China to provide a scientific basis for disease prevention and control in the area. METHODS: From March 2003 to December 2022, newborn screening for G6PD enzyme activity was carried out in Huizhou city using the fluorescence quantitative method. Infants who tested positive during the initial screening were diagnosed using the nitroblue tetrazolium ratio method, while a subset of infants received further gene mutation analysis using the multicolor probe melting curve analysis method. RESULTS: A total of 1,291,274 newborns were screened and the screening rate has increased from 20.39% to almost 100%. In the 20-year period, 57,217 (4.43%) infants testing positive during the initial screening. Out of these infants, 49,779 (87%) were recalled for confirmatory testing. G6PD deficiency was confirmed in 39,261 of the recalled infants, indicating a positive predictive value of 78.87%. The estimated incidence rate of G6PD deficiency in the region was 3.49%, which was significantly higher than the average incidence rate of 2.1% in southern China. On the other hand, seven pathogenic G6PD variants were identified in the analysis of the 99 diagnosed infants with the most common being c.1388 G > A (48.5%), followed by c.95 A > G (19.2%), c.1376 G > T (15.2%), c.871 G > A (9.1%), c.1360 C > T (3.0%), c.392 G > T (3.0%), and c.487 G > A (1.0%). CONCLUSION: The incidence of G6PD deficiency in newborns in the Huizhou city was higher than the southern China average level, while the types and frequencies of gene mutations were found to vary slightly from other regions. Our findings suggested that free government screening and nearby diagnosis strategies could reduce the incidence of G6PD deficiency in the area.

The Association between Glucose 6-Phosphate Dehydrogenase Deficiency and Attention Deficit/Hyperactivity Disorder.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency, impacting 4.9% of the population and more prevalent in Mediterranean communities, is a common enzymopathy with potential relevance to Attention Deficit/Hyperactivity Disorder (ADHD). This study investigated this association. METHODS: The clinical characteristics of 7473 G6PD-deficient patients and 29,892 matched case-controls (selected at a 1:4 ratio) from a cohort of 1,031,354 within the Leumit Health Services database were analyzed using Fisher's exact test for categorical variables and the Mann-Whitney U test for continuous variables. RESULTS: In total, 68.7% were male. The mean duration of follow-up was 14.3 ± 6.2 years at a mean age of 29.2 ± 22.3 years. G6PD deficiency was associated with an increased risk of being diagnosed with ADHD (Odds Ratio (OR) = 1.16 [95% CI, 1.08-1.25], p < 0.001), seeking care from adult neurologists (OR = 1.30 [95% CI, 1.22-1.38], p < 0.001), and consulting adult psychiatrists (OR = 1.12 [95% CI, 1.01-1.24], p = 0.048). The use of stimulant medications among G6PD-deficient individuals was 17% higher for the methylphenidate class of drugs (OR = 1.17 [95% CI, 1.08, 1.27], p < 0.001), and there was a 16% elevated risk for amphetamine use (OR = 1.16 [95% CI, 1.03, 1.37], p = 0.047). CONCLUSIONS: G6PD deficiency signals an increased risk of ADHD diagnosis, more severe presentations of ADHD and a greater need for psychiatric medications to treat ADHD.

Prevalence and molecular heterogeneity of glucose-6-phosphate dehydrogenase (G6PD) deficiency in the Senoi Malaysian Orang Asli population.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked genetic disorder characterized by reduced G6PD enzyme levels in the blood. This condition is common in populations exposed to malaria; an acute febrile disease caused by Plasmodium parasites. G6PD-deficient individuals may suffer from acute hemolysis following the prescription of Primaquine, an antimalarial treatment. The population at risk for such a condition includes the Senoi group of Orang Asli, a remote indigenous community in Malaysia. This study aimed to elucidate the G6PD molecular heterogeneity in this subethnic group which is important for malaria elimination. A total of 662 blood samples (369 males and 293 females) from the Senoi subethnic group were screened for G6PD deficiency using a quantitative G6PD assay, OSMMR2000-D kit with Hb normalization. After excluding the family members, the overall prevalence of G6PD deficiency in the studied population was 15.2% (95% CI: 11-19%; 56 of 369), with males (30 of 172; 17.4%) outnumbering females (26 of 197; 13.2%). The adjusted male median (AMM), defined as 100% G6PD activity, was 11.8 IU/gHb. A total of 36 participants (9.6%; 26 male and 10 female) were deficient (<30% of AMM) and 20 participants (5.4%; 4 male and 16 female) were G6PD-intermediate (30-70% of AMM). A total of 87 samples were genotyped, of which 18 showed no mutation. Seven mutations were found among 69 genotyped samples; IVS11 T93C (47.1%; n = 41), rs1050757 (3'UTR +357A>G)(39.1%; n = 34), G6PD Viangchan (c.871G>A)(25.3%; n = 22), G6PD Union (c.1360C>T)(21.8%; n = 19), c.1311C>T(20.7%; n = 18), G6PD Kaiping (c.1388G>A)(8.0%; n = 7), and G6PD Coimbra (c.592C>T)(2.3%; n = 2). Our analysis revealed 27 hemizygote males, 18 heterozygote females, 7 homozygote females, and 2 compound heterozygote females. This study confirms the high prevalence of G6PD deficiency among the Senoi Malaysian Orang Asli, with a significant degree of molecular heterogeneity. More emphasis should be placed on screening for G6PD status and proper and safe use of Primaquine in the elimination of malaria among this indigenous population.

Prevalence and association of early onset severe hyperbilirubinemia in newborn in the East China region: Retrospective medical record analyses.

Research on the prevalence and association of hyperbilirubinemia is controversial because of different cultures, demographics, and clinical conditions. The etiology of hyperbilirubinemia is affected by the environment and other factors in the newborn. The World Health Organization recommended a 1-day hospital stay after uncomplicated delivery, jaundice assessment before discharge, and screening on 3rd and 7th days after birth for hyperbilirubinemia. However, the implementation of these recommendations is difficult in China. The objective of this study was to evaluate the prevalence and association of early onset severe hyperbilirubinemia in newborns in East China. Retrospective medical record analyses for 250 cesarean sections or vaginal deliveries, ≥2 kg body weight, and negative for Hepatitis B surface antigen by birth newborns were performed. A biochemical analyzer, quantitative assay, and quantitative polymerase chain reaction were used to evaluate total serum bilirubin, glucose-6-phosphate dehydrogenase (G6PD) deficiency, and gene variant phenotyping, respectively. A total in 33 (13%) newborns were reported with early onset severe hyperbilirubinemia (according to the American Academy of Pediatrics, total serum bilirubin ≥ 342 µmol/L within 6 hours of birth). All newborns with severe hyperbilirubinemia were hospitalized and underwent phototherapy. The mothers of all newborns had a gestational age ≥ 35 weeks. Hospitalization included artificial feeding, and breastfeeding was rare (P < .0001). ABO incompatibility ("O" blood type for mother and either "A" or "AB" or "B" blood type for newborn, P = .0411), G6PD deficiency (G6PD/6-phosphogluconate dehydrogenase ≤ 1.0 in quantitative assay, P = .0422), Rh incompatibility (the mother's blood type was Rh negative and newborn blood type was Rh positive, P = .0416), fewer genotype rs4149056 frequencies (P = .0452), higher genotype rs2306283 frequencies (P = .0461), and higher genotype rs1805173 frequencies (P = .0471) were independent parameter for early onset severe hyperbilirubinemia of newborns. The prevalence of early onset severe hyperbilirubinemia in Chinese newborns is 13% in the East China region. Blood incompatibility, G6PD deficiency, fewer genotype rs4149056 frequencies, higher genotype rs2306283 frequencies, and higher genotype rs1805173 frequencies were independent predictors of early onset severe hyperbilirubinemia among newborns in the East China region (Level of Evidence: IV; Technical Efficacy: Stage 5).

Prevalence of G6PD deficiency and submicroscopic malaria parasites carriage in malaria hotspot area in Northwest, Tanzania.

BACKGROUND: The use of primaquine for mass drug administration (MDA) is being considered as a key strategy for malaria elimination. In addition to being the only drug active against the dormant and relapsing forms of Plasmodium vivax, primaquine is the sole potent drug against mature/infectious Plasmodium falciparum gametocytes. It may prevent onward transmission and help contain the spread of artemisinin resistance. However, higher dose of primaquine is associated with the risk of acute haemolytic anaemia in individuals with a deficiency in glucose-6-phosphate dehydrogenase. In many P. falciparum endemic areas there is paucity of information about the distribution of individuals at risk of primaquine-induced haemolysis at higher dose 45 mg of primaquine. METHODS: A retrospective cross-sectional study was carried out using archived samples to establish the prevalence of G6PD deficiency in a malaria hotspot area in Misungwi district, located in Mwanza region, Tanzania. Blood samples collected from individuals recruited between August and November 2010 were genotyped for G6PD deficiency and submicroscopic parasites carriage using polymerase chain reaction. RESULTS: A total of 263 individuals aged between 0 and 87 were recruited. The overall prevalence of the X-linked G6PD A- mutation was 83.7% (220/263) wild type, 8% (21/263) heterozygous and 8.4% (22/263) homozygous or hemizygous. Although, assessment of the enzymatic activity to assign the phenotypes according to severity and clinical manifestation as per WHO was not carried out, the overall genotype and allele frequency for the G6PD deficiency was 16.4% and 13. 2%, respectively. There was no statistically significant difference in among the different G6PD genotypes (p > 0.05). Out of 248 samples analysed for submicroscopic parasites carriage, 58.1% (144/248) were P. falciparum positive by PCR. G6PD heterozygous deficiency were associated with carriage of submicroscopic P. falciparum (p = 0.029). CONCLUSIONS: This study showed that 16.4% of the population in this part of North-western Tanzania carry the G6PD A- mutation, within the range of 15-32% seen in other parts of Africa. G6PD gene mutation is widespread and heterogeneous across the study area where primaquine would be valuable for malaria control and elimination. The maps and population estimates presented here reflect potential risk of higher dose of primaquine being associated with the risk of acute haemolytic anaemia (AHA) in individuals with a deficiency in glucose-6-phosphate dehydrogenase and call further research on mapping of G6PD deficiency in Tanzania. Therefore, screening and education programmes for G6PD deficiency is warranted in a programme of malaria elimination using a higher primaquine dose.

Molecular characterization of G6PD mutations identifies new mutations and a high frequency of intronic variants in Thai females.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked enzymopathy caused by mutations in the G6PD gene. A medical concern associated with G6PD deficiency is acute hemolytic anemia induced by certain foods, drugs, and infections. Although phenotypic tests can correctly identify hemizygous males, as well as homozygous and compound heterozygous females, heterozygous females with a wide range of G6PD activity may be misclassified as normal. This study aimed to develop multiplex high-resolution melting (HRM) analyses to enable the accurate detection of G6PD mutations, especially among females with heterozygous deficiency. Multiplex HRM assays were developed to detect six G6PD variants, i.e., G6PD Gaohe (c.95A>G), G6PD Chinese-4 (c.392G>T), G6PD Mahidol (c.487G>A), G6PD Viangchan (c.871G>A), G6PD Chinese-5 (c.1024C>T), and G6PD Union (c.1360C>T) in two reactions. The assays were validated and then applied to genotype G6PD mutations in 248 Thai females. The sensitivity of the HRM assays developed was 100% [95% confidence interval (CI): 94.40%-100%] with a specificity of 100% (95% CI: 88.78%-100%) for detecting these six mutations. The prevalence of G6PD deficiency was estimated as 3.63% (9/248) for G6PD deficiency and 31.05% (77/248) for intermediate deficiency by phenotypic assay. The developed HRM assays identified three participants with normal enzyme activity as heterozygous for G6PD Viangchan. Interestingly, a deletion in intron 5 nucleotide position 637/638 (c.486-34delT) was also detected by the developed HRM assays. G6PD genotyping revealed a total of 12 G6PD genotypes, with a high prevalence of intronic variants. Our results suggested that HRM analysis-based genotyping is a simple and reliable approach for detecting G6PD mutations, and could be used to prevent the misdiagnosis of heterozygous females by phenotypic assay. This study also sheds light on the possibility of overlooking intronic variants, which could affect G6PD expression and contribute to enzyme deficiency.

Molecular Characterization of Erythrocyte Glucose-6-Phosphate Dehydrogenase Deficiency in Different Ethnic Groups of Blood Donors in Mauritania.

BACKGROUND: Glucose-6-phosphate-dehydrogenase (G6PD) deficiency is the most frequent enzymopathy worldwide; it is a genetic disorder that affects red blood cells and causes hemolysis. Here, we conducted a study on G6PD-deficient subjects in Mauritania to evaluate the molecular characteristics associated with a deficiency in this enzyme and the frequency of nucleotide polymorphisms in the glucose-6-phosphate dehydrogenase gene. METHOD AND MATERIALS: A total of 943 blood samples were collected from blood donors (803 males and 140 females; 364 white Moors; 439 black Moors; 112 Pulaar; 18 Wolof; 10 Soninke). All blood samples were analyzed using a rapid screening test. G6PD status was analyzed quantitatively by the Randox G6PD test. Samples deficient in G6PD were extracted from the whole blood samples and subjected to DNA genotyping. The most frequent G6PD variants were determined by two molecular techniques: restriction fragment length polymorphism (RFLP) and multiplex PCR using the GENESPARK G6PD African kit. A total of six single nucleotide polymorphisms (SNPs) (G202A, A376G, A542T, G680T, C563T, and T968C) were identified. RESULTS: The prevalence of G6PD deficiency in this population sample was 8.1%. The most common mutation was A376G/202A and was characterized by the G6PD A-phenotype, which is more common in the G6PD-deficient black Moors population. The wilaya in Nouakchott was the most affected among the 13 wilayas studied. CONCLUSIONS: This study shows, for the first time, the presence of the G680T mutation.

Genetic basis and spatial distribution of glucose-6-phosphate dehydrogenase deficiency in ecuadorian ethnic groups: a malaria perspective.

BACKGROUND: Glucose-6-phosphate dehydrogenase deficiency (G6PDd) is an X-linked disorder affecting over 400 million people worldwide. Individuals with molecular variants associated with reduced enzymatic activity are susceptible to oxidative stress in red blood cells, thereby increasing the risk of pathophysiological conditions and toxicity to anti-malarial treatments. Globally, the prevalence of G6PDd varies among populations. Accordingly, this study aims to characterize G6PDd distribution within the Ecuadorian population and to describe the spatial distribution of reported malaria cases. METHODS: Molecular variants associated with G6PDd were genotyped in 581 individuals from Afro-Ecuadorian, Indigenous, Mestizo, and Montubio ethnic groups. Additionally, spatial analysis was conducted to identify significant malaria clusters with high incidence rates across Ecuador, using data collected from 2010 to 2021. RESULTS: The A- c.202G > A and A- c.968T > C variants underpin the genetic basis of G6PDd in the studied population. The overall prevalence of G6PDd was 4.6% in the entire population. However, this frequency increased to 19.2% among Afro-Ecuadorian people. Spatial analysis revealed 12 malaria clusters, primarily located in the north of the country and its Amazon region, with relative risks of infection of 2.02 to 87.88. CONCLUSIONS: The findings of this study hold significant implications for public health interventions, treatment strategies, and targeted efforts to mitigate the burden of malaria in Ecuador. The high prevalence of G6PDd among Afro-Ecuadorian groups in the northern endemic areas necessitates the development of comprehensive malaria eradication strategies tailored to this geographical region.

Glucose-6-phosphate dehydrogenase deficiency and long-term risk of immune-related disorders.

Introduction: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked enzymatic disorder that is particularly prevalent in Africa, Asia, and the Middle East. This study aimed to assess the long-term health risks associated with G6PD deficiency. Methods: A retrospective cohort study was conducted using data from a national healthcare provider in Israel (Leumit Health Services). A total of 7,473 G6PD-deficient individuals were matched with 29,892 control subjects in a 1:4 ratio, based on age, gender, socioeconomic status, and ethnic groups. The exposure of interest was recorded G6PD diagnosis or positive G6PD diagnostic test. The main outcomes and measures included rates of infectious diseases, allergic conditions, and autoimmune disorders between 2002 and 2022. Results: Significantly increased rates were observed for autoimmune disorders, infectious diseases, and allergic conditions in G6PD-deficient individuals compared to the control group. Specifically, notable increases were observed for rheumatoid arthritis (odds ratio [OR] 2.41, p<0.001), systemic lupus erythematosus (OR 4.56, p<0.001), scleroderma (OR 6.87, p<0.001), pernicious anemia (OR 18.70, p<0.001), fibromyalgia (OR 1.98, p<0.001), Graves' disease (OR 1.46, p=0.001), and Hashimoto's thyroiditis (OR 1.26, p=0.001). These findings were supported by elevated rates of positive autoimmune serology and higher utilization of medications commonly used to treat autoimmune conditions in the G6PD-deficient group. Discussion: In conclusion, individuals with G6PD deficiency are at a higher risk of developing autoimmune disorders, infectious diseases, and allergic conditions. This large-scale observational study provides valuable insights into the comprehensive association between G6PD deficiency and infectious and immune-related diseases. The findings emphasize the importance of considering G6PD deficiency as a potential risk factor in clinical practice and further research is warranted to better understand the underlying mechanisms of these associations.

Mutation spectrum and enzyme profiling of G6PD deficiency in neonates of north India: a prospective study.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common X-linked disorder with well-established clinical and allelic heterogeneity and ethnic disparity. With ~390,000 annual births with G6PD deficiency in India, it emerges as the most predictable and preventable inbornmetabolic error. Disease prevalence and mutation spectrum have been reasonably reported fromcentral, western and southern parts of India and are mostly retrospective studies.Although prevalence data fromnorth India is available, there is paucity of data on the mutation spectrum and genotype-phenotype correlation (GxP). Thus, we aimed at establishing the clinical and mutation profiles for G6PD, as a part of a large prospective newborn screening study conducted between 2014 and 2016 across hospitals in Delhi, India. G6PD activity levels were measured at 24-48 h of life for ~200,000 neonates using Victor 2D and/or Genomic Screening Processor followed by confirmatory spectrophotometric analysis usingRBClysates of the respective neonates based on clinical symptoms.Asubset of 570 enzyme deficient neonates were screened formutations by polymerase chain reaction-restriction fragment length polymorphismand/or Sanger sequencing.Mediterraneanwas the most common mutation (n=318; 55.8%) with the lowest enzyme activity and most severe phenotype, followed by G6PD Orissa (n=187;32.8%); Kerala-Kalyan (n=25); Jammu (n=24);Mahidol (n=14); Chattam(n=1) andNilgiri/Coimbra (n=1).Of the 163 intramural neonates followed up, 68 developed clinical jaundice. However, no correlation was observed between jaundice and enzyme level. Notable outcome of this first ever prospective screening approach for G6PD deficiency in neonates may help in prediction of disease severity and appropriate timely management.