Screening For Glucose-6-phosphate Dehydrogenase Deficiency Research Articles

Screening and the analysis of genotypic and phenotypic characterization of glucose-6-phosphate dehydrogenase (G6PD) deficiency in Fujian province, China

IntroductionGlucose-6-phosphate dehydrogenase (G6PD) deficiency is a common X-linked hereditary disorder in southern China. However, the incidence rate of G6PD deficiency and the frequency of the most common G6PD gene variants vary widely. The purpose of this study was to investigate the prevalence, genotype, and phenotypic features of G6PD deficiency in neonates in Fujian province, southeastern China.MethodsThis retrospective cohort study enrolled 2,789,002 newborns (1,521,431 males and 1,267,571 females) based on the newborn screening program for G6PD deficiency in Fujian Province between January 2010 and December 2021.ResultsOf the 2,789,002 newborns enrolled, 26,437 cases were diagnosed (22,939 males and 3,498 females), and the estimated prevalence of G6PD deficiency in Fujian province was 0.95%. The prevalence was significantly higher among males (1.51%) than in females (0.28%) (p < 0.00001). Among the 3,198 patients with G6PD deficiency, 3,092 cases (2,145 males and 947 females) were detected to have G6PD gene variants. The top six prevalent genotypes identified represented 90.84% (2095/3,198) of the total and included c.1376G > T (44.93%), c.1388G > A (18.42%), c.1024C > T (9.32%), c.95A > G (8.69%), c.392G > T (5.25%), and c.871G > A (4.22%). The frequency of genotypes with c.1388G > A, c.1024C > T, and c.871G > A was higher in males in the Fujian province than in females, while the frequency of genotypes with c.1376G > T was lower. Furthermore, when comparing the enzyme activities of the top six prevalent genotypes, there were significant differences in the enzyme activities among the genotypes of male hemizygotes and female heterozygotes. According to the new classification of G6PD variants proposed by the World Health Organization (WHO), the variants with c.1376G > T, c.95A > G, and c.871G > A were recognized as Class A, while the c.392G > T, c.1388G > A, and c.1024C > T were recognized as Class B.DiscussionTo the best of our knowledge, this study is the first to systematically describe the overview of epidemiological characteristics of newborn G6PD deficiency in Fujian province, China, including the screening rate, incidence rate, and variant spectrum. Additionally, we elucidated the relationship between the distribution of enzyme activity with specific mutations and their WHO classification patterns. Our results could provide strategies for screening, diagnosis, and genetic counseling of G6PD deficiency in this area.

Implementation of Universal Screening for G6PD Deficiency in Newborns.

Implementation of Universal Screening for G6PD Deficiency in Newborns.

Associations between COVID-19 and Glucose-6-Phosphate Dehydrogenase Activity in Brazil.

Glucose-6 phosphate dehydrogenase deficiency (G6PDd) was suggested as a risk factor for severe disease in patients with COVID-19. We evaluated clinical outcomes and glucose-6 phosphate dehydrogenase (G6PD) activity during and after illness in patients with COVID-19. This prospective cohort study included adult participants (≥18 years old) who had clinical and/or radiological COVID-19 findings or positive reverse transcription-polymerase chain reaction results. Epidemiological and clinical data were extracted from electronic medical records. Glucose-6 phosphate dehydrogenase activity was measured using SD Biosensor STANDARD G6PD® equipment on admission and 1 year after discharge. Samples were genotyped for the three most common single nucleotide polymorphisms for G6PDd in the Brazilian Amazon. Seven hundred fifty-three patients were included, of whom 123 (16.3%) were G6PD deficient. There was no difference between groups regarding the risks of hospitalization (P = 0.740) or invasive mechanical ventilation (P = 0.31), but the risk of death was greater in patients with normal G6PD levels (P = 0.022). Only 29 of 116 participants (25%) carried the African G6PDd genotype. Of 30 participants tested as G6PD deficient during disease, only 11 (36.7%) results agreed 1 year after discharge. In conclusion, this study does not demonstrate an association of G6PDd with severity of COVID-19. Limitations of the test for detecting enzyme levels during COVID-19 illness were demonstrated by genotyping and retesting after the disease period. Care must be taken when screening for G6PDd in patients with acute COVID-19.

Clinical performance validation of the STANDARD G6PD test: A multi-country pooled analysis.

Screening for G6PD deficiency can inform disease management including malaria. Treatment with the antimalarial drugs primaquine and tafenoquine can be guided by point-of-care testing for G6PD deficiency. Data from similar clinical studies evaluating the performance of the STANDARD G6PD Test (SD Biosensor, South Korea) conducted in Bangladesh, Brazil, Ethiopia, India, Thailand, the United Kingdom, and the United States were pooled. Test performance was assessed in a retrospective analysis on capillary and venous specimens. All study sites used spectrophotometry for reference G6PD testing, and either the HemoCue or complete blood count for reference hemoglobin measurement. The sensitivity of the STANDARD G6PD Test using the manufacturer thresholds for G6PD deficient and intermediate cases in capillary specimens from 4212 study participants was 100% (95% Confidence Interval (CI): 97.5%-100%) for G6PD deficient cases with <30% activity and 77% (95% CI 66.8%-85.4%) for females with intermediate activity between 30%-70%. Specificity was 98.1% (95% CI 97.6%-98.5%) and 92.8% (95% CI 91.6%-93.9%) for G6PD deficient individuals and intermediate females, respectively. Out of 20 G6PD intermediate females with false normal results, 12 had activity levels >60% on the reference assay. The negative predictive value for females with G6PD activity >60% was 99.6% (95% CI 99.1%-99.8%) on capillary specimens. Sensitivity among 396 P. vivax malaria cases was 100% (69.2%-100.0%) for both deficient and intermediate cases. Across the full dataset, 37% of those classified as G6PD deficient or intermediate resulted from true normal cases. Despite this, over 95% of cases would receive correct treatment with primaquine, over 87% of cases would receive correct treatment with tafenoquine, and no true G6PD deficient cases would be treated inappropriately based on the result of the STANDARD G6PD Test. The STANDARD G6PD Test enables safe access to drugs which are contraindicated for individuals with G6PD deficiency. Operational considerations will inform test uptake in specific settings.

Rasburicase-induced hemolytic anemia and methemoglobinemia: a systematic review of current reports.

Since the FDA's approval of rasburicase use for treatment of tumor lysis syndrome (TLS), multiple cases of rasburicase-induced methemoglobinemia and hemolytic anemia have been reported among patients with G6PD deficiency. This study aims to provide a systematic review of cases reporting such adverse reactions to rasburicase. A literature review of published cases in PubMed, Embase, Cochrane, and Web of Science was conducted. Descriptive studies reporting cases of rasburicase-induced methemoglobinemia and/or hemolytic anemia in English were analyzed and summarized in this study. Forty-three cases, including a case from our institution, were included in this study. Most cases (60.5%) received rasburicase for TLS treatment. Almost all patients (93.8%) were tested for G6PD after rasburicase administration. The median time to symptom onset was 24 h. The median methemoglobin level was 10%, peaking after a median of 24 h. The median hemoglobin nadir was 6.1 g/dL, and most patients (n = 32) required blood transfusion. Out of 39 cases with reported outcomes, 35 patients (89.7%) recovered, while four patients (three females and one male) died. The median time to recovery was 4.5 days while the median time to death was 8 days. Screening for G6PD deficiency among high-risk patients is important but not practical in acutely severe settings. When prior screening for G6PD deficiency is not feasible, close monitoring for methemoglobinemia and hemolytic anemia is recommended. Exchange transfusion is increasingly reported as a potentially successful therapeutic modality. Ascorbic acid may provide limited benefits. Methylene blue should be avoided as it may exacerbate hemolysis among these patients.

Newborn screening for G6PD deficiency in HeFei, FuYang and AnQing, China: Prevalence, cut-off value, variant spectrum.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked recessive Mendelian genetic disorder characterized by neonatal jaundice and hemolytic anemia, affecting more than 400 million people worldwide. The purpose of this research was to investigate prevalence rates of G6PD deficiency and to evaluate and establish specific cut-off values in early prediction of G6PD deficiency by regions (HeFei, FuYang, AnQing) on different seasons, as well as to investigate the frequencies of G6PD gene mutations among three regions mentioned above. A total of 31,482 neonates (21,402, 7680, and 2340 for HeFei, FuYang, and AnQing cities, respectively) were recruited. Positive subjects were recalled to attend genetic tests for diagnosis. G6PD activity on the Genetic screening processor (GSP analyzer, 2021-0010) was measured following the manufactureržs protocol. The cut-off value was first set to 35 U/dL. The receiver operating characteristics (ROC) curve was employed to assess and compare the efficiency in predicting G6PD deficiency among HeFei, FuYang, and AnQing cities in different seasons.

The effect of phototherapy on neonatal calcium and bilirubin levels: a comparison between patients with low and normal G6PD levels

Introduction: Iran is among countries that report a higher prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency, ranging from 2.28% to 30.80%. This study aimed to estimate the general prevalence of G6PD deficiency in newborns with jaundice who were hospitalised in southeast Iran. Methods: This was a prospective study. A total of 100 newborns (boys and girls) with hyperbilirubinaemia, presented to Amir Al-Mo’menin Hospital in 2006 and 2007, were selected for the study. Age, gender, weight, time of jaundice, the maximum level of direct bilirubin, and the total level of bilirubin among the newborns were recorded, and the data were analysed by SPSS. Results: A total of 100 jaundice neonates, including 46 girls and 54 boys, were enrolled. Twenty-two percent of these patients, including 18 (82%) boys and 4 (18%) girls, showed low levels of G6PD. The overall mean bilirubin level was 15.45 ± 3.43 mg/dL among neonates with low G6PD levels, while it was 19.21 ± 3.34 mg/dL in patients with normal G6PD levels, which showed a significant difference (p &lt; 0.05). Conclusion: The prevalence of G6PD deficiency in neonates with jaundice in our study was 22%, which was higher compared to other regions. We propose G6PD deficiency screening for the prevention of its complications. We also suggest assessing calcium levels following phototherapy, given the higher prevalence of hypocalcaemia.

Secondary Reporting of G6PD Deficiency on Newborn Screening

In April 2019, the Alberta Newborn Screening Program expanded to include screening for classic galactosemia using a two-tier screening approach. This approach secondarily identifies infants with glucose-6-phosphate dehydrogenase (G6PD) deficiency. The goals of this study were (i) to evaluate the performance of a two-tier galactosemia screening protocol, (ii) to explore the impact on and acceptability to families of reporting G6PD deficiency as a secondary finding, and (iii) assess the communication and follow-up process for positive G6PD deficiency screening results. The two-tiered galactosemia approach increased the positive predictive value (PPV) for galactosemia from 8% to 79%. An additional 119 positive newborn screen results were reported for G6PD deficiency with a PPV of 92%. The results show that there may be utility in reporting G6PD deficiency results. Most parents who participated in the study reported having some residual worry around the unexpected diagnosis; however, all thought it was helpful to know of their child's diagnosis of G6PD deficiency. Finally, the communication process for reporting G6PD deficiency newborn screen results was determined to result in appropriate follow up of infants.

Study protocol for development of an options assessment toolkit (OAT) for national malaria programs in Asia Pacific to determine best combinations of vivax radical cure for their given contexts.

Recent advances in G6PD deficiency screening and treatment are rapidly changing the landscape of radical cure of vivax malaria available for National Malaria Programs (NMPs). While NMPs await the WHO's global policy guidance on these advances, they will also need to consider different contextual factors related to the vivax burden, health system capacity, and resources available to support changes to their policies and practices. Therefore, we aim to develop an Options Assessment Toolkit (OAT) that enables NMPs to systematically determine optimal radical cure options for their given environments and potentially reduce decision-making delays. This protocol outlines the OAT development process. Utilizing participatory research methods, the OAT will be developed in four phases where the NMPs and experts will have active roles in designing the research process and the toolkit. In the first phase, an essential list of epidemiological, health system, and political & economic factors will be identified. In the second phase, 2-3 NMPs will be consulted to determine the relative priority and measurability of these factors. These factors and their threshold criteria will be validated with experts using a modified e-Delphi approach. In addition, 4-5 scenarios representing country contexts in the Asia Pacific region will be developed to obtain the expert-recommended radical cure options for each scenario. In the third phase, additional components of OAT, such as policy evaluation criteria, latest information on new radical cure options, and others, will be finalized. The OAT will be pilot-tested with other Asia Pacific NMPs in the final phase. Human Research Ethics Committee approval has been received from the Northern Territory, Department of Health, and Menzies School of Health Research (HREC Reference Number: 2022-4245). The OAT will be made available for the NMPs, introduced at the APMEN Vivax Working Group annual meeting, and reported in international journals.

Malaria in Children: Updates on Management and Prevention.

Malaria in Children: Updates on Management and Prevention.

Screening of G6PD Deficiency in Newborns at a Tertiary Care Teaching Hospital in Assam, North East India: A Cross-sectional Study

Introduction: Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency is the most frequently encountered enzymopathy in humans. It is closely linked to neonatal jaundice, chronic non-spherocytic haemolytic anaemia, and acute haemolytic anaemia. G6PD deficiency is a common cause of jaundice among neonates. Aim: To screen for G6PD deficiency among newborns at a tertiary care teaching centre in Assam. Materials and Methods: This hospital-based cross-sectional study was conducted in the postnatal ward of the Department of Paediatrics at Medical College &amp; Hospital, Dibrugarh, Assam, India, from June 2021 to May 2022. A randomly selected sample of 630 term neonates aged between 24 hours and 7 days of life was included in the study. A 2ml blood sample was collected in an Ethylenediamine Tetra-acetic Acid (EDTA) vial from each neonate, and G6PD enzyme activity was estimated using the Kinetic Method with a commercially available G-six kit. Newborns with G6PD enzyme activity values less than 6.4 U/g Haemoglobin (Hb) were considered G6PD deficient. Data, including age, sex, religion, Total Serum Bilirubin (TSB/NBIL), G6PD activity, and Hb of the neonates, were entered into pre-designed forms. The data were analysed using the Chi-square test. Results: Among the 630 screened neonates, 48 were found to be G6PD deficient, of which the majority were males (34 males, 14 females), resulting in a male-to-female ratio of 2.4:1. The occurrence of G6PD deficiency was 7.62%. The mean G6PD enzyme activity in deficient neonates was 4.53±1.17 U/g Hb. Conclusion: This study identified a significant occurrence of G6PD deficiency in newborns, including females. The mean G6PD enzyme activity in deficient neonates was significantly lower than in normal cases.

A community based study on haemoglobinopathies and G6PD deficiency among particularly vulnerable tribal groups in hard-to-reach malaria endemic areas of Odisha, India: implications on malaria control

BackgroundHaemoglobinopathies and G6PD deficiency are inherited disorders found mostly in malaria-endemic areas among different tribal groups of India. However, epidemiological data specific to Particularly Vulnerable Tribal Groups (PVTGs), important for planning and implementing malaria programmes, is limited. Therefore, the present community-based study aimed to assess the prevalence of haemoglobinopathies and G6PD deficiency among the 13 PVTGs found in the state of Odisha, reporting the maximum malaria cases in the country.MethodsThis cross-sectional study was conducted from July 2018 to February 2019 in 12 districts, home to all 13 PVTGs, in an estimated sample size of 1461, selected two-stage sampling method. Detection of haemoglobinopathies was done by the variant analyser. Screening of G6PD deficiency was carried out using DPIP method followed by quantification using spectrophotometry. The PCR–RFLP technology was used to determine variant of G6PD deficiency and haplotype analysis of sickle cell, while ARMS-PCR and GAP-PCR was used for detecting the mutation pattern in β-thalassaemia and α-thalassaemia respectively. The diagnosis of malaria was done by Pf-PAN RDT as point of care, followed by nPCR for confirmation and Plasmodium species identification.ResultsThe prevalence of sickle cell heterozygotes (AS) was 3.4%, sickle cell homozygous (SS) 0.1%, β-thalassaemia heterozygotes 0.3%, HbS/β-thalassaemia compound heterozygote 0.07%, HbS-α-thalassaemia 2.1%, G6PD deficiency 3.2% and malaria 8.1%. Molecular characterization of βS revealed the presence of Arab-Indian haplotype in all HbS cases and IVS 1–5 G → C mutation in all β-thalassaemia cases. In case of α-thal, αα/α-3.7 gene deletion was most frequent (38%), followed by αα/α-4.2 (18%) and α-3.7/α-3.7 (4%). The frequency of G6PD Orissa (131C → G) mutation was found to be 97.9% and G6PD Mediterranean (563C → T) 2.1%. Around 57.4% of G6PD deficient individuals and 16% of the AS were found to be malaria positive.ConclusionThe present study reveals wide spread prevalence of sickle cell anaemia, α-thalassaemia, G6PD deficiency and malaria in the studied population. Moderate to high prevalence of G6PD deficiency and malaria warrants G6PD testing before treating with primaquine (PQ) for radical cure of Plasmodium vivax. Screening and counselling for HbS is required for the PVTGs of Odisha.

Quantitative G6PD Deficiency Screening in Routine Malaria Diagnostic Units in the Brazilian Amazon (SAFEPRIM): An Operational Mixed-Methods Study.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency testing is not routinely performed before primaquine treatment in most Plasmodium vivax endemic areas, despite the risk of primaquine-associated hemolysis. This is due to the operational challenges associated with pragmatic G6PD testing and as such needs to be addressed. This mixed-methods operational study was aimed at implementing the quantitative point-of-care StandardTM G6PD (SD Biosensor, Korea) screening test in malaria treatment units (MTUs) in the municipalities of Rio Preto da Eva and Mâncio Lima, in the Brazilian Amazon, between mid-January 2020 and December 2020. In total, 1286 P. vivax cases were treated based on the Standard G6PD test: 1230 had activity equal to or greater than 4.0 U/g Hb, and 56 less than 4.0 U/g Hb. No G6PD deficient (G6PDd) genotypes were found in 96 samples from the 1230, and only 21 of the 56 G6PDd cases had confirmed G6PDd genotypes. Evaluations were conducted on the proficiency of health care professionals (HCPs) training to perform the test, the reliability of testing performed in the field, and the perceptions of HCPs and patients about the implementation. Post-training proficiency was 73.4% after a 4-hour training session. This study revealed that locations with lower malaria caseloads will need regular refresher training. The test was well accepted by both HCPs and patients. Signs and symptoms of hemolysis were not always associated with malaria treatment drugs by HCPs and patients. Point-of-care quantitative G6PD testing can be performed at MTUs in the Brazilian Amazon to inform treatment decisions with primaquine. Limitations related to technical and cultural aspects need to be addressed further when expanding screening to larger areas.

Reduction of Missed Diagnosis of G6PD Deficiency in Heterozygous Females by G6PD/6PGD Ratio Assay Combined with Amplification Refractory Mutation System PCR

Objective: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked genetic disorder that results in impaired enzyme activity. The G6PD/6PGD ratio assay was routinely used for G6PD deficiency screening in China, but there is an apparent defect of missed diagnosis in heterozygous females. The study aims to explore the means to improve its accuracy. Methods: A total of 4,161 Chinese females of childbearing age were collected in this retrospective study. All samples were first subjected to G6PD/6PGD ratio assay and then screened by amplification refractory mutation system PCR (ARMS-PCR) for six hotspot mutants in Chinese population (c.1376G>T, c.1388G>A, c.95A>G, c.1024C>T, c.392G>T, and c.871G>A). For the samples with G6PD/6PGD ratio<1.0 and no mutations were found by ARMS-PCR, next-generation sequencing (NGS) was performed. Sanger sequencing was finally used to verify all the variants. Results: The prevalence of G6PD deficiency in Shenzhen females of childbearing age was 7.31%. The proportion of the six hotspot mutations accounted for 98.03% of all 304 G6PD variants carriers. Taking the ARMS-PCR/NGS results as a reference, the missed diagnosis rate of the G6PD/6PGD ratio assay was 33.88%. Using ARMS-PCR to retest the samples with a G6PD/6PGD ratio between 1.00 and ∼1.10 or 1.00 and ∼1.15 could reduce the missed diagnosis rate from the original 33.88% to 18.09% or 12.05% separately. Conclusion: ARMS-PCR is an appropriate supplementary method for discovering most carriers missed by the G6PD/6PGD ratio assay.

Prevalence of G6PD deficiency and G6PD variants amongst the southern Thai population.

BackgroundGlucose-6-phosphate dehydrogenase (G6PD) is an enzyme essential for NADPH production and protecting cells, especially red blood cells, from free radicals. The oxidative stress from drugs, chemicals, and infections can induce red blood cell hemolysis in G6PD deficiency patients, causing a genetic disorder.ObjectivesThis study aims to provide more information on G6PD deficiency prevalence and the G6PD variants in the southern Thai population.MethodsFive hundred and twenty healthy subjects in 14 provinces in the southern part of Thailand participated in the study. EDTA-blood samples were collected for a hematological parameters study, G6PD deficiency screening, and a molecular study for G6PD mutation. G6PD deficiency screening was tested using a fluorescent spot test. The types of G6PD mutation were identified by the allele-specific PCR method.ResultsThe prevalence of G6PD deficiency in southern Thailand was 6.1% (14/228) in males and 9.6% (28/292) in females. Two homozygous and 26 heterozygous G6PD deficiencies were found in females. G6PD Viangchan (871G>A) was the most common variant with 43%, followed by G6PD Mahidol (487G>A), 24% with an allele frequency of 0.025 and 0.012, respectively. Uncharacterized mutations existed in three samples. The study volunteers had anemia in 36.6% (107/292) females and 7.5% (17/228) males. Among G6PD deficiency subjects, only ten partial G6PD deficiency females had mild anemia.ConclusionsThis study suggests that the prevalence of G6PD deficiency in southern Thailand aligns with that of other parts of Thailand. Newborn screening for G6PD deficiency is recommended for personal information and medical reference to prevent acute hemolysis from oxidative stressors.

DIAGNOSTIC ACCURACY COMPARISON OF THE QUANTITATIVE POINT-OF-CARE ECO G6PD AND BREWERS TEST FOR ASSESSMENT OF G6PD DEFICIENCY IN INFECTIOUS DISEASES

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked, hereditary condition caused by mutations in the G6PD gene, that results in protein variants with different enzyme activity levels. G6PD provides reducing power to NADPH (reduced form of nicotinamide adenine dinucleotide phosphate). NADPH effect is critical in red blood cells (RBC) due to the absence of a nucleus. Clinical manifestations are usually mild and are induced by an exogenous agent, such as drugs, infections, or dietary (fava beans). The G6PD deficiency diagnosis is crucial in infectious diseases because both infections and treatment can induce acute hemolysis. Rarely, life-threatening cases can require transfusions of RBC and hemodialysis. The gold standard for the measurement of G6PD activity is a quantitative UV spectrophotometric assay, however, it is inaccessible in most cases. Methemoglobin reduction test (Brewer's test) is a qualitative spot test most used for G6PD deficiency screening, but is imprecise, requires a cold chain, some laboratory infrastructure, trained personnel, and is time-costing. Point-of-care (POC) is a simple and fast semi-quantitative test that is becoming increasingly important when a prompt diagnosis is required and in health care of out-of-reach communities. To compare the diagnostic accuracy of the quantitative POC ECO and Brewers test for assessment of G6PD deficiency. A cross-sectional diagnostic accuracy study was enrolled between May 2020 and December 2021 at the Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz. Individuals older than 17 years old with a suspicious diagnosis of an infectious disease were eligible. 125 convenience blood samples were tested to compare concordance analysis between Brewers test and POC STANDARD G6PD. The exclusion criteria were hemoglobin concentration < 7.0 g/dL due to technical device limitations. A total of 125 subjects (38 females and 87 males) were recruited. The median age was 42.0 years (range 18–76) in females and 45.0 years (range 19–78) in males. The median of G6PD activity was 7.1 U/g Hb (0.2-17.5). We observed a trend of concordance between the G6PD status (deficient or normal), with low frequencies of discordances in the screenings. The strength of agreement between G6PD tests was classified as almost perfect in all participants (k = 0.82, IC95% = 0.66,0.97) and in subgroups female (k = 0.83, IC95% = 0.59,1.00) and male (k = 0.81, IC95% = 0.59,1.00). The total concordance percentage (number of concordances/total) was 95% in females, 97% in males, and 96% in all participants. Here, we demonstrate POC ECO G6PD test could be performed during medical consultation, guiding the most appropriate therapy almost immediately. In addition to saving time and having comparable results to Brewer's test, it could be performed even in remote areas and with scarce resources, dispensing minimum laboratory requirements. Our findings will be of value to diagnose conditions that could have life-threatening consequences if not timely recognized, such as before initiating primaquine for the treatment of malaria. Therefore, it can improve healthcare in vulnerable isolated communities. We observed a high concordance result between Brewers test and POC STANDARD G6PD, which is becoming the reference test to diagnose G6PD deficiency worldwide.

Evaluation of strategies for identification of infants with pathogenic glucose-6-phosphate dehydrogenase variants in China.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, which is caused by pathogenic variants of G6PD that result in decreased G6PD activity, is an X-linked inherited inborn error of metabolism that occurs worldwide. Individuals with G6PD deficiency and heterozygous females with normal G6PD activity (i.e., all individuals with pathogenic G6PD variants) are at risk of developing hemolytic anemia under increased oxidative challenge. However, this risk can be minimized by timely diagnosis. Currently, two assays are used to diagnose G6PD deficiency in China: evaluation of enzymatic activity and targeted genotyping. In terms of identification of all individuals with pathogenic G6PD variants, the performance and cost of different diagnostic strategies (isolated or combined evaluation of G6PD activity and G6PD genotyping) can vary, and these factors should be comprehensively evaluated. In this study, we examined 555 infants (437 males and 118 females) who were positive for the newborn screening of G6PD deficiency. We first evaluated the diagnostic performances of enzymatic testing and targeted genotyping. Both assays attained 100% specificities and positive predictive values for both male and female infants. In contrast, the sensitivities and negative predictive values (NPVs) of the diagnostic tests were different for male and female infants. For male infants, the sensitivities were 99.8 and 98.3%, and the NPVs were 94.1% and 69.6%, for enzymatic testing and targeted genotyping, respectively. For female infants, the sensitivities were 62.5% and 97.9%, and the NPVs were 37.9% and 91.7%, for enzymatic testing and targeted genotyping, respectively. We also evaluated the cost of the five different diagnostic strategies. The combination of G6PD activity testing of all infants, followed by genotyping of female infants with normal G6PD activity, attained high diagnostic sensitivity (99.8%) at a low cost (8.60 USD per diagnosed case). In the future, simultaneous examination of G6PD activity and whole-exon or whole-gene G6PD sequencing could become a standard clinical practice. Our data provide references for clinical practice on the standardization of current and future interventions for G6PD deficiency in China.

Glucose 6 phosphate dehydrogenase deficiency quantitative test in dried blood spot- a potential marker for adult unknown G6PD deficiency.

Glucose 6 Phosphate Dehydrogenase (G6PD) enzyme activity estimation in a freshly collected blood sample is the most widely used diagnostic method for the diagnosis of G6PD deficiency. The objective is to evaluate the need for newborn screening for G6PD deficiency over post-malarial diagnosis and the feasibility and reliability of using dried blood spots (DBS) as samples for screening. A total of 562 samples were analyzed for G6PD and parallel measurement of G6PD activity by the colorimetric method in whole blood and DBS was carried out in the neonatal subset. Among 466 adults, 27 (5.7%) showed G6PD deficiency, out of whom 22 (81.48%) were diagnosed after the malarial encounter. In the pediatric group, 8 neonates showed G6PD deficiency. G6PD activity estimated from DBS samples agreed with whole blood, with a statistically significant strong positive correlation. Screening of G6PD deficiency at birth to prevent future unwarranted complications, using DBS is feasible.

A comparative study between glucose 6-phosphate dehydrogenase deficient and normal term neonates with indirect hyperbilirubinemia in a rural tertiary care hospital of Eastern India

Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an important cause of neonatal indirect hyperbilirubinemia or even kernicterus leading to long-term neurological sequelae specially in countries like India where G6PD deficiency is quite prevalent. Aims and Objectives: We have planned this study to know the prevalence of G6PD deficiency among cases of neonatal jaundice and also to evaluate the difference between G6PD deficient and normal neonates with indirect hyperbilirubinemia in terms of laboratory parameters and need of phototherapy or exchange transfusion. Materials and Methods: This observational and cross-sectional study was done for a period of 1 year in the SNCU and NICU of a district Medical College of West Bengal among 200 term neonates presented with indirect hyperbilirubinemia. Birth weight, sex, hemoglobin, G6PD level, serum bilirubin at admission, phototherapy duration, and need for exchange transfusion were recorded along with other necessary parameters. Results: We found G6PD deficiency in 24 neonates (12%) out of 200 cases of neonatal jaundice, 20 of whom were male. There is a statistically significant difference in hemoglobin and serum bilirubin level between two groups. Difference in early presentation of jaundice within 24–48 h (66.7% vs. 34.1%) and need of prolonged phototherapy 72–96 h (45.83% vs. 7.4%) between G6PD deficient and normal group were statistically significant. Difference in requirement of exchange transfusion is not statistically significant. Conclusion: Early screening for G6PD deficiency should be considered in every neonates of G6PD deficient endemic countries so that we can predict the natural course of the jaundice in those G6PD deficient neonate and prevent complication by early initiation of phototherapy or exchange transfusion.

Cut-off values for diagnosis of G6PD deficiency by flow cytometry in Thai population

In heterozygous females, X-inactivation causes a change in glucose-6-phosphate dehydrogenase (G6PD) activity from normal to deficient. Most G6PD screening tests are used to accurately diagnose hemizygous males, but they are less reliable for diagnosing heterozygous females. This study established flow cytometric cut-off values for screening of G6PD deficiency in hemizygous males and heterozygous or homozygous females. We studied 205 (125 females, 80 males) leftover blood samples from quantitative methemoglobin reduction (MR) screening. G6PD gene mutations determined by multiplex amplification refractory mutation system-polymerase chain reaction and direct DNA sequencing were used as the gold standard reference. Accuracy of the test, including the sensitivity, specificity, and positive and negative predictive values, was analyzed using MedCalc software. The optimal cut-off values for classification of %red blood cells with normal G6PD activity or %bright cells into homozygous normal, heterozygous, and homozygous deficiency in females were 85.4–100%, 6.3–85.3%, and 0–6.2%, respectively (sensitivity 93.2%, specificity 100%). The cut-offs for classification into hemizygous normal and hemizygous deficiency in males were 76.5–100% and 0–76.4%, respectively (sensitivity 100%, specificity 96.5%). Flow cytometry can be used to differentiate heterozygous females with intermediate phenotype from homozygous females, but cannot distinguish between heterozygous females with extreme phenotype and homozygous females. By flow cytometry, heterozygous and homozygous deficiency was detected in 29.6% and 3.2% of females, respectively. Among males, hemizygous deficiency was found in 31.3%. Flow cytometry can be used to screen patients with G6PD deficiency, and reliably and efficiently identify heterozygous and homozygous females, and hemizygous males based on cellular G6PD activity.