Allosteric role of a structural NADP+ molecule in glucose-6-phosphate dehydrogenase activity.

Human glucose-6-phosphate dehydrogenase (G6PD) is the main cellular source of NADPH, and thus plays a key role in maintaining reduced glutathione to protect cells from oxidative stress disorders such as hemolytic anemia. G6PD is a multimeric enzyme that uses the cofactors ß-D-glucose 6-phosphate (G6P) and "catalytic" NADP+ (NADP+c), as well as a "structural" NADP+ (NADP+s) located ∼25 Å from the active site, to generate NADPH. While X-ray crystallographic and biochemical studies have revealed a role for NADP+s in maintaining the catalytic activity by stabilizing the multimeric G6PD conformation, other potential roles for NADP+s have not been evaluated. Here, we determined the high resolution cryo-electron microscopy structures of human wild-type G6PD in the absence of bound ligands and a catalytic G6PD-D200N mutant bound to NADP+c and NADP+s in the absence or presence of G6P. A comparison of these structures, together with previously reported structures, reveals that the unliganded human G6PD forms a mixture of dimers and tetramers with similar overall folds, and binding of NADP+s induces a structural ordering of a C-terminal extension region and allosterically regulates G6P binding and catalysis. These studies have implications for understanding G6PD deficiencies and for therapy of G6PD-mediated disorders.

Diagnosis and clinical management of enzymopathies.

At least 16 genetically determined conditions qualify as red blood cell enzymopathies. They range in frequency from ultrarare to rare, with the exception of glucose-6-phosphate dehydrogenase deficiency, which is very common. Nearly all these enzymopathies manifest as chronic hemolytic anemias, with an onset often in the neonatal period. The diagnosis can be quite easy, such as when a child presents with dark urine after eating fava beans, or it can be quite difficult, such as when an adult presents with mild anemia and gallstones. In general, 4 steps are recommended: (1) recognizing chronic hemolytic anemia; (2) excluding acquired causes; (3) excluding hemoglobinopathies and membranopathies; (4) pinpointing which red blood cell enzyme is deficient. Step 4 requires 1 or many enzyme assays; alternatively, DNA testing against an appropriate gene panel can combine steps 3 and 4. Most patients with a red blood cell enzymopathy can be managed by good supportive care, including blood transfusion, iron chelation when necessary, and splenectomy in selected cases; however, some patients have serious extraerythrocytic manifestations that are difficult to manage. In the absence of these, red blood cell enzymopathies are in principle amenable to hematopoietic stem cell transplantation and gene therapy/gene editing.

Prevalence of glucose-6-phosphate dehydrogenase deficiency (G6PDd), CareStart qualitative rapid diagnostic test performance, and genetic variants in two malaria-endemic areas in Sudan.

Glucose-6-phosphate dehydrogenase deficiency (G6PDd) is the most common enzymopathy globally, and deficient individuals may experience severe hemolysis following treatment with 8-aminoquinolines. With increasing evidence of Plasmodium vivax infections throughout sub-Saharan Africa, there is a pressing need for population-level data at on the prevalence of G6PDd. Such evidence-based data will guide the expansion of primaquine and potentially tafenoquine for radical cure of P. vivax infections. This study aimed to quantify G6PDd prevalence in two geographically distinct areas in Sudan, and evaluating the performance of a qualitative CareStart rapid diagnostic test as a point-of-care test. Blood samples were analyzed from 491 unrelated healthy persons in two malaria-endemic sites in eastern and central Sudan. A pre-structured questionnaire was used which included demographic data, risk factors and treatment history. G6PD levels were measured using spectrophotometry (SPINREACT) and first-generation qualitative CareStart rapid tests. G6PD variants (202 G>A; 376 A>G) were determined by PCR/RFLP, with a subset confirmed by Sanger sequencing. The prevalence of G6PDd by spectrophotometry was 5.5% (27/491; at 30% of adjusted male median, AMM); 27.3% (134/491; at 70% of AMM); and 13.1% (64/490) by qualitative CareStart rapid diagnostic test. The first-generation CareStart rapid diagnostic test had an overall sensitivity of 81.5% (95%CI: 61.9 to 93.7) and negative predictive value of 98.8% (97.3 to 99.6). All persons genotyped across both study sites were wild type for the G6PD G202 variant. For G6PD A376G all participants in New Halfa had wild type AA (100%), while in Khartoum the AA polymorphism was found in 90.7%; AG in 2.5%; and GG in 6.8%. Phenotypic G6PD B was detected in 100% of tested participants in New Halfa while in Khartoum, the phenotypes observed were B (96.2%), A (2.8%), and AB (1%). The African A- phenotype was not detected in this study population. Overall, G6PDd prevalence in Sudan is low-to-moderate but highly heterogeneous. Point-of-care testing with the qualitative CareStart rapid diagnostic test demonstrated moderate performance with moderate sensitivity and specificity but high negative predicative value. The two sites harbored primarily the African B phenotype. A country-wide survey is recommended to understand GP6PD deficiencies more comprehensively in Sudan.

Long-range structural defects by pathogenic mutations in most severe glucose-6-phosphate dehydrogenase deficiency.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common blood disorder, presenting multiple symptoms, including hemolytic anemia. It affects 400 million people worldwide, with more than 160 single mutations reported in G6PD. The most severe mutations (about 70) are classified as class I, leading to more than 90% loss of activity of the wild-type G6PD. The crystal structure of G6PD reveals these mutations are located away from the active site, concentrating around the noncatalytic NADP+-binding site and the dimer interface. However, the molecular mechanisms of class I mutant dysfunction have remained elusive, hindering the development of efficient therapies. To resolve this, we performed integral structural characterization of five G6PD mutants, including four class I mutants, associated with the noncatalytic NADP+ and dimerization, using crystallography, small-angle X-ray scattering (SAXS), cryogenic electron microscopy (cryo-EM), and biophysical analyses. Comparisons with the structure and properties of the wild-type enzyme, together with molecular dynamics simulations, bring forward a universal mechanism for this severe G6PD deficiency due to the class I mutations. We highlight the role of the noncatalytic NADP+-binding site that is crucial for stabilization and ordering two ß-strands in the dimer interface, which together communicate these distant structural aberrations to the active site through a network of additional interactions. This understanding elucidates potential paths for drug development targeting G6PD deficiency.

Evaluation of a flow cytometric test for G6PD-deficient erythrocytes.

OBJECTIVE: Glucose-6-phosphate dehydrogenase (G6PD) deficiency, an X-linked recessive disorder, is the commonest erythrocytic enzymopathy worldwide. Reliable diagnosis and severity prediction in G6PD-deficient/heterozygous females remain challenging. A recently developed flow cytometric test for G6PD deficiency has shown promise in precisely identifying deficient females. This paper presents our experiences with this test in a subtropical setting and presents a modification in flow cytometric data acquisition strategy. METHODS: The methaemoglobin reduction + ferryl Hb generation-based flow cytometric G6PD test was compared with the screening methaemoglobin reduction test (MRT) and confirmatory G6PD enzyme activity assay (EAA) in 20 G6PD-deficient males, 22 G6PD-heterozygous/deficient females and 20 controls. Stained cells were also assessed for bright/dim G6PD activity under a fluorescent microscope. RESULTS: Flow cytometry separated and quantified %bright cells in heterozygous/deficient females, objectively classifying them into 6 normal (>85% bright cells), 14 intermediate (10-85%) and two G6PD-deficient (<10% bright cells). Concordance with MRT was 89% (55/62 cases) and with EAA was 77% (48/62 cases). Fluorometrically predicted violet laser excitation (405-nm) with signal acquisition in the 425-475 nm region was a technical advancement noted for the first time in this paper. CONCLUSION: Flow cytometry/fluorescence microscopy represent technically straightforward methods for the detection and quantification of G6PD-deficient erythrocytes. Based on our results, we recommend their application as a first-line investigation to screen females who are prescribed an oxidant drug like primaquine or dapsone.

Metabolic profiling reveals alterations in the erythrocyte response to fava bean ingestion in G6PD-deficient mice.

BACKGROUND: Favism is an acute hemolytic syndrome caused by fava bean (FB) ingestion. The purpose of this study was to investigate the possible influences of FB on the metabonomic profile of erythrocytes in glucose-6-phosphate dehydrogenase (G6PD)-deficient (G6PDx) and wild-type (WT) mice. RESULTS: Ninety-two metabolites were identified in the comparison of the G6PDx and WT groups. Eighty-seven metabolites were identified in the erythrocytes of WT and G6PDx mice after FB ingestion. Thirty-eight metabolites were identified in the comparison of the FB-treated G6PDx and the FB-treated WT mouse groups. Among them, the number of glycerophospholipids (GPLs) and polyunsaturated fatty acids (PUFAs) changed significantly, which suggests that GPLs and PUFAs may be responsible for FB stress. CONCLUSION: This study demonstrates that G6PD deficiency might affect the metabonomic profile of erythrocytes in response to FB. © 2020 Society of Chemical Industry.

Epidemiology, evolutionary origin, and malaria-induced positive selection effects of G6PD-deficient alleles in Chinese populations.

BACKGROUND: Although glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common inherited disorder in the Chinese population, there is scarce evidence regarding the epidemiology, evolutionary origin, and malaria-induced positive selection effects of G6PD-deficient alleles in various Chinese ethnic populations. METHODS: We performed a large population-based screening (n = 15,690) to examine the impact of selection on human nucleotide diversity and to infer the evolutionary history of the most common deficiency alleles in Chinese populations. RESULTS: The frequencies of G6PD deficiency ranged from 0% to 11.6% in 12 Chinese ethnic populations. A frequency map based on geographic information showed that G6PD deficiency was highly correlated with historical malaria prevalence in China and was affected by altitude and latitude. The five most frequently occurring G6PD gene variants were NM_001042351.3:c.1376G>T, NM_001042351.3:c.1388G>A, NM_001042351.3:c.95A>G, NM_001042351.3:c.1311T>C, and NM_001042351.3:c.1024C>T, which were distributed with ethnic features. A pathogenic but rarely reported variant site (NM_001042351.3:c.448G>A) was identified in this study. Bioinformatic analysis revealed a strong and recent positive selection targeting the NM_001042351.3:c.1376G>T allele that originated in the past 3125 to 3750 years and another selection targeting the NM_001042351.3:c.1388G>A allele that originated in the past 5000 to 6000 years. Additionally, both alleles originated from a single ancestor. CONCLUSION: These results indicate that malaria has had a major impact on the Chinese genome since the introduction of rice agriculture.

A novel G6PD deleterious variant identified in three families with severe glucose-6-phosphate dehydrogenase deficiency.

BACKGROUND: Glucose-6-phosphate dehydrogenase deficiency (D-G6PD) is an X-linked recessive disorder resulted from deleterious variants in the housekeeping gene Glucose-6-phosphate 1-dehydrogenase (G6PD), causing impaired response to oxidizing agents. Screening for new variations of the gene helps with early diagnosis of D-G6PD resulting in a reduction of disease related complications and ultimately increased life expectancy of the patients. METHODS: One thousand five hundred sixty-five infants with pathological jaundice were screened for G6PD variants by Sanger sequencing all of the 13 exons, and the junctions of exons and introns of the G6PD gene. RESULTS: We detected G6PD variants in 439 (28.1%) of the 1565 infants with pathological jaundice. In total, 9 types of G6PD variants were identified in our cohort; and a novel G6PD missense variant c.1118 T > C, p.Phe373Ser in exon 9 of the G6PD gene was detected in three families. Infants with this novel variant showed decreased activity of G6PD, severe anemia, and pathological jaundice, consistent with Class I G6PD deleterious variants. Analysis of the resulting protein's structure revealed this novel variant affects G6PD protein stability, which could be responsible for the pathogenesis of D-G6PD in these patients. CONCLUSIONS: High rates of G6PD variants were detected in infants with pathological jaundice, and a novel Class I G6PD deleterious variants was identified in our cohort. Our data reveal that variant analysis is helpful for the diagnosis of D-G6PD in patients, and also for the expansion of the spectrum of known G6PD variants used for carrier detection and prenatal diagnosis.

Effects of Single and Double Mutants in Human Glucose-6-Phosphate Dehydrogenase Variants Present in the Mexican Population: Biochemical and Structural Analysis.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most frequent human enzymopathy, affecting over 400 million people globally. Worldwide, 217 mutations have been reported at the genetic level, and only 19 have been found in Mexico. The objective of this work was to contribute to the knowledge of the function and structure of three single natural variants (G6PD A+, G6PD San Luis Potosi, and G6PD Guadalajara) and a double mutant (G6PD Mount Sinai), each localized in a different region of the three-dimensional (3D) structure. In the functional characterization of the mutants, we observed a decrease in specific activity, protein expression and purification, catalytic efficiency, and substrate affinity in comparison with wild-type (WT) G6PD. Moreover, the analysis of the effect of all mutations on the structural stability showed that its presence increases denaturation and lability with temperature and it is more sensible to trypsin digestion protease and guanidine hydrochloride compared with WT G6PD. This could be explained by accelerated degradation of the variant enzymes due to reduced stability of the protein, as is shown in patients with G6PD deficiency.

The prevalence of glucose-6-phosphate dehydrogenase deficiency in the Cape Verdean population in the context of malaria elimination.

Cabo Verde aims to eliminate malaria by 2020. In the country, Plasmodium falciparum had been the main parasite responsible for indigenous cases and primaquine is the first line treatment of cases and for radical cure. However, the lack of knowledge of the national prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency may be one of the constraints to the malaria elimination process. Hence, this first study determines the prevalence of G6PD deficiency (G6PDd) in the archipelago. Blood samples were collected from patients who voluntarily agreed to participate in the study, in the health facilities of eight municipalities on four islands, tested with G6PD CareStart ™ deficiency Rapid Diagnosis Test (RDT). All subjects found to be G6PDd by RDT then underwent enzyme quantification by spectrophotometry. Descriptive statistics and inferences were done using SPSS 22.0 software. A total of 5.062 blood samples were collected, in majority from female patients (78.0%) and in Praia (35.6%). The RDT revealed the prevalence of G6PD deficiency in 2.5% (125/5062) of the general population, being higher in males (5.6%) than in females (1,6%). The highest G6PDd prevalence was recorded in São Filipe, Fogo, (5.4%), while in Boavista no case was detected. The G6PDd activity quantification shown a higher number of partially deficient and deficient males (respectively n = 26 and n = 22) compared to females (respectively n = 18 and n = 7), but more normal females (n = 35) than males (n = 11). According to the WHO classification, most of the G6PDd cases belongs to the class V (34.5%), while the Classes II and I were the less represented with respectively 5.8% and zero cases. This study in Cabo Verde determined the G6PDd prevalence in the population, relatively low compared to other African countries. Further studies are needed to characterize and genotyping the G6PD variants in the country.

Prevalence of UGT1A1 (TA)n promoter polymorphism in Panamanians neonates with G6PD deficiency.

A relationship between the polymorphism in promoter region of the UGT1A1 gene and the development of jaundice has been demonstrated recently. This polymorphism leads to 30% of normal rate transcription initiation of UGT1A1 gene, thus decreasing the bilirubin glucuronidation. The combination of the G6PD deficiency and polymorphism in neonates and adults may causepronounced hyperbilirubinaemias. The aim of this study was to analyse the variations in the UGT1A1 gene promoter in Panamanians neonates with G6PD deficiency and its association with neonatal jaundice (NJ). We identified five different genotypes of TA repeats, in 17 neonates (42.5%) the normal variant TA6/TA6 and in the other 57.5% of the subjects: TA7/TA7 (12.5%), TA6/TA7 (40%), TA6/TA8 (2.5%) and TA6/TA5 (2.5%). Additionally 75% of the 16 newborns that showed NJ had an abnormal variant in the promotersequence, although, there was no significant difference (P = 0.068). The risk of jaundice in neonates with TA7 variant was thrice higher in subjects than with other alleles (P = 0.093, CI: 0.81-11.67). The TA7 allele frequency in this study (0.325) was consistent with the global frequency and similar to Caucasians. The results proved that there is no significant relationship between promoter polymorphism in UGT1A1 and NJ in G6PD deficient Panamanian newborns. Further studies with a greater number of subjects would determine the exact relationship between marked NJ and UGT1A promoter variations.

The association between low glucose-6-phosphate dehydrogenase activity level and hepatitis B virus infection among pre-pregnant reproductive-age Chinese females.

The relationship between females with low glucose-6-phosphate dehydrogenase activity level (LG6PD) and HBV infection is unclear. We conducted a cross sectional study of 124 406 reproductive-age Chinese females who participated in the National Free Pre-conception Check-up Projects to investigate the risk of HBV infection among females with LG6PD and its effect on liver enzyme. Based on HBV serological test results, the participants were divided into the susceptible, immunized, and HBV infected groups. The multivariable-adjusted odds ratios (ORs) for HBV infection in LG6PD participants were 1.71 (95% confidence interval (CI): 1.45-2.01) and 1.41 (95% CI: 1.23-1.62), respectively with the susceptible and immunized participants as references, compared to those without LG6PD. Participants with HBV infection only and combined with HBV infection and LG6PD had 184% and 249% significantly higher risks of elevated alanine transaminase (ALT) (susceptible participants as reference). If the immunized participants were used as reference, significant higher odds of elevated ALT occurred (3.48 (95% CI: 3.18-3.80), 4.28 (95% CI: 2.92-6.28)). Thus, reproductive-age females with LG6PD had a higher prevalence of HBV infection, and LG6PD might exacerbate ALT elevation in HBV infected females. Our findings underscore the need to explore collaborative management approaches for these two diseases among reproductive-age females for maternal and child health.

Impact of glucose-6-phosphate dehydrogenase deficiency on dengue infection in Myanmar children.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency may affect the clinical presentation of dengue due to the altered redox state in immune cells. We aimed to determine the association between G6PD deficiency and severity of dengue infection in paediatric patients in Myanmar. A cross-sectional study was conducted among paediatric patients aged 2-13 years with dengue in Yankin Children Hospital, Myanmar. One hundred and ninety-six patients positive for dengue infection, as determined via PCR or ELISA, were enrolled. Dengue severity was determined according to the 2009 WHO classification guidelines. Spectrophotometric assays determined G6PD levels. The adjusted median G6PD value of males in the study population was used to define various cut-off points according to the WHO classification guidelines. G6PD genotyping for Mahidol, Kaiping and Mediterranean mutations was performed for 128 out of 196 samples by real-time multiplex PCR. 51 of 196 (26.0%) patients had severe dengue. The prevalence of G6PD phenotype deficiency (< 60% activity) in paediatric patients was 14.8% (29/196), specifically, 13.6% (14/103) in males and 16.2% (15/93) in females. Severe deficiency (< 10% activity) accounted for 7.1% (14/196) of our cohort, occurring 11.7% (12/103) in males and 2.2% (2/93) in females. Among 128 samples genotyped, the G6PD gene mutations were detected in 19.5% (25/128) of patients, with 20.3% (13/ 64) in males and 18.8% (12/64) in females. The G6PD Mahidol mutation was 96.0% (24/25) while the G6PD Kaiping mutation was 4.0% (1/25). Severe dengue was not associated with G6PD enzyme deficiency or presence of the G6PD gene mutation. Thus, no association between G6PD deficiency and dengue severity could be detected. Trial registration: The study was registered following the WHO International Clinical Trials Registry Platform (WHO-ICTRP) on Thai Clinical Trials Registry (TCTR) website, registration number # TCTR20180720001.

Analysis of Glucose-6-Phosphate Dehydrogenase Genetic Polymorphism in the Hakka Population in Southern China.

BACKGROUND In southern China, glucose-6-phosphate dehydrogenase (G6PD) deficiency is a significant health problem. The aim of this study was to investigate the molecular epidemiological characteristic of the G6PD gene among Chinese Hakka in southern Guangdong province. MATERIAL AND METHODS We screened 611 unrelated subjects for G6PD genetic polymorphism analyzed by a gene chip analysis for common Chinese G6PD mutations. G-6-PD enzyme activity was determined by use of the G-6-PD quantitative detection kit. RESULTS Seven mutation sites were detected from subjects in our study. G6PD Canton (c.1376 G→T)(33.06%), G6PD Kaiping (c.1388 G→A)(30.67%), and polymorphism (c.1311 C→T)(25.89%) account for 89.62% of mutations, followed by G6PD Gaohe (c.95 A→G)(5.97%), G6PD Chinese-5 (c.1024 C→T)(3.58%), G6PD Maewo (c.1360 C→T)(0.39%), and G6PD Viangchan (c.871G→A)(0.39%). CONCLUSIONS We studied the genetic polymorphisms and frequencies of G6PD gene in the Hakka population of Meizhou. Our results coincide with the results among the Chinese Jiangxi Hakka population. It was consistent with previous research reports on Chinese people. There were differences in the results of reports from some other Asian populations. Our results could be useful for future prevention and control of G6PD deficiency aimed at the Chinese Hakka population.

Glucose-6-Phosphate Dehydrogenase Deficiency is Associated with Cardiovascular Disease in U.S. Military Centers.

Glucose-6-phosphate dehydrogenase (G6PD) protects erythrocytes from oxidative stress and hemolysis; G6PD deficiency is the most prevalent enzymopathy. The United States military routinely performs tests to prevent exposing G6PD-deficient personnel to antimalarial drugs that might cause life-threatening hemolytic reactions. In addition, G6PD is a key determinant of vascular function, and its deficiency can lead to impaired nitric oxide production and greater vascular oxidant stress-precursors to atherosclerosis and cardiovascular disease. Using military medical records, we performed a retrospective, cross-sectional study to investigate whether deficient G6PD levels are associated with a higher prevalence of cardiovascular disease than are normal levels, and, if so, whether the relationship is independent of accepted cardiovascular risk factors. We analyzed the medical records of 737 individuals who had deficient G6PD levels and 16,601 who had normal levels. Everyone had been screened at U.S. military medical centers from August 2004 through December 2007. We evaluated our dependent variable (composite cardiovascular disease) at the individual level, and performed binary logistic regression of our independent variable (G6PD status) and control variables (modifiable cardiovascular risk factors). The adjusted odds ratio of 1.396 (95% CI, 1.044-1.867; P <0.05) indicated that G6PD-deficient individuals have 39.6% greater odds of developing cardiovascular disease than do those with normal levels. Early intervention may reduce the incidence of cardiovascular disease in military personnel and civilians who have deficient G6DP levels.

Hemolysis and Glucose-6-Phosphate Dehydrogenase Deficiency-Related Neonatal Hyperbilirubinemia.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common enzyme deficiency affecting more than 300 million individuals worldwide. Extreme neonatal hyperbilirubinemia, with its severe sequelae of bilirubin neurotoxicity and the potential of death, is the most devastating manifestation of G6PD deficiency. In a recent review of Favism, Luzzatto and Arese state that the pathophysiology of jaundice in G6PD-deficient neonates is different from that of favism, as there is little evidence of hemolysis in these infants. OBJECTIVES: To explore the role of hemolysis in neonatal hyperbilirubinemia associated with G6PD deficiency. METHODS: Previously published works including studies of endogenous production of carbon monoxide (CO), an index of heme catabolism, in hyperbilirubinemic G6PD-deficient neonates were reviewed to determine the role of hemolysis in this condition. RESULTS: Three studies demonstrated that endogenous CO production is elevated in G6PD-deficient neonates with extreme hyperbilirubinemia. CONCLUSIONS: Hemolysis is an important pathogenetic factor in G6PD deficiency-associated neonatal hyperbilirubinemia.

Prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency among malaria patients in Upper Myanmar.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) deficiency is one of the most common X-linked recessive hereditary disorders in the world. Primaquine (PQ) has been used for radical cure of P. vivax to prevent relapse. Recently, it is also used to reduce P. falciparum gametocyte carriage to block transmission. However, PQ metabolites oxidize hemoglobin and generate excessive reactive oxygen species which can trigger acute hemolytic anemia in malaria patients with inherited G6PD deficiency. METHODS: A total of 252 blood samples collected from malaria patients in Myanmar were used in this study. G6PD variant was analysed by a multiplex allele specific PCR kit, DiaPlexC™ G6PD Genotyping Kit [Asian type]. The accuracy of the multiplex allele specific PCR was confirmed by sequencing analysis. RESULTS: Prevalence and distribution of G6PD variants in 252 malaria patients in Myanmar were analysed. Six different types of G6PD allelic variants were identified in 50 (7 females and 43 males) malaria patients. The predominant variant was Mahidol (68%, 34/50), of which 91.2% (31/34) and 8.8% (3/34) were males and females, respectively. Other G6PD variants including Kaiping (18%, 9/50), Viangchan (6%, 3/50), Mediterranean (4%, 2/50), Union (2%, 1/50) and Canton (2%, 1/50) were also observed. CONCLUSIONS: Results of this study suggest that more concern for proper and safe use of PQ as a radical cure of malaria in Myanmar is needed by combining G6PD deficiency test before PQ prescription. Establishment of a follow-up system to monitor potential PQ toxicity in malaria patients who are given PQ is also required.

Glucose-6-phosphate dehydrogenase deficiency in internationally adopted children.

There are conflicting guidelines about screening of internationally adopted children for glucose-6-phosphate dehydrogenase (G6PD) deficiency, a common genetic disorder. In a multi-ethnic population of 2,169 internationally adopted children, we found that the prevalence of G6PD deficiency was 1.6% overall and 2.2% in males. Prevalence differed by country or region of origin, ranging from 0 to 13% overall and 0 to 22% in males. The prevalence in females was 1%. A diagnosis of G6PD deficiency informs the treatment of malaria and enables education and counseling to prevent morbidity and mortality from G6PD deficiency. Screening for G6PD deficiency should be strongly considered for internationally adopted children.