Incorporating genotyping to identify patients with G6PD deficiency

Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common X-linked enzyme disorder associated with hemolytic anemia after exposure to certain medications or foods. Activity testing is the gold standard for detecting G6PD deficiency; however, this test is affected by various hematologic parameters. Clinical G6PD genotyping is included in pharmacogenetic arrays and clinical sequencing and may be reconciled with activity results. Methods: Patients (n=1,391) enrolled on an institutional pharmacogenetic testing protocol underwent clinical G6PD genotyping for 164 G6PD variants. For the 446 patients with G6PD activity results, algorithms were designed to assign G6PD status, accounting for known interferences with the activity assay and for G6PD genotype results. We developed clinical decision support alerts to inform prescribers when high-risk medications were prescribed, warning of gene-drug interactions and recommending therapy alteration. Results: Of 1,391 patients with genotype, 1,334 (95.9%) patients were predicted to have normal G6PD activity, 30 (2.1%) were predicted to have variable G6PD activity, and 27 (2%) were predicted to have deficient G6PD activity. Of the 417 patients with a normal genotype and an activity result, 415 (99.5%) had a concordant normal G6PD phenotype. Of the 21 patients with a deficient genotype and an activity result, 18 (85.7%) had a concordant deficient activity result. Genotyping reassigned phenotype in 5 patients with discordant genotype and activity results: 3 switched from normal to deficient, and 2 switched from deficient to normal. Conclusion: G6PD activity and genotyping are two independent testing methods which can be used in conjunction to assign a more informed G6PD phenotype.

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PO 8609 PREVALENCE AND RISK FACTORS FOR GLUCOSE-6-PHOSPHATE DEHYDROGENASE (G6PD) DEFICIENCY IN TWO P. VIVAX MALARIA-ENDEMIC AREAS IN SUDAN

BMJ Global Health ◽

10.1136/bmjgh-2019-edc.164 ◽

2019 ◽

Vol 4 (Suppl 3) ◽

pp. A62.2-A62

Author(s):

Muzamil Mahdi Abdel Hamid ◽

Musab Albsheer ◽

Mohamed Muneer ◽

Lina Altinae ◽

Andrew A Lover

Keyword(s):

Risk Factors ◽

G6pd Deficiency ◽

Demographic Data ◽

Univariate Analysis ◽

G6pd Activity ◽

Radical Cure ◽

Major Health Problem ◽

Significant Difference ◽

Endemic Areas ◽

Glucose 6 Phosphate Dehydrogenase

BackgroundPlasmodium vivax malaria is a major health problem in Sudan and the parasite has become widely distributed in the recent years. The WHO recommends the use of primaquine as radical cure for liver dormant stage, the hypnozoite. However, prior its use, a test for Glucose-6-phosphate Dehydrogenase (G6PD) should be performed. The objective of the current study was to determine prevalence and risk factors for G6PD deficiency in two P. vivax malaria-endemic areas in Sudan.MethodsA cross-sectional study recruiting 557 subjects from two malaria-endemic areas in Sudan was conducted. Demographic data and blood samples were collected. G6PD activity was measured by spectrometry using SPINREACT enzymatic-UV kit.ResultsThe measured G6PD activities for both sites ranged from 0.6 to 37.7 U/g Hb, with a median value of 12.8 U/g Hb. There was a significant difference in enzyme activity by study site (p<0.001), but not by sex (p=0.91). Overall, across the two study sites, 22 (3.9%) is G6PDd (<30%). Prevalence of G6PDd (<30%) in Khartoum is 1.8% (4/230) compared to 4.8% (16/327) in New Hafla. In univariate analysis predictors of G6PDd were study site (odds ratio of G6PD activity <3.8, Khartoum relative to New Halfa=0.22 (95% CI: 0.08 to 0.66), p=0.006), and recent antibiotic use (OR=2.45 (95% CI: 1.1 to 5.5), p=0.027). In multivariate analysis, the only factor that was significant was the individual’s weight in kilograms, with an OR of 0.97 (95% CI 0.95 to 0.99, p=0.014).ConclusionG6PD deficiency is less prevalent among Sudanese population and this indicates that the use of primaquine for radical cure of P. vivax malaria is safe.

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A Tetrazolium-Linked Cytochemical Method for Estimation of Glucose-6-Phosphate Dehydrogenase Activity in Individual Erythrocytes: Applications in the Study of Heterozygotes for Glucose-6-Phosphate Dehydrogenase Deficiency

Blood ◽

10.1182/blood.v31.5.589.589 ◽

1968 ◽

Vol 31 (5) ◽

pp. 589-603 ◽

Cited By ~ 41

Author(s):

VIRGIL F. FAIRBANKS ◽

LINDA T. LAMPE

Keyword(s):

Dehydrogenase Activity ◽

G6pd Deficiency ◽

Dehydrogenase Deficiency ◽

G6pd Activity ◽

New Method ◽

Cytochemical Method ◽

Conventional Methods ◽

Glucose 6 Phosphate Dehydrogenase ◽

Individual Erythrocytes

Abstract A new method is described for the graded estimation of G6PD activity in individual erythrocytes. The method appears to offer some technical advantages over other methods. It requires reagents that are neither hazardous nor unstable and such equipment as might be found in the usual hematology laboratory. It appears to be more sensitive than conventional methods for identification of women heterozygous for G6PD deficiency and further substantiates the existence of erythrocyte mosaicism in such individuals.

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MEDITERRANEAN GLUCOSE 6-PHOSPHATE DEHYDROGENASE (G6PD) DEFICIENCY: A GENETIC DISORDER WITH COMPLE TE ABSENCE OF ERYTHROCYTE G6PD ACTIVITY

Biochemical Society Transactions ◽

10.1042/bst009272pc ◽

1981 ◽

Vol 9 (2) ◽

pp. 272P-272P

Author(s):

A. De Flora ◽

A. Morelli ◽

U. Benatti ◽

L. Lenzerini ◽

B. Sparatore ◽

...

Keyword(s):

G6pd Deficiency ◽

Genetic Disorder ◽

G6pd Activity ◽

Glucose 6 Phosphate Dehydrogenase

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Ex Vivo Study of Laban's Role in Decreasing Hemolysis Crisis in G6PD-Deficient Patients

Journal of Nutrition and Metabolism ◽

10.1155/2020/8034672 ◽

2020 ◽

Vol 2020 ◽

pp. 1-5 ◽

Cited By ~ 2

Author(s):

Wissam Zam ◽

Loay Belal

Keyword(s):

Human Blood ◽

G6pd Deficiency ◽

Ex Vivo ◽

Antioxidant Properties ◽

G6pd Activity ◽

Environmental Benefits ◽

Fermented Dairy Products ◽

Fava Beans ◽

Glucose 6 Phosphate Dehydrogenase ◽

Fermented Dairy

In spite of the vast nutritional and environmental benefits provided by fava bean (Vicia faba), the ingestion of vicine/convicine provokes an acute hemolytic anemia called favism in individuals with a glucose-6-phosphate dehydrogenase (G6PD) deficiency. The elimination of these glycosides is a goal that could be accomplished using different processing methods including bacteriological treatment. Laban as a good source of lactic acid bacteria was tested in an ex vivo assay on human blood samples in order to determine its capacity in decreasing the hemolysis crisis induced by the ingestion of fava beans. Results indicate a significant decrease in human blood cell hemolysis after the treatment of fava beans by Laban. This decrease in hemolysis was also correlated with the G6PD deficiency categorization. The highest hemolysis level (mean: 23.11 ± 0.76%) was observed in samples with G6PD activity between 10 and 30%, while the lowest hemolysis level (mean: 5.75 ± 0.64%) was observed in samples with G6PD activity more than 60%. This decrease was correlated with a high antioxidant capacity of Laban (51.61 ± 1.13% expressed by the percentage inhibition of DPPH radical). The counts of isolates from MRS and M17 culture plates were 6.75 ± 0.095 and 7.91 ± 0.061 log cfu ml–1, respectively. In conclusion, the synergy between the antioxidant properties of Laban and the possible decrease of vicine and convicine concentrations by lactobacillus found in the fermented dairy products could explain the ability of Laban to reduce the hemolysis crisis ex vivo.

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Diverse point mutations result in glucose-6-phosphate dehydrogenase (G6PD) polymorphism in Taiwan

Blood ◽

10.1182/blood.v79.8.2135.2135 ◽

1992 ◽

Vol 79 (8) ◽

pp. 2135-2140 ◽

Cited By ~ 38

Author(s):

TK Tang ◽

CS Huang ◽

MJ Huang ◽

KB Tam ◽

CH Yeh ◽

...

Keyword(s):

G6pd Deficiency ◽

Novel Mutation ◽

Simultaneous Detection ◽

Point Mutations ◽

Direct Proof ◽

G6pd Activity ◽

Nucleotide Position ◽

Digestion Method ◽

Chinese Populations ◽

Glucose 6 Phosphate Dehydrogenase

Abstract Glucose-6-PHOSPHATE dehydrogenase (G6PD; EC 1.1.1.49) deficiency is the most common human enzymopathy, affecting more than 200 million people worldwide. Although greater than 400 variants have been described based on clinical and biochemical criteria, little is known about the molecular basis of these G6PD deficiencies. Recently, the gene that encodes human G6PD has been cloned and sequenced, which enables us to examine directly the heterogeneity of G6PD at the DNA level. During the past 10 years, we examined the G6PD activity in 21,271 newborn Chinese infants (11,400 males and 9,871 females) and identified 314 (2.8%) males and 246 (2.5%) females having low G6PD activity. The G6PD gene from 10 randomly selected affected individuals and their relatives was polymerase chain reaction (PCR) amplified, subcloned, and sequenced. Our results indicate that at least four types of mutation are responsible for the G6PD polymorphism in Taiwan. The first type of mutation (487 G----A) was found in an affected Chinese with a G to A change at nucleotide 487, which results in a (163)Gly to Ser substitution. The second type of mutation (493 A----G) is a novel mutation that has not been reported in any other ethnic group and was identified in two affected Chinese. This mutation causes an A to G change at nucleotide position 493, producing an (165)Asn to Asp substitution. Interestingly, the 487 G----A and 493 A----G mutations create Alu I and Ava II recognition sites, respectively, which enabled us to rapidly detect these two mutations by PCR/restriction enzyme (RE) digestion method. The third mutation (1376 G----T) was found in four affected Chinese. This mutation causes a G to T change at nucleotide position 1376 that results in an (459)Arg to Leu substitution. The 1376 G----T mutation seems to be the dominant allele that causes G6PD deficiency in Taiwan. Finally, two affected Chinese were identified as having the fourth mutation (1388 G----A). This mutation causes a G to A change at nucleotide 1388 that produces an (463)Arg to His substitution. Our studies provide the direct proof of the genetic heterogeneity of G6PD deficiency in the Chinese populations of Taiwan and the PCR/RE digestion method is suitable for simultaneous detection of the 487 G----A and 493 A----G mutations.

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Diverse point mutations result in glucose-6-phosphate dehydrogenase (G6PD) polymorphism in Taiwan

Blood ◽

10.1182/blood.v79.8.2135.bloodjournal7982135 ◽

1992 ◽

Vol 79 (8) ◽

pp. 2135-2140

Author(s):

TK Tang ◽

CS Huang ◽

MJ Huang ◽

KB Tam ◽

CH Yeh ◽

...

Keyword(s):

G6pd Deficiency ◽

Novel Mutation ◽

Simultaneous Detection ◽

Point Mutations ◽

Direct Proof ◽

G6pd Activity ◽

Nucleotide Position ◽

Digestion Method ◽

Chinese Populations ◽

Glucose 6 Phosphate Dehydrogenase

Glucose-6-PHOSPHATE dehydrogenase (G6PD; EC 1.1.1.49) deficiency is the most common human enzymopathy, affecting more than 200 million people worldwide. Although greater than 400 variants have been described based on clinical and biochemical criteria, little is known about the molecular basis of these G6PD deficiencies. Recently, the gene that encodes human G6PD has been cloned and sequenced, which enables us to examine directly the heterogeneity of G6PD at the DNA level. During the past 10 years, we examined the G6PD activity in 21,271 newborn Chinese infants (11,400 males and 9,871 females) and identified 314 (2.8%) males and 246 (2.5%) females having low G6PD activity. The G6PD gene from 10 randomly selected affected individuals and their relatives was polymerase chain reaction (PCR) amplified, subcloned, and sequenced. Our results indicate that at least four types of mutation are responsible for the G6PD polymorphism in Taiwan. The first type of mutation (487 G----A) was found in an affected Chinese with a G to A change at nucleotide 487, which results in a (163)Gly to Ser substitution. The second type of mutation (493 A----G) is a novel mutation that has not been reported in any other ethnic group and was identified in two affected Chinese. This mutation causes an A to G change at nucleotide position 493, producing an (165)Asn to Asp substitution. Interestingly, the 487 G----A and 493 A----G mutations create Alu I and Ava II recognition sites, respectively, which enabled us to rapidly detect these two mutations by PCR/restriction enzyme (RE) digestion method. The third mutation (1376 G----T) was found in four affected Chinese. This mutation causes a G to T change at nucleotide position 1376 that results in an (459)Arg to Leu substitution. The 1376 G----T mutation seems to be the dominant allele that causes G6PD deficiency in Taiwan. Finally, two affected Chinese were identified as having the fourth mutation (1388 G----A). This mutation causes a G to A change at nucleotide 1388 that produces an (463)Arg to His substitution. Our studies provide the direct proof of the genetic heterogeneity of G6PD deficiency in the Chinese populations of Taiwan and the PCR/RE digestion method is suitable for simultaneous detection of the 487 G----A and 493 A----G mutations.

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Determining Quantitative Diagnostic Test Cut-off in G6PD Heterozygous Women for Tafenoquine Therapy

10.21203/rs.2.19598/v1 ◽

2019 ◽

Author(s):

Maria Swastika ◽

Alida R Harahap ◽

Lydia V Panggalo ◽

Sri Widia A Jusman ◽

Ari W Satyagraha

Keyword(s):

G6pd Deficiency ◽

Ex Vivo ◽

Strong Association ◽

G6pd Activity ◽

Main Function ◽

Ex Vivo Model ◽

Stress Markers ◽

Oxidative Markers ◽

Significant Difference ◽

Glucose 6 Phosphate Dehydrogenase

Abstract Background Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme disorder in the world. Its main function is to generate NADPH that is required for anti-oxidative pathway in the cells especially in red blood cells (RBC). G6PD deficiency is X-linked and thus subject to random X-chromosome inactivation in women giving them mosaic expression of G6PD activities in their individual cells. This phenomenon makes it difficult for diagnosis with the currently available G6PD qualitative diagnostic tests. With the rolling out of newly marketed anti-malarial drug tafenoquine which has a long half-life, screening for G6PD deficiency becomes a necessity where those with <70% G6PD activity cannot receive this drug. Thus, evidence for a quantitative cut-off for G6PD activity is needed to ensure safe drug administration.Methods RBC models were developed to analyze the effect of oxidant on RBC oxidative markers namely total glutathione (GSH) and malondialdehyde (MDA). G6PD activity was measured using quantitative assay from Trinity Biotech and was correlated with cytofluorometric assay. RBC from G6PD heterozygous women with different G6PD activities were also analyzed for comparison.Results There was a negative correlation between G6PD activity and CuCl concentration and a strong association between G6PD activities and proportion of G6PD normal RBC in CuCl-treated models and in ex vivo RBC. However, in terms of oxidative stress markers analyses, unlike the hypothesis where the lower G6PD activity, the higher MDA and the lower GSH level, our CuCl RBC model showed that in low G6PD activities (10-30%) cells, the MDA level is lower compared to the rest of the models (p<0.05). Our ex vivo model however were in line with the hypothesis, although the result was not significant (p=0.5). There was a significant difference between RBC with <60% and those with >80% G6PD activities in CuCl RBC model but not in ex vivo RBC (p=0.5). Genotyping heterozygous subjects showed G6PD Viangchan variant with 2.97 U/g Hb (33% activity) and 6.58 U/g Hb (74% activity).Conclusions The MDA and GSH analyses have pointed to the 60% G6PD activity cut-off. This provides an evidence of possible cut-off for tafenoquine administration in G6PD heterozygous women.

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Addressing the gender-knowledge gap in glucose-6-phosphate dehydrogenase deficiency: challenges and opportunities

International Health ◽

10.1093/inthealth/ihy060 ◽

2018 ◽

Vol 11 (1) ◽

pp. 7-14 ◽

Cited By ~ 12

Author(s):

Gonzalo J Domingo ◽

Nicole Advani ◽

Ari W Satyagraha ◽

Carol H Sibley ◽

Elizabeth Rowley ◽

...

Keyword(s):

G6pd Deficiency ◽

G6pd Activity ◽

Knowledge Gap ◽

Genetic Trait ◽

Serious Adverse Events ◽

Severe Deficiency ◽

Challenges And Opportunities ◽

Plasmodium Vivax Malaria ◽

Glucose 6 Phosphate Dehydrogenase ◽

Gender Knowledge

Abstract Glucose-6-phosphate dehyrdgoenase (G6PD) deficiency is a common X-linked genetic trait, with an associated enzyme phenotype, whereby males are either G6PD deficient or normal, but females exhibit a broader range of G6PD deficiencies, ranging from severe deficiency to normal. Heterozygous females typically have intermediate G6PD activity. G6PD deficiency has implications for the safe treatment for Plasmodium vivax malaria. Individuals with this deficiency are at greater risk of serious adverse events following treatment with the only curative class of anti-malarials, 8-aminoquinolines, such as primaquine. Quantitative diagnostic tests for G6PD deficiency are complex and require sophisticated laboratories. The commonly used qualitative tests, do not discriminate intermediate G6PD activities. This has resulted in poor understanding of the epidemiology of G6PD activity in females and its corresponding treatment ramifications. New simple-to-use quantitative tests, and a momentum to eliminate malaria, create an opportunity to address this knowledge gap. While this will require additional resources for clinical studies, adequate operational research, and appropriate pharmacovigilance, the health benefits from this investment go beyond the immediate intervention for which the G6PD status is first diagnosed.

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THE INFLUENCE OF HAEMOGLOBIN-S AND G6PD DEFICIENCY ON THE ACTIVITY OF THE 17β-HYDROXYSTEROID DEHYDROGENASE OF INTACT HUMAN ERYTHROCYTES

Acta Endocrinologica ◽

10.1530/acta.0.0750793 ◽

1974 ◽

Vol 75 (4) ◽

pp. 793-800

Author(s):

A. O. Sogbesan ◽

O. A. Dada ◽

B. Kwaku Adadevoh

Keyword(s):

Enzyme Activity ◽

Dehydrogenase Activity ◽

Sex Steroids ◽

G6pd Deficiency ◽

Incubation Medium ◽

Hydroxysteroid Dehydrogenase ◽

G6pd Activity ◽

Reverse Transformation ◽

Oxidative Transformation ◽

Haemoglobin S

ABSTRACT The 17β-hydroxysteroid dehydrogenase activity in intact erythrocytes of Nigerian patients, in particular with regard to haemoglobin genotypes and G6PD* activity was studied. The G6PD activity of the erythrocyte did not affect the oxidative transformation of testosterone to androstenedione and of oestradiol to oestrone. The reduction (reverse transformation) was inhibited in G6PD-deficient erythrocytes but this inhibition was offset by the addition of 0.025 m glucose to the incubation medium. The per cent oxidation transformation of testosterone was higher in Hb-AA than in Hb-SS erythrocytes. It is suggested that the differences may be a result of either lower enzyme activity in the Hb-SS erythrocytes or of differences in the uptake and possibly binding of sex steroids by intact Hb-SS and Hb-AA erythrocytes.

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Molecular Characterization of Glucose-6-Phosphate Dehydrogenase Deficiency in the Shenzhen Population

Human Heredity ◽

10.1159/000516808 ◽

2021 ◽

pp. 1-7

Author(s):

Jian Gao ◽

Sheng Lin ◽

Shiguo Chen ◽

Qunyan Wu ◽

Kaifeng Zheng ◽

...

Keyword(s):

G6pd Deficiency ◽

Amplification Refractory Mutation System ◽

Gene Variants ◽

Coding Region ◽

G6pd Gene ◽

Mutation System ◽

Hotspot Mutations ◽

Glucose 6 Phosphate Dehydrogenase ◽

Generation Sequencing

Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is caused by one or more mutations in the G6PD gene on chromosome X. This study aimed to characterize the G6PD gene variant distribution in Shenzhen of Guangdong province. Methods: A total of 33,562 individuals were selected at the hospital for retrospective analysis, of which 1,213 cases with enzymatic activity-confirmed G6PD deficiency were screened for G6PD gene variants. Amplification refractory mutation system PCR was first used to screen the 6 dominant mutants in the Chinese population (c.1376G>T, c.1388G>A, c.95A>G, c.1024C>T, c.392G>T, and c.871G>A). If the 6 hotspot variants were not found, next-generation sequencing was then performed. Finally, Sanger sequencing was used to verify all the mutations. Results: The incidence of G6PD deficiency in this study was 3.54%. A total of 26 kinds of mutants were found in the coding region, except for c.-8-624T>C, which was in the noncoding region. c.1376G>T and c.1388G>A, both located in exon 12, were the top 2 mutants, accounting for 68.43% of all individuals. The 6 hotspot mutations had a cumulative proportion of 94.02%. Conclusions: This study provided detailed characteristics of G6PD gene variants in Shenzhen, and the results would be valuable to enrich the knowledge of G6PD deficiency.

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