Glucose-6-phosphate Dehydrogenase Deficiency Research Articles

Exchange Transfusion Trends and Risk Factors for Extreme Neonatal Hyperbilirubinemia over 10 Years in Shiraz, Iran.

Exchange transfusion (ET) is an effective treatment for acute bilirubin encephalopathy and extreme neonatal hyperbilirubinemia (ENH). It can reduce mortality and morbidity. This study aimed to investigate the trends and risk factors of ENH requiring ET in hospitalized neonates in Iran. A retrospective analysis of medical records of neonates who underwent ET due to ENH was conducted from 2011 to 2021, in Shiraz, Iran. Clinical records were used to gather demographic and laboratory data. The quantitative data were expressed as mean±SD, and qualitative data was presented as frequency and percentage. P<0.05 was considered statistically significant. During the study, 377 ETs were performed for 329 patients. The annual rate of ET decreased by 71.2% during the study period. The most common risk factor of ENH was glucose-6-phosphate dehydrogenase (G6PD) deficiency (35%), followed by prematurity (13.06%), ABO hemolytic disease (7.6%), sepsis (6.4%), Rh hemolytic disease (6.08%), and minor blood group incompatibility (3.34%). In 28.52% of the cases, the cause of ENH was not identified. 17 (5.1%) neonates had acute bilirubin encephalopathy, of whom 6 (35.29%) had G6PD deficiency, 6 (35.29%) had ABO incompatibility, and 2 (11.76%) had Rh incompatibility. Although the rate of ET occurrence has decreased, it seems necessary to consider different risk factors and appropriate guidelines for early identification and management of neonates at risk of ENH should be developed. The findings of the study highlighted the important risk factors of ENH in southern Iran, allowing for the development of appropriate prevention strategies.

G6PD deficiency in childhood borderline tuberculoid leprosy: A rare case

G6PD deficiency in childhood borderline tuberculoid leprosy: A rare case

A prospective study on the causes of hyperbilirubinemia and its clinical markers in term and near-term newborns admitted to a tertiary care hospital in Patna, India

This study aimed to investigate the root causes, prognostic factors, and therapeutic strategies for neonatal hyperbilirubinemia among term and near-term infants admitted to the Neonatal Intensive Care Unit (NICU) at IGIMS, Patna. Furthermore, the research aimed to analyze the clinical progression of these infants throughout their NICU stay.Conducted within the NICU at IGIMS, Patna, Bihar, this study encompassed term and late preterm infants admitted with serum bilirubin levels exceeding 12 mg/dl. The primary focus was on identifying risk factors, etiological factors, and the clinical profile of these infants during their NICU tenure.The study examined birth weight distribution and concurrent medical conditions. Parameters included the initiation of phototherapy based on bilirubin levels and treatment methodologies. Out of the 210 infants studied, 27.14% and 47.62% weighed between 2001 and 2500 grams. The most prevalent causes were physiological (129 cases), fetal prematurity (30 cases), birth asphyxia (7 cases), and prolonged labor (18 cases). Idiopathic causes were observed in 28 instances, ABO incompatibility in 7 cases, and Rh incompatibility in 7 cases. G6PD deficiency was identified once. At the commencement of phototherapy, 19.52% had bilirubin levels between 12 and 15 mg/dl, 58.57% between 15.1 and 18 mg/dl, 11.91% above 20 mg/dl, and 10% between 18.1 and 20 mg/dl.Physiological causes emerged as the most frequent contributors to neonatal hyperbilirubinemia, followed by septicemia and idiopathic factors. Infrequent causes included blood group incompatibility. Phototherapy was established as a cost-effective and efficient method for reducing bilirubin levels in neonatal jaundice. Exchange transfusion proved to be a safe therapeutic measure in cases of severe hyperbilirubinemia. Blood group incompatibility was the main determinant requiring exchange transfusion.

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

BackgroundPlasmodium 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.MethodsFor 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.ResultsIn 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.ConclusionsIn 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.

Population pharmacokinetic modelling of primaquine exposures in lactating women and breastfed infants

Current guidelines advise against primaquine treatment for breastfeeding mothers to avoid the potential for haemolysis in infants with G6PD deficiency. To predict the haemolytic risk, the amount of drug received from the breast milk and the resulting infant drug exposure need to be characterised. Here, we develop a pharmacokinetic model to describe the drug concentrations in breastfeeding women using venous, capillary, and breast milk data. A mother-to-infant model is developed to mimic the infant feeding pattern and used to predict their drug exposures. Primaquine and carboxyprimaquine exposures in infants are <1% of the exposure in mothers. Therefore, even in infants with the most severe G6PD deficiency variants, it is highly unlikely that standard doses of primaquine (0.25-1 mg base/kg once daily given to the mother for 1-14 days) would cause significant haemolysis. After the neonatal period, primaquine should not be restricted for breastfeeding women (Clinical Trials Registration: NCT01780753).

Exploring Appropriate Reference Intervals and Clinical Decision Limits for Glucose-6-Phosphate Dehydrogenase Activity in Individuals From Guangzhou, China.

Quantitative detection of glucose-6-phosphate dehydrogenase (G6PD) is commonly done to screen for G6PD deficiency. However, current reference intervals (RIs) of G6PD are unsuitable for evaluating G6PD-activity levels with local populations or associating G6PD variants with hemolysis risk to aid clinical decision-making. We explored appropriate RIs and clinical decision limits (CDLs) for G6PD activity in individuals from Guangzhou, China. We enrolled 5,852 unrelated individuals between 2020 and 2022 and screened their samples in quantitative assays for G6PD activity. We conducted further investigations, including G6PD genotyping, thalassemia genotyping, follow-up analysis, and statistical analysis, for different groups. In Guangzhou, the RIs for the G6PD activities were 11.20-20.04 U/g Hb in male and 12.29-23.16 U/g Hb in female. The adjusted male median and normal male median (NMM) values were 15.47 U/g Hb and 15.51 U/g Hb, respectively. A threshold of 45% of the NMM could be used as a CDL to estimate the probability of G6PD variants. Our results revealed high hemolysis-risk CDLs (male: <10% of the NMM, female: <30% of the NMM), medium hemolysis-risk CDLs (male: 10%-45% of the NMM, female: 30%-79% of the NMM), and low hemolysis-risk CDLs (male: ≥ 45% of the NMM, female: ≥ 79% of the NMM). Collectively, our findings contribute to a more accurate evaluation of G6PD-activity levels within the local population and provide valuable insights for clinical decision-making. Specifically, identifying threshold values for G6PD variants and hemolysis risk enables improved prediction and management of G6PD deficiency, ultimately enhancing patient care and treatment outcomes.

Mice harboring a human Mediterranean G6PD gene variant causing G6PD deficiency have decreased B1b cells and atheroprotective IgM, and increased atherosclerosis.

Abstract Epidemiological studies suggest a role of glucose 6-phosphate dehydrogenase deficiency (G6PDd) in exacerbated atherosclerosis. To date, no studies have established a causal relationship between the two. We herein report the first direct evidence of G6PDd causing atherosclerosis and deficits in B cells. Mice harboring the human Mediterranean G6PDd variant (hG6PDMed-) or the nondeficient human G6PD allele (hG6PDND) were rendered hyperlipemic via PCSK9 AAV and 12 weeks of high fat diet (HFD). Sudan-IV en face staining revealed increased atherosclerosis in the G6PDd mice when normalized to non-HDL cholesterol (hG6PDND n=9, hG6PDMed- n=8, P=0.0339). Next, flow cytometry was used to identify alterations in immune cells involved in atherosclerosis and revealed reduced atheroprotective B1b cells (CD19+B220-IgM+CD5-) in the peritoneal cavity and spleen (hG6PDND n=9, hG6PDMed- n=8, P=0.0111 &amp; P=0.0207). B1b cells secrete atheroprotective IgM to oxidation-specific epitopes (IgMOSE), and thus ELISA was used to measure IgMOSE levels. Despite normal total IgM levels compared to non-G6PDd mice, G6PDd mice had reduced IgMOSE to CuOx-LDL and PC-BSA when normalized to total IgM at baseline (hG6PDND n=8, hG6PDMed- n=7, P=0.0289 &amp; P=0.0022) and at 2 weeks of HFD (hG6PDND n=9, hG6PDMed- n=6, P=0.0016 &amp; P=0.0028). Together, these data demonstrate that G6PDd worsens atherosclerosis and suggest that this effect may be partly mediated by associated deficits in B1b cells and IgMOSE.

A case report of acute oxidative haemolysis following medicinal plant ingestion in a patient with G6PD deficiency

A case report of acute oxidative haemolysis following medicinal plant ingestion in a patient with G6PD deficiency

Kernicterus secondary to henna application in a neonate with G6PD deficiency: A case report

Kernicterus secondary to henna application in a neonate with G6PD deficiency: A case report

Epidemiological and biological characteristics of G6PD deficiency in women in Tunisia

Epidemiological and biological characteristics of G6PD deficiency in women in Tunisia

Field evaluation of a novel semi-quantitative point-of-care diagnostic for G6PD deficiency in Indonesia.

The WHO recommends routine testing of G6PD activity to guide radical cure in patients with Plasmodium vivax malaria. Females may have intermediate G6PD enzyme activity and to date, only complex diagnostics are able to reliably identify them. The semi-quantitative G6PD diagnostic "One Step G6PD Test" (Humasis, RoK; "RDT") is a lateral flow assay that can distinguish deficient, intermediate, and normal G6PD status and offers a simpler diagnostic alternative. G6PD status of participants enrolled in Malinau and Nunukan Regencies and the capital Jakarta was assessed with the RDT, and G6PD activity was measured in duplicate by reference spectrophotometry. The adjusted male median (AMM) of the spectrophotometry measurements was defined as 100% activity; 70% and 30% of the AMM were defined as thresholds for intermediate and deficient G6PD status, respectively. Results were compared to those derived from spectrophotometry at the clinically relevant G6PD activity thresholds of 30% and 70%. Of the 161 participants enrolled, 10 (6.2%) were G6PD deficient and 12 (7.5%) had intermediate G6PD activity by spectrophotometry. At the 30% threshold, the sensitivity of the RDT was 10.0% (95%CI: 0.3-44.5%) with a specificity of 99.3% (95%CI: 96.4-100.0%); the positive predictive value was 50.0% (95%CI: 1.3-98.7%) and the negative predictive value 94.3% (95%CI: 89.5-97.4%). The corresponding figures at the 70% threshold were 22.7% (95%CI: 7.8-45.4%), 100.0% (95%CI: 97.4-100.0%), 100.0% (95%CI: 47.8-100.0%) and 89.1% (95%CI: 83.1-93.5%), respectively. While there is a dire need for an easy-to-use, economical, semi-quantitative diagnostic for the point of care, the observed performance of the "One Step G6PD Test" in its current form was insufficient to guide antimalarial treatment.

198 Activated PI3Kδ Syndrome (APDS) associated with G6PD deficiency and reaction to BCG

198 Activated PI3Kδ Syndrome (APDS) associated with G6PD deficiency and reaction to BCG

Genetic Analysis of Two Novel GPI Variants Disrupting H Bonds and Localization Characteristics of 55 Gene Variants Associated with Glucose-6-phosphate Isomerase Deficiency.

Glucose-6-phosphate isomerase (GPI) deficiency is a rare hereditary nonspherocytic hemolytic anemia caused by GPI gene variants. This disorder exhibits wide heterogeneity in its clinical manifestations and molecular characteristics, often posing challenges for precise diagnoses using conventional methods. To this end, this study aimed to identify the novel variants responsible for GPI deficiency in a Chinese family. The clinical manifestations of the patient were summarized and analyzed for GPI deficiency phenotype diagnosis. Novel compound heterozygous variants of the GPI gene, c.174C>A (p.Asn58Lys) and c.1538G>T (p.Trp513Leu), were identified using whole-exome and Sanger sequencing. The AlphaFold program and Chimera software were used to analyze the effects of compound heterozygous variants on GPI structure. By characterizing 53 GPI missense/nonsense variants from previous literature and two novel missense variants identified in this study, we found that most variants were located in exons 3, 4, 12, and 18, with a few localized in exons 8, 9, and 14. This study identified novel compound heterozygous variants associated with GPI deficiency. These pathogenic variants disrupt hydrogen bonds formed by highly conserved GPI amino acids. Early family-based sequencing analyses, especially for patients with congenital anemia, can help increase diagnostic accuracy for GPI deficiency, improve child healthcare, and enable genetic counseling.

The association between glucose 6-phosphate dehydrogenase (G6PD) deficiency and attention deficit/hyperactivity disorder (ADHD)

IntroductionGlucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked genetic enzymopathy that impacts 4.9% of the population, with greater prevalence among Mediterranean, East Asian, and African populations. G6PD deficiency results in levels of nicotinamide-adenine dinucleotide phosphate (NADPH) and glutathione (GSH) that are insufficient for maintaining the balance of oxidation-reduction in the body. This results in elevated production of reactive oxygen species (ROS), oxidative stress on proteins and lipids, damage to DNA, and potential activation of chemokine and cytokine pathways by astrocytes and microglia. We propose that these direct and indirect effects of G6PD deficiency are associated with development of ADHD.ObjectivesThis study investigated the association between G6PD deficiency and Attention Deficit/Hyperactivity Disorder (ADHD).MethodsThe study involved 7,473 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. Clinical characteristics were analyzed using Fisher’s Exact Tests for categorical variables and Mann-Whitney U tests for continuous variables.ResultsThe average age of patients was 29.2 ± 22.3 years, with 68.7% being male. The mean follow-up duration was 14.3 ± 6.2 years. Individuals with G6PD deficiency showed a significant 16% higher risk of being diagnosed with ADHD (Odds Ratio (OR) = 1.16 [95% CI, 1.08-1.25], p &lt; 0.001) on follow up. Furthermore, G6PD deficiency was associated with a 30% greater likelihood of seeking care from adult neurologists (OR = 1.30 [95% CI, 1.22-1.38], p &lt; 0.001) and a 12% higher probability of 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 methylphenidate class drugs (OR = 1.17 [95% CI, 1.08, 1.27], p &lt; 0.001), and use of amphetamines elevated by 16% (OR = 1.16 [95% CI, 1.03, 1.37], p = 0.047).ConclusionsThis study establishes a significant association between G6PD deficiency and an increased risk of ADHD diagnoses. These findings suggest potential opportunities for the development of culturally sensitive interventions.Disclosure of InterestB. Krone Consultant of: HIPPO T&amp;C, Signant Health, J. Newcorn: None Declared, I. Manor: None Declared, E. Merzon: None Declared

Association between G6PD deficiency and schizophrenia A case report

IntroductionG6PD is essential for the production of NADPH, which is a cofactor for many enzymes involved in antioxidant defense and neurotransmitter synthesis. A deficiency in this enzyme could lead to increased oxidative stress, impaired neurotransmitter and immune function. The latter have been implicated in the pathophysiology of schizophrenia.ObjectivesThe present case is presented to underscore the infrequent and uncharacteristic manifestation of this condition, in the context of clinical symptoms and the trajectory of evolution of schizophrenia when associated with G6PD Deficiency. Moreover, it sheds light on the challenges clinicians encounter in the management of such cases.MethodsA case report of a patient who was admitted to the Psychiatry Department (“Ibn Omrane”) of Razi Hospital”.ResultsMr. M.T is a 26 year-old unmarried man. He comes from a non-consanguineous marriage and has an educational level of a bachelor’s degree plus three additional years of study. He has a significant family medical history. His maternal uncle is under treatment for a chronic psychotic disorder. He has a personal history of G6PD deficiency and no specific habits to note. At the age of 24, he insidiously developed anxiety with incoherent statements of persecution accompanied by behavioral manifestations leading to mistrust and social isolation. He discontinued his studies for a year and began verbalizing suicidal thoughts accompanied by self-harm behaviors.The family sought help from a psychiatrist who prescribed 5 mg of olanzapine, which was covertly administered to the patient.At the age of 28, after a suicide attempt, he was involuntarily admitted to Razi Hospital. The clinical presentation was dominated by disorganization, with a partial response to treatment.ConclusionsMore research is needed to confirm the association between G6PD deficiency and schizophrenia and to determine the underlying mechanisms. Larger studies with well-defined populations and methodologies are needed. It is also important to study the interaction between G6PD deficiency and other genetic and environmental factors that contribute to schizophrenia.Disclosure of InterestNone Declared

Hemolytic Anemia Due to Glucose-6-Phospate Dehydrogenase Deficiency in Neonate

Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme in erythrocytes that functions to maintain glycolysis, form an erythrocyte membrane, and protect hemoglobin from oxidative denaturation. Clinical manifestations of anemia and severe jaundice are risk factors for acute hyperbilirubinemia encephalopathy, which can progress to kernicterus. G6PD deficiency is X-linked. The incidence is most common in males with an incidence in Indonesia of 1-14%. A 3-day-old male baby appeared yellowish and had a history of being pale since 1 day of age. There was a history of phototherapy and packed red blood cell transfusion from a previous hospital. The baby was born via caesarean section, term baby, with a birth weight of 2700 grams. The Physical examination revealed Kramer V, tachypnea, but no hepatosplenomegaly. A previous laboratory examination at AM Hospital showed total bilirubin of 23.3 mg/dL, indirect bilirubin 23 mg/dL, and pre-transfusion hemoglobin 9.8 g/dL. Chest X-rays revealed grade I–II hyaline membrane disease. Meanwhile, the laboratory test results at the Dr Wahidin Sudirohusodo Hospital showed a total bilirubin of 38.5 mg/dL, indirect bilirubin 37.17 mg/dL, reticulocytes 9.95%, hemoglobin 11.8 g/dL, CRP 5.2 mg/L, Procalcitonin 0.5 ng/mL, and a negative Coombs test. The peripheral blood smear showed fragmented cells of erythrocytes. The G6PD level was 17.2 U/dL (reference value &gt;20.5 U/dL). The patient received low-flow oxygenation, antibiotics, and 72 hours of intensive phototherapy. On the 7th day of treatment, the condition improved, and the baby was discharged. Therefore, Rapid diagnosis and treatment of G6PD deficiency are important to prevent other potential complication such as acute hyperbilirubinemia encephalopathy.

Newborn screening in Colombia: The experience of a private program in 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.

Prevalence of common autosomal recessive mutation carriers in women in the Southern Vietnam following the application of expanded carrier screening

The common autosomal recessive (AR) mutation carrier is still unknown in Vietnam. This study aims to identify the most common AR gene mutation carriers in women of reproductive age to build a Vietnamese-specific carrier screening panel for AR and X-linked disorders in the preconception and prenatal healthcare program. A cross-sectional study was conducted at University Medical Center–Branch 2 in Ho Chi Minh City from December 1st, 2020, to June 30th, 2023. 338 women have consented to take a 5 mL blood test to identify 540 recessive genes. The carrier screening panel was designed based on the American College of Medical Genetics and Genomics (ACMG)-recommended genes and suggestions from 104 clinical experts in Vietnam. Obstetricians and genetic experts counseled all positive testing results to discuss the possibility of recessive diseases in their offspring. The most common recessive disorders were defined at a prevalence of 1 in 60 or greater, and those were added to a Vietnamese-specific carrier screening panel. 338 non-pregnant and pregnant women underwent the expanded carrier screening (ECS). The carrier frequency was 63.6%, in which 215 women carried at least one AR gene mutation. GJB2 hearing impairment was identified as the most common chronic condition (1 in 5). The second most common AR disorder was beta-thalassemia (1 in 16), followed by cystic fibrosis (1 in 23), G6PD deficiency (1 in 28), Wilson’s disease (1 in 31), Usher’s syndrome (1 in 31), and glycogen storage disease (1 in 56). Seven common recessive genes were added in ethnic-based carrier screening. Women in the South of Vietnam have been carried for many recessive conditions at high frequency, such as hearing impairment, genetic anemia, and cystic fibrosis. It is necessary to implement a preconception and prenatal screening program by using seven widely popular AR genes in a Vietnamese-specific carrier screening panel to reduce the burden related to AR and X-linked disorders.

Glucose phosphate isomerase deficiency demasked by whole-genome sequencing: a case report

BackgroundGlucose-6-phosphate isomerase deficiency is a rare genetic disorder causing hereditary nonspherocytic hemolytic anemia. It is the second most common glycolytic enzymopathy in red blood cells. About 90 cases are reported worldwide, with symptoms including chronic hemolytic anemia, jaundice, splenomegaly, gallstones, cholecystitis, and in severe cases, neurological impairments, hydrops fetalis, and neonatal death.Case presentationThis paper details the case of the first Danish patient diagnosed with glucose-6-phosphate isomerase deficiency. The patient, a 27-year-old white female, suffered from lifelong anemia of unknown origin for decades. Diagnosis was established through whole-genome sequencing, which identified two GPI missense variants: the previously documented variant p.(Thr224Met) and a newly discovered variant p.(Tyr341Cys). The pathogenicity of these variants was verified enzymatically.ConclusionsWhole-genome sequencing stands as a potent tool for identifying hereditary anemias, ensuring optimal management strategies.

Quantifying the effect of glucose 6-phosphate dehydrogenase deficiency on glycated hemoglobin values in children and adolescents with type 1 diabetes

The primary objectives of the study were (a) to confirm that glucose 6-phosphate dehydrogenase (G6PD) deficiency affects HbA1c values in a sample of children and adolescents with type 1 diabetes (T1D) and (b) to quantify this effect so that a correction can be applied to the HbA1c values found in current clinical practice. The following data were collected: age, sex, G6PD, number of daily capillary blood glucose measurements, 90-day average blood glucose levels prior to the study, HbA1c, and glycated hemoglobin estimated (eA1c) obtained from blood glucose levels. Patients were divided into three groups based on G6PD values: deficient, intermediate, and nondeficient. In each group, a comparison between the average eA1C and HbA1c values was performed. Then, the difference between the eA1c and HbA1c values of each patient and the mean of the differences (MD) of all patients was calculated within the three groups. Finally, a comparison of the MD values between groups was performed. Seventy-four subjects with T1D were studied. Based on the G6PD value, 33 subjects were deficient, 8 were intermediate, and 33 subjects were nondeficient. In deficient patients, the eA1c values were significantly higher than the HbA1c values. In the other two groups, however, there were no differences. The MD values between the three groups were significantly different. In deficient patients, MD values were higher than those in intermediate and in nondeficient patients. No difference was found between intermediate and nondeficient subjects. Our study confirms that G6PD deficiency affects HbA1c values in children and adolescents with T1D, both in deficient subjects and, to a much lesser extent, in intermediate subjects. In deficient subjects, there is an average reduction in HbA1c attributable to enzyme deficiency of 1.3% (14 mmol/mol) and in intermediate subjects of 0.3% (3 mmol/mol).