The gene spectrum of glucose-6-phosphate dehydrogenase (G6PD) deficiency in Guangdong province, China

Integrated Phenotypic and Genotypic Approaches for Accurate Diagnosis of G6PD Deficiency: Implications for Drug Safety in Thailand

Glucose-6-phosphate dehydrogenase (G6PD) deficiency holds critical health concerns, particularly due to its association with drug-induced hemolysis triggered by medications such as antimalarials. This condition poses significant risks in malaria-endemic regions where the prevalence and genetic diversity of G6PD deficiency further complicate management. Providing accurate and reliable G6PD status is vital to ensuring safe treatment, reducing complications, and improving healthcare outcomes in these populations. This study evaluated the integration of phenotypic and genotypic diagnostic methods for identifying G6PD deficiency in 2953 participants in Thailand. Using the water-soluble tetrazolium salts enzymatic assay and multiplex high-resolution melting analysis, the study revealed an overall prevalence of 3.93%, with 7.19% in males and 1.83% in females. A total of 38 distinct G6PD genotypes were identified, and zygosity was determined, highlighting significant genetic diversity, including previously unreported mutations as identified by sequencing. Hemizygous males, homozygous females, and approximately 50% of heterozygous females with missense mutations exhibited deficient or intermediate phenotypes. However, 40% of females carrying G6PD missense mutations showed a normal phenotype in quantitative phenotypic testing. The findings highlight the need for accurate G6PD diagnosis to improve drug safety and efficacy, particularly for vulnerable individuals such as heterozygous females, who are at risk of hemolysis. The cost-effective, high-throughput methods demonstrated here are suitable for large-scale screening, making them especially valuable in resource-limited settings. To maximize their impact, integrating both phenotypic and genotypic approaches into national healthcare policies and malaria programs is essential. By ensuring equitable access to reliable G6PD testing, these findings support malaria elimination efforts and address broader healthcare challenges, ultimately reducing preventable morbidity and mortality associated with G6PD deficiency.

Regional patterns of genetic variants in expanded carrier screening: a next-generation sequencing pilot study in Fujian Province, China

Background

This pilot study aimed to characterize the regional distribution of genetic variants associated with autosomal recessive and X-linked recessive (AR/XLR) conditions in Fujian Province, Southeast China, to inform the development of targeted carrier screening programs.

Methods

An expanded carrier screening (ECS) panel utilizing next-generation sequencing (NGS) technology was designed to analyze 332 genes associated with 343 AR/XLR conditions. The panel was applied to 440 samples obtained from individuals in Fujian Province. Single nucleotide variants and copy number variations (CNVs) were identified and analyzed using a multidimensional approach that incorporated demographic characteristics, carrier frequencies, and the genetic burden of AR/XLR diseases.

Results

A total of 511 variants were detected among the 440 participants, including 43 CNVs (8.41%), affecting 133 genes associated with 123 conditions. The mean number of pathogenic or likely pathogenic variants per sample was 1.16. The highest genetic burden was observed in couples seeking medically assisted reproduction (MAR group), who had histories of fetal loss, second- or third-trimester abnormalities, or postnatal abnormalities. In clinical settings, the percentage of at-risk couples (ARCs) was 6.36% (n = 14), involving seven conditions, with no statistically significant difference in ARC incidence between couples undergoing genetic screening (GS group) and the MAR group. The cumulative carrier rate for 28 genes was ≥1/100. Recurrent variants in GAA, GALT, CYP1B1, and MEFV were identified, exhibiting distinct regional patterns compared to previously reported variants in the Han Chinese population.

Conclusion

NGS-based ECS demonstrates significant potential for assessing the genetic burden of AR/XLR conditions and identifying ARCs in Fujian Province. However, before integrating ECS into regional public health initiatives, the development of a region-specific, curated disease panel is necessary to optimize screening efficacy and clinical utility.

Improved genetic screening with zygosity detection through multiplex high-resolution melting curve analysis and biochemical characterisation for G6PD deficiency

Accurate diagnosis of glucose-6-phosphate dehydrogenase (G6PD) deficiency is crucial for relapse malaria treatment using 8-aminoquinolines (primaquine and tafenoquine), which can trigger haemolytic anaemia in G6PD-deficient individuals. This is particularly important in regions where the prevalence of G6PD deficiency exceeds 3%-5%, including Southeast Asia and Thailand. While quantitative phenotypic tests can identify women with intermediate activity who may be at risk, they cannot unambiguously identify heterozygous females who require appropriate counselling. This study aimed to develop a genetic test for G6PD deficiency using high-resolution melting curve analysis, which enables zygosity identification of 15 G6PD alleles. In 557 samples collected from four locations in Thailand, the prevalence of G6PD deficiency based on indirect enzyme assay was 6.10%, with 8.08% exhibiting intermediate deficiency. The developed high-resolution melting assays demonstrated excellent performance, achieving 100% sensitivity and specificity in detecting G6PD alleles compared with Sanger sequencing. Genotypic variations were observed across four geographic locations, with the combination of c.1311C>T and c.1365-13T>C being the most common genotype. Compound mutations, notably G6PD Viangchan (c.871G>A, c.1311C>T and c.1365-13T>C), accounted for 15.26% of detected mutations. The high-resolution melting assays also identified the double mutation G6PD Chinese-4 + Canton and G6PD Radlowo, a variant found for the first time in Thailand. Biochemical and structural characterisation revealed that these variants significantly reduced catalytic activity by destabilising protein structure, particularly in the case of the Radlowo mutation. The refinement of these high-resolution melting assays presents a highly accurate and high-throughput platform that can improve patient care by enabling precise diagnosis, supporting genetic counselling and guiding public health efforts to manage G6PD deficiency-especially crucial in malaria-endemic regions where 8-aminoquinoline therapies pose a risk to deficient individuals.

The medium-fluorescence reticulocyte ratio is an independent predictor of G6PD deficiency neonates

OBJECTIVE

G6PD deficiency is a potentially life-threatening condition in neonates presenting with hyperbilirubinemia. This study aims to identify clinical and laboratory predictors of G6PD deficiency in neonates presenting with hyperbilirubinemia.

METHODS

This was a retrospective study of 227 term neonates admitted to Heyuan People's Hospital from January 2019 to October 2023. Hematological parameters and bilirubin were compared between those with G6PD deficiency and those with normal G6PD.

RESULTS

Term neonates with G6PD deficiency had higher levels of total bilirubin, indirect bilirubin, mean corpuscular volume, mean corpuscular hemoglobin, immature reticulocyte fraction, high-fluorescence reticulocyte ratio, medium-fluorescence reticulocyte ratio, and content of reticulocytes than those with normal G6PD, but lower levels of red blood cells, hemoglobin, hematocrit, and low-fluorescence reticulocyte ratio. Medium-fluorescence ratios (OR = 1.291, P = 0.028) independently predicted G6PD deficiency in neonates. The optimal cut-off value for medium-fluorescence ratios was > 18.55%. The area under the curve for diagnosing G6PD deficiency was 0.924 (95% confidence interval: 0.886-0.962, P < 0.0001), with a sensitivity of 82.6% and specificity of 86.2%.

CONCLUSION

MFR emerged as a potentially valuable predictor for G6PD deficiency in neonates.

Screening, genotyping and haematological analysis of glucose-6-phosphate dehydrogenase deficiency in the blood donors of Wuxi City, China

BACKGROUND AND OBJECTIVES

To investigate the prevalence, genotype and haematological characteristics of glucose-6-phosphate dehydrogenase (G6PD) deficiency in the blood donor population of Wuxi area (Jiangsu Province, China) and to assess the impact of their red blood cell (RBC) units on clinical transfusion.

MATERIALS AND METHODS

We conducted genotyping and large-scale screening for G6PD enzyme activity in the blood donors of Wuxi City. In addition, we assessed the haematological parameters of G6PD-deficient and non-deficient blood donors, and investigated the adverse transfusion reactions in patients transfused with G6PD-deficient blood.

RESULTS

We investigated 17,113 blood donors, among whom 44 (0.26%) were tested positive for G6PD deficiency. We identified 40 G6PD gene variants, among which c.1388G>A, c.1376G>T, c.1024C>T and c.95A>G were common. In addition, we identified two novel G6PD gene variants, c.1312G>A and c.1316G>A. The G6PD-deficient and non-deficient blood samples showed a significant difference in the RBC, mean corpuscular volume (MCV), mean corpuscular Hb (MCH), RBC distribution width, total bilirubin (TBIL), direct bilirubin (DBIL) and indirect bilirubin (IBIL) values. However, the two samples showed no significant difference in the haemolysis rate at the end of the storage period. Finally, transfusion with G6PD-deficient RBC units did not lead to any adverse transfusion reactions.

CONCLUSION

The positive rate of G6PD deficiency in the blood donor population of Wuxi City is 0.26%, and the genetic variants identified in this population are consistent with the common genetic variants observed in the Chinese population. Blood centres can establish a database on G6PD-deficient blood donors and mark their RBC units to avoid their use for special clinical patients.

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

Introduction

Glucose-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.

Methods

This 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.

Results

Of 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.

Discussion

To 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.

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

BACKGROUND

It was hypothesized that glucose-6-phosphate dehydrogenase (G6PD) deficiency confers a protective effect against malaria infection, however, safety concerns have been raised regarding haemolytic toxicity caused by radical cure with 8-aminoquinolines in G6PD-deficient individuals. Malaria elimination and control are also complicated by the high prevalence of G6PD deficiency in malaria-endemic areas. Hence, accurate identification of G6PD deficiency is required to identify those who are eligible for malaria treatment using 8-aminoquinolines.

METHODS

The prevalence of G6PD deficiency among 408 Thai participants diagnosed with malaria by microscopy (71), and malaria-negative controls (337), was assessed using a phenotypic test based on water-soluble tetrazolium salts. High-resolution melting (HRM) curve analysis was developed from a previous study to enable the detection of 15 common missense, synonymous and intronic G6PD mutations in Asian populations. The identified mutations were subjected to biochemical and structural characterisation to understand the molecular mechanisms underlying enzyme deficiency.

RESULTS

Based on phenotypic testing, the prevalence of G6PD deficiency (< 30% activity) was 6.13% (25/408) and intermediate deficiency (30-70% activity) was found in 15.20% (62/408) of participants. Several G6PD genotypes with newly discovered double missense variants were identified by HRM assays, including G6PD Gaohe + Viangchan, G6PD Valladolid + Viangchan and G6PD Canton + Viangchan. A significantly high frequency of synonymous (c.1311C>T) and intronic (c.1365-13T>C and c.486-34delT) mutations was detected with intermediate to normal enzyme activity. The double missense mutations were less catalytically active than their corresponding single missense mutations, resulting in severe enzyme deficiency. While the mutations had a minor effect on binding affinity, structural instability was a key contributor to the enzyme deficiency observed in G6PD-deficient individuals.

CONCLUSIONS

With varying degrees of enzyme deficiency, G6PD genotyping can be used as a complement to phenotypic screening to identify those who are eligible for 8-aminoquinolines. The information gained from this study could be useful for management and treatment of malaria, as well as for the prevention of unanticipated reactions to certain medications and foods in the studied population.

Molecular epidemiological investigation of G6PD deficiency in Yangjiang region, western Guangdong province

Objectives: The prevalence of G6PD deficiency has not been reported in Yangjiang, a western city in Guangdong province. This study aims to investigate the molecular characteristics of G6PD deficiency in this region. Methods: Blood samples were collected from adults at a local hospital to screen for G6PD deficiency. The deficient samples were subjected to further analysis using PCR and reverse dot blot to determine the specific G6PD variants. Results: Among the 3314 male subjects, 250 cases of G6PD deficiency were found using the G6PD enzyme quantitative assay, resulting in a prevalence of 7.54% (250/3314) in the Yangjiang region. The prevalence of G6PD deficiency in females was 3.42% (176/5145). Out of the 268 cases of G6PD deficiency tested for G6PD mutations, reverse dot blot identified 20 different G6PD variants. The most common G6PD variant was c.1388G>A (81/268), followed by c.1376G>T (48/268), c.95A>G (32/268), c.1024C>T (9/268), c.392G>T (7/268), and c.871G>A/c.1311C>T (6/268). It was observed that c.871G>A was always linked to the polymorphism of c.1311C>T in this population. Conclusion: This investigation into G6PD deficiency in this area is expected to significantly improve our understanding of the prevalence and molecular characterization of this condition.

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

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

Etiology analysis and G6PD deficiency for term infants with jaundice in Yangjiang of western Guangdong

OBJECTIVE

Glucose 6-phosphate dehydrogenase (G6PD) deficiency increases the risk of neonatal hyperbilirubinemia. The aim of this study is to evaluate the risk factors associated with hyperbilirubinemia in infants from the western part of Guangdong Province, and to assess the contribution of G6PD deficiency to neonatal jaundice.

METHODS

The term infants with neonatal hyperbilirubinemia in People's Hospital of Yangjiang from June 2018 to July 2022 were recruited for the retrospective analysis. All the infants underwent quantitative detection of the G6PD enzyme. The etiology was determined through laboratory tests and clinical manifestations.

RESULTS

Out of 1,119 term infants, 435 cases presented with jaundice. For the etiology analysis, infection was responsible for 16.09% (70/435), G6PD deficiency accounted for 9.66% (42/435), of which 3 were complicated with acute bilirubin encephalopathy), bleeding accounted for 8.05% (35/435), hemolytic diseases accounted for 3.45% (15/435), and breast milk jaundice accounted for 2.53% (11/435). One case (0.23%) was attributed to congenital hypothyroidism, multiple etiologies accounted for 22.3% (97/435), and 35.63% (155/435) were of unknown etiology. Of the jaundiced infants, 19.54% (85/435) had G6PD deficiency, while only 10.23% (70/684) of non-jaundiced infants had G6PD deficiency; this difference was found to be statistically significant (P < 0.001). Furthermore, the hemoglobin levels in the jaundiced infants with G6PD deficiency (146.85 ± 24.88 g/L) were lower than those without G6PD deficiency (156.30 ± 22.07 g/L) (P = 0.001). 65 jaundiced infants with G6PD deficiency underwent G6PD mutation testing, and six different genotypes were identified, including c.95A > G, c.392G > T, c.1024C > T, c.1311C > T, c.1376G > T, c.1388G > A, c.871G > A/c.1311C > T, c.392G > T/c.1388G > A, and c.1376G > T/c.1311C > T.65iciency.

CONCLUSION

In newborns in Yangjiang, G6PD deficiency, infection, and neonatal hemolytic disease were identified as the main causes of hyperbilirubinemia and acute bilirubin encephalopathy. Specifically, Hemolytic factors in infants with G6PD deficiency may lead to reduced hemoglobin and increased bilirubin levels in jaundiced infants.

Etiology analysis for term newborns with severe hyperbilirubinemia in eastern Guangdong of China

BACKGROUND

Neonatal hyperbilirubinemia is one of the common diseases of newborns that typically presents with yellow staining of skin, resulting in sequelaes such as hearing loss, motor and intellectual development disorders, and even death. The pathogenic factors of neonatal hyperbilirubinemia are complex. Different cases of hyperbilirubinemia may have a single or mixed etiology.

AIM

To explore the etiological characteristics of severe hyperbilirubinemia in term newborns of eastern Guangdong of China.

METHODS

Term newborns with severe hyperbilirubinemia in one hospital from January 2012 to December 2021 were retrospectively analyzed. The etiology was determined according to the laboratory results and clinical manifestations.

RESULTS

Among 1602 term newborns with hyperbilirubinemia in eastern Guangdong of China, 32.20% (580/1602) was severe hyperbilirubinemia. Among the causes of severe hyperbilirubinemia, neonatal hemolysis accounted for 15.17%, breast milk jaundice accounted for 12.09%, infection accounted for 10.17%, glucose-6-phosphate dehydrogenase (G6PD) deficiency accounted for 9.14%, and the coexistence of multiple etiologies accounted for 6.55%, unknown etiology accounted for 41.72%. ABO hemolysis and G6PD deficiency were the most common causes in the 20 cases with bilirubin encephalopathy. 94 severe hyperbilirubinemia newborns were tested for uridine diphosphate glucuronosyl transferase 1A1 (UGT1A1)*6 variant (rs4148323, c.211G>A, p.Arg71Gly), 9 cases were 211 G to A homozygous variant, 37 cases were 211 G to A heterozygous variant, and 48 cases were wild genotypes.

CONCLUSION

The main cause for severe hyperbilirubinemia and bilirubin encephalopathy in eastern Guangdong of China were the hemolytic disease of the newborns, G6PD deficiency and infection. UGT1A1 gene variant was also a high-risk factor for neonatal hyperbilirubinemia. Targeted prevention and treatment according to the etiology may reduce the occurrence of bilirubin encephalopathy and kernicterus.

UGT1A1*6 mutation associated with the occurrence and severity in infants with prolonged jaundice

BACKGROUND

This study aimed to investigate the influence of a variant of the UGT1A1 gene on the occurrence and severity of prolonged jaundice in Chinese infants at term.

METHODS

175 infants with prolonged jaundice and 149 controls were used in this retrospective case-control study. The infants with prolonged jaundice were subdivided into the mild-medium and severe jaundice groups (TSB ≥ 342 µmol/L). The frequency and genotype distribution of the UGT1A1 and G6PD genes, and clinical parameters including sex, birth weight, delivery mode, gestational age, and feeding mode, were analyzed, and the differences in the parameters between the two groups were compared.

RESULTS

The allele frequency of UGT1A1*6 in the prolonged jaundice group was higher than that in the control group. Similarly, it was also higher in the severe jaundice group than in the mild-medium jaundice group. Homozygous and heterozygous UGT1A1*6 were also found more frequently in the prolonged jaundice group than in the control group. Exclusive breastfeeding, homozygous and heterozygous forms of UGT1A1*6 were significant risk indicators for prolonged jaundice. Moreover, UGT1A1*6 was the best predictor of prolonged severe jaundice.

CONCLUSION

UGT1A1*6 appears to be a risk factor for prolonged jaundice with hyperbilirubinemia in term infants of Chinese ancestry who are exclusively breastfed.

Glucose-6-phosphate dehydrogenase deficiency screening and gene analysis in blood donors of Guangdong province

OBJECTIVES

The characteristic of glucose-6-phosphate dehydrogenase (G6PD) deficiency is red blood cell (RBC) destruction in response to oxidative stress. Patients requiring RBC transfusions may simultaneously receive oxidative medications or have concurrent infections, both of which can induce hemolysis in G6PD-deficient RBCs. We intend to investigate the incidence of G6PD deficiency in voluntary blood donors and to evaluate the transfusion risk associated with G6PD deficiency in Guangdong province.

METHODS

G6PD enzyme was analyzed in 3042 donors and gene mutations were genotyped in G6PD-deficient samples.

RESULTS

The G6PD-deficient prevalence of voluntary blood donors was 6.97% (212/3042), 55.19% blood donors with G6PD deficiency donated blood more than twice. Eighty-five cases of G6PD deficiency were genotyped, and the common types of G6PD mutations were c.1376 G > T, c.1388 G > A, c.95 A > G, c.1024 C > T, and c.871 G > A.

CONCLUSIONS

Due to the high prevalence of G6PD deficiency in Foshan area, we recommended that the screening of G6PD deficiency should be carried out for the regular blood donors to ensure the safety of blood users.

Effects of a Smartphone-Based Out-of-Hospital Screening App for Neonatal Hyperbilirubinemia on Neonatal Readmission Rates and Maternal Anxiety: Randomized Controlled Trial

Background

Neonatal hyperbilirubinemia is one of the leading causes of neonatal readmission—especially severe hyperbilirubinemia and its complications—and it influences disease burden as well as neonatal and maternal health. Smartphones have been shown to have satisfactory accuracy in screening neonatal bilirubin levels, but the impact of this technology on neonatal health care service and maternal health outcomes is still unknown.

Objective

The aim of this study was to evaluate the impact of a smartphone-based out-of-hospital neonatal jaundice screening program on neonatal readmission rates for jaundice and related maternal anxiety.

Methods

This was a 2-arm, unblinded, randomized controlled trial with 30 days of intervention and follow-up periods. From August 2019 to August 2020, healthy mother-infant dyads were recruited on-site from 3 public hospitals in Hainan, China. Intervention group mothers used the smartphone app to routinely monitor neonatal jaundice at home under the web-based guidance of pediatricians. Control group participants received routine care. The primary study outcome was the neonatal readmission rate due to jaundice within 30 days of the first hospital discharge. The secondary outcome was the maternal anxiety score associated with neonatal jaundice. The data were collected through a self-assessed questionnaire. All participants were included in the analysis (intention-to-treat).

Results

In this study, 1424 mother-infant dyads were recruited, comprising 1424 mothers and 1424 newborns. The median age of the mothers was 29 (IQR 26-32) years, and there were 714 (50.1%) male neonates. These mother-infant dyads were randomly assigned to the intervention group and the control group, with 712 dyads in each group; only 1187 of these dyads completed the follow-up. We found that the adjusted 30-day neonatal readmission rate due to jaundice reduced by 10.5% (71/605, 11.7% vs 141/582, 24.2%; 95% CI 5%-15.9%; odds ratio 0.4, 95% CI 0.3-0.5; P<.001) and the relevant maternal anxiety mean score decreased by 3.6 (95% CI –4.4 to –2.8; β=–3.6, 95% CI –4.5 to –2.8; P<.001) in the intervention group compared to those in the routine care group.

Conclusions

Our study shows that the smartphone-based out-of-hospital screening method for neonatal hyperbilirubinemia decreased the neonatal readmission rate within 30 days from the first discharge and improved maternal mental health to some degree, thus demonstrating the usefulness of this screening app for follow-up in pediatric care.

Trial Registration

China Clinical Trial Registration Center, ChiCTR2100049567; http://www.chictr.org.cn/showproj.aspx?proj=64245

Molecular heterogeneity of glucose-6-phosphate dehydrogenase deficiency in neonates in Wuhan: Description of four novel variants

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is one of the most common X-linked enzymopathies caused by G6PD gene variant. The aim of this study was to investigate the molecular epidemiological characteristic of the G6PD deficiency among newborn screening population in Wuhan region. A total of 430,806 healthy neonates in Wuhan area of China were screened for G6PD deficiency from November 2016 to December 2021. The positive samples were further detected with gene analysis. Among the 957 neonates with abnormal G6PD enzyme activity, the prevalence of G6PD deficiency in Wuhan was calculated as 0.22%. 38 genotypes were found and the top 5 frequencies of G6PD gene variants were c.1388G &gt; A, c.1376G &gt; T, c.95A &gt; G, c.1024C &gt; T and c.871G &gt; A. Seven rare single variants (c.25C &gt; T, c.152C &gt; T, c.406C &gt; T, c.497G &gt; A, c.679C &gt; T, c.854G &gt; A and c.1057C &gt; T) and two rare multiple variants (IVS-5 637/638T del/c.1311C &gt; T/1365-13T &gt; C and c.406C &gt; T/c.1311C &gt; T/1365-13T &gt; C) were discovered in this study. In addition, four novel variants (c.49C &gt; T, c.691G &gt; A, c.857A &gt; T and c.982G &gt; A) were detected out in our cohort, which have never been reported before. The result indicated that a rich diversity of G6PD genetic variants in Wuhan region, also had its own regional characteristic. Our data provided the basic knowledge for future prevention and research of G6PD deficiency and the findings will be useful for genetic counseling and prenatal diagnosis of G6PD deficiency in the Wuhan region.

Molecular Characterization and Genotype-Phenotype Correlation of G6PD Mutations in Five Ethnicities of Northern Vietnam

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme disorder and is caused by G6PD gene mutations. To date, more than 400 variants in the G6PD gene have been discovered, and about 160 identified variants are associated with a significant decrease in the G6PD enzyme activity. However, the molecular characterization and epidemiological study of G6PD deficiency are still limited in Vietnam. Therefore, we conducted this study to determine the G6PD variants among the Vietnamese populations and evaluate their correlation to G6PD enzyme activity. A total of 339 patients (302 males and 37 females) were enrolled in this study. The G6PD variants were identified by Sanger sequencing. Our results indicate that males are more severely deficient in G6PD than females. This enzyme activity in males (1.27 ± 1.06 IU/g·Hb) is significantly lower than in females (2.98 ± 1.57 IU/g·Hb) (p < 0.0001). The enzyme activity of the heterozygous-homozygous females and heterozygous females-hemizygous males was found to be significantly different (p < 0.05), which is interpreted due to random X-inactivation. For G6PD molecular characteristics, Viangchan (c.871G>A), Canton (c.1376G>T) and Kaiping (c.1388G>A) variants were the most dominant, accounting for 24.48%, 17.70%, and 22.42%, respectively, whereas the highest frequency of complex variants was observed in Viangchan/Silent with 20.35%. In terms of G6PD activity, the Union variant presented the lowest mean value (1.03 IU/g·Hb) compared to the other variants (p < 0.05). Computational analysis using Polyphen-2 tool investigated that all variants were relative to G6PD deficiency and separated the levels as benign and damaged. The result will establish effective methods to screen G6PD variants in Vietnam.

Simultaneous detection of G6PD mutations using SNPscan in a multiethnic minority area of Southwestern China

Objectives: Baise, a multiethnic inhabited area of southwestern China, is a historical malaria-endemic area with a high prevalence of G6PD deficiency. However, few studies of G6PD deficiency have been conducted in this region. Therefore, we performed a genetic analysis of G6PD deficiency in the Baise population from January 2020 to June 2021. Methods: A SNPscan assay was developed to simultaneously detect 33 common Chinese G6PD mutations. 30 G6PD-deficient samples were used for the method's validation. Then, a total of 709 suspected G6PD-deficient samples collated from the Baise population were evaluated for G6PD status, type of mutation and effect of mutations. Results: The SNPscan test had a sensitivity of 100% [95% confidence interval (CI): 94.87%-100%] and a specificity of 100% (95% CI: 87.66%-100%) for identifying G6PD mutations. A total of fifteen mutations were identified from 76.72% (544/709) of the samples. The most common mutation was discovered to be G6PD Kaiping (24.12%), followed by G6PD Canton (17.91%), and G6PD Gaohe (11.28%). We compared the G6PD mutation spectrum among Zhuang, Han and other Southeast Asian populations, and the Zhuang population's mutation distribution was quite similar to that in the Han population. Conclusion: This study provided a detailed G6PD mutation spectrum in Baise of southwestern China and will be valuable for the diagnosis and research of G6PD deficiency in this area. Furthermore, the SNPscan assay could be used to quickly diagnose these G6PD mutations accurately.

Newborn Screening for G6PD Deficiency in Xiamen, China: Prevalence, Variant Spectrum, and Genotype-Phenotype Correlations

Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common inherited enzymatic defect. The purpose of this study was to evaluate the profile of G6PD deficiency and investigate the factors associated with the accuracy of newborn screening (NBS) in Xiamen, China.

Methods: A total of 99,546 newborns were screened by modified fluorescent spot test at the Women and Children’s Hospital, Xiamen University. High-risk neonates were recalled for diagnosis by either a measurement of G6PD activity or genetic testing for the presence of pathogenic G6PD variants using a quantitative G6PD enzymatic assay or the MeltPro® G6PD assay, respectively.

Results: In the first-tier screening, 1,256 newborns were categorized as high risk. Of these, 1,051 were diagnosed with G6PD deficiency, indicating a prevalence of 1.39% in Xiamen, China. Among the 1,013 neonates who underwent genotyping, 851 carried hemizygous, heterozygous, homozygous, or compound heterozygous variants, for a positive predictive value (PPV) of 84.01%. In total, 12 variants and 32 genotypes were identified, and the six most common variants were c.1376G>T, c.1388G>A, c.95A>G, c.1024C>T, c.871G>A, and c.392G>T, which accounted for approximately 94% of the identified alleles. Different variants showed characteristic enzymatic activities, although high phenotypic heterogeneity was observed for each variant. The use of cold-chain transportation significantly improved the PPV of NBS.

Conclusions: We determined the profile of G6PD deficiency in Xiamen, including the prevalence, variant spectrum, and genotype-phenotype correlations and confirmed that maintaining a low temperature during sample transport is essential to ensure the high screening accuracy of NBS. Our data provides epidemiological, genotypic, phenotypic, and clinical practice references to standardize future interventions for G6PD deficiency.

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

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.

Current investigations on clinical pharmacology and therapeutics of Glucose-6-phosphate dehydrogenase deficiency

Glucose-6-phospate dehydrogenase (G6PD) deficiency is estimated to affect more than 400 million people world-wide. This X-linked genetic deficiency puts stress on red blood cells (RBC), which may be further augmented under certain pathophysiological conditions and drug treatments. These conditions can cause hemolytic anemia and eventually lead to multi-organ failure and mortality. G6PD is involved in the rate-limiting step of the pentose phosphate pathway, which generates reduced nicotinamide adenine dinucleotide phosphate (NADPH). In RBCs, the NADPH/G6PD pathway is the only source for recycling reduced glutathione and provides protection from oxidative stress. Susceptibility of G6PD deficient populations to certain drug treatments and potential risks of hemolysis are important public health issues. A number of clinical trials are currently in progress investigating clinical factors associated with G6PD deficiency, validation of new diagnostic kits for G6PD deficiency, and evaluating drug safety, efficacy, and pathophysiology. More than 25 clinical studies in G6PD populations are currently in progress or have just been completed that have been examined for clinical pharmacology and potential therapeutic implications of G6PD deficiency. The information on clinical conditions, interventions, purpose, outcome, and status of these clinical trials has been studied. A critical review of ongoing clinical investigations on pharmacology and therapeutics of G6PD deficiency should be highly important for researchers, clinical pharmacologists, pharmaceutical companies, and global public health agencies. The information may be useful for developing strategies for treatment and control of hemolytic crisis and potential drug toxicities in G6PD deficient patients.

Glucose-6-phosphate dehydrogenase deficiency in the Han Chinese population: molecular characterization and genotype-phenotype association throughout an activity distribution

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common hereditary disorder in China. The existing prevalence and molecular epidemiology of G6PD deficiency in China were geographically limited. In this study, the spectrum of G6PD gene mutations was well characterized in a large and diverse population all over the country; and the correlation of genotype and enzyme activity phenotype was explored for the first time. The results showed that the overall prevalence of G6PD deficiency in China was 2.10% at the national level. The top six common mutations were c.1388 G>A, c.1376 G>T, c.95 A>G, c.392 G>T, c.871 G>A and c.1024 C>T, accounting for more than 90% of G6PD deficient alleles. Compound mutation patterns were frequently observed in females with severe deficiency. The distribution of G6PD activities depended on the type of mutation patterns and genders. Hemizygote, homozygote, and compound heterozygote were predominantly associated with severe G6PD deficiency, whereas heterozygotes with single mutation mainly presented moderate enzyme deficiency. A significant gap between G6PD activities in hemizygous and normal males was observed, and yet, the overall distribution of that in females carrying missense mutations was a continuum from G6PD severely deficient to normal. This is the first report of discussing the association between G6PD genetic variants in the Chinese and enzyme activity phenotypes.

Lacrimal sac bacteriology and susceptibility pattern in infants with congenital nasolacrimal duct obstruction in the 1st year of life: a cross-sectional study

Background

Congenital nasolacrimal duct obstruction (CNLDO) is one of the main causes of epiphora in infants, and antibiotics are usually used as a conservative therapy in the first year. Yet, little is known about the bacteriology of the occluded lacrimal drainage system in this group of patients. The aim of this study was to evaluate the microbiology of lacrimal sac (LS) in Chinese children with CNLDO in their first year of life.

Methods

Patients with CNLDO between May 1, 2017 and August 31, 2018 at a tertiary care children’s hospital were enrolled. The study recruited infants who received lacrimal probing under 1 year old, and refluxed discharge from LS was collected. Samples were cultured and susceptibility test was performed for positive culture.

Results

Thirty-two patients with CNLDO were included. The ratio of male to female was 23:9. The mean age was 6.7 ± 2.4 (1.7–12) months. Positive cultures was identified in 87.5% of the sample, and presented 38 strains of bacteria. Mixed infection was identified in 10 (31.3%) children. Gram-positive bacteria accounted for 60.5% of all the strains, with Streptococcus (50%) being the most frequent species, whereas Haemophilus (21.1%) and Neisseriae (13.2%) were most common isolates for Gram-negative organisms. Methicillin-resistant Staphylococcus aureus (MRSA) was detected in 2 infants whose symptoms resolved by a routine probing. No difference of bacteriology pattern was detected between patients under 6 months old and those beyond. The pathogens were highly sensitive to chloramphenicol (88%) and levofloxacin (84%), but resistant to erythromycin (40%) and sulfamethoxazole (32%).

Conclusions

Infants with CNLDO under 1 year of age presented predominance of Streptococcus as Gram-positive organism, and Haemophilus as Gram-negative organism. Levofloxacin was an active topical antibiotic agent with few chance of resistance especially for Chinese children. These findings could help clinicians choose optimal medicine for CNLDO as the conservative treatments.