Prevalence and Molecular Characterization of Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency in Females from Previously Malaria Endemic Regions in Northeastern Thailand and Identification of a Novel G6PD Variant

Prevalence of Glucose-6-Phosphate Dehydrogenase Deficiency in Male Newborn Infants and Its Relationship with Neonatal Jaundice in Thailand

OBJECTIVE

 The study aimed to explore the prevalence of glucose-6-phosphate dehydrogenase (G-6-PD) deficiency among male newborn infants in northeastern Thailand and its relationship with neonatal jaundice (NJ).

STUDY DESIGN

 This prospective cohort study included male newborn infants with gestational age (GA) ≥35 weeks born between July 1, 2019, and March 1, 2021. Cord blood was sent for G-6-PD fluorescent spot test (FST) and results were reported as normal, partial, or complete deficiency. Infants with NJ would have blood tested for total serum bilirubin (TSB) level and other possible causes of NJ. Duration of phototherapy, length of hospital stays, and complications were documented.

RESULTS

 There were 922 male infants included in this study with 854 (93.1%) term and 63 (6.9%) preterm infants. FST showed 132 infants (14.4%) had G-6-PD deficiency. Incidence of NJ was significantly higher among infants with G-6-PD deficiency compared with infants with normal G-6-PD level (47.7 vs. 25.8%; relative risk [RR]: 2.62, 95% confidence interval [CI]: 1.79-3.82; p < 0.001). Regardless of G-6-PD level, preterm infants had significantly higher incidence of NJ than term infants (52.4 vs. 27.3%; RR: 2.93, 95% CI: 1.75-4.92; p < 0.001). Duration of phototherapy was significantly longer in infants with G-6-PD deficiency with NJ but hospital stays were similar. Infants with combined G-6-PD deficiency and other causes of hemolysis did not have higher TSB level than infants with isolated G-6-PD deficiency. Risk factors associated with NJ were G-6-PD deficiency and preterm infants, whereas more advance GA was associated with reduced risk for NJ.

CONCLUSION

 G-6-PD deficiency and preterm infants were important risk factors for NJ. Routine G-6-PD screening, close monitoring for signs of NJ in infant with risks, and appropriate parental counseling should be implemented.

KEY POINTS

· G-6-PD deficiency increases risk of neonatal jaundice.. · Preterm infants have higher risk for neonatal jaundice.. · G-6-PD deficiency does not link with severe jaundice..

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

Background

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked recessive Mendelian genetic disorder characterized by neonatal jaundice and hemolytic anemia, affecting more than 400 million people worldwide. The purpose of this research was to investigate prevalence rates of G6PD deficiency and to evaluate and establish specific cut-off values in early prediction of G6PD deficiency by regions (HeFei, FuYang, AnQing) on different seasons, as well as to investigate the frequencies of G6PD gene mutations among three regions mentioned above.

Methods

A total of 31,482 neonates (21,402, 7680, and 2340 for HeFei, FuYang, and AnQing cities, respectively) were recruited. Positive subjects were recalled to attend genetic tests for diagnosis. G6PD activity on the Genetic screening processor (GSP analyzer, 2021-0010) was measured following the manufactureržs protocol. The cut-off value was first set to 35 U/dL. The receiver operating characteristics (ROC) curve was employed to assess and compare the efficiency in predicting G6PD deficiency among HeFei, FuYang, and AnQing cities in different seasons.

Population pharmacogenomics: an update on ethnogeographic differences and opportunities for precision public health

Both safety and efficacy of medical treatment can vary depending on the ethnogeographic background of the patient. One of the reasons underlying this variability is differences in pharmacogenetic polymorphisms in genes involved in drug disposition, as well as in drug targets. Knowledge and appreciation of these differences is thus essential to optimize population-stratified care. Here, we provide an extensive updated analysis of population pharmacogenomics in ten pharmacokinetic genes (CYP2D6, CYP2C19, DPYD, TPMT, NUDT15 and SLC22A1), drug targets (CFTR) and genes involved in drug hypersensitivity (HLA-A, HLA-B) or drug-induced acute hemolytic anemia (G6PD). Combined, polymorphisms in the analyzed genes affect the pharmacology, efficacy or safety of 141 different drugs and therapeutic regimens. The data reveal pronounced differences in the genetic landscape, complexity and variant frequencies between ethnogeographic groups. Reduced function alleles of CYP2D6, SLC22A1 and CFTR were most prevalent in individuals of European descent, whereas DPYD and TPMT deficiencies were most common in Sub-Saharan Africa. Oceanian populations showed the highest frequencies of CYP2C19 loss-of-function alleles while their inferred CYP2D6 activity was among the highest worldwide. Frequencies of HLA-B*15:02 and HLA-B*58:01 were highest across Asia, which has important implications for the risk of severe cutaneous adverse reactions upon treatment with carbamazepine and allopurinol. G6PD deficiencies were most frequent in Africa, the Middle East and Southeast Asia with pronounced differences in variant composition. These variability data provide an important resource to inform cost-effectiveness modeling and guide population-specific genotyping strategies with the goal of optimizing the implementation of precision public health.

Acalypha indica induced transient glucose-6-phosphate dehydrogenase deficiency with acute haemolysis

Acalypha indica is a tropical herb found in Asia. The entire plant, especially the leaves, is used in herbal medicine for several therapeutic purposes. Acute intravascular haemolysis and methaemoglobinaemia have been reported in patients who consume this herb. We present a case of a previously healthy middle-aged man who ingested boiled leaves of A. indica The patient developed clinical symptoms and signs of intravascular haemolysis 7 days after ingestion. Peripheral blood smear showed typical findings of glucose-6-phosphate dehydrogenase (G6PD) deficiency with acute haemolysis. The G6PD activity was low during active haemolysis. The G6PD level, however, returned to normal after 4 months of follow-up. The patient was further tested for common G6PD gene mutations in Southeast Asia and was negative. Ingestion of A. indica may induce transient G6PD deficiency, which in this patient led to acute haemolysis and methaemoglobinaemia.

The ethnogeographic variability of genetic factors underlying G6PD deficiency

Glucose-6-phosphate dehydrogenase (G6PD) deficiency caused by genetic variants in the G6PD gene, constitutes the most common enzymopathy worldwide, affecting approximately 5% of the global population. While carriers are mostly asymptomatic, they are at substantial risk of acute hemolytic anemia upon certain infections or exposure to various medications. As such, information about G6PD activity status in a given patient can constitute an important parameter to guide clinical decision-making. Here, we leveraged whole genome sequencing data from 142,069 unrelated individuals across seven human populations to provide a global comprehensive map of G6PD variability. By integrating established functional classifications with stringent computational predictions using 13 partly orthogonal algorithms for uncharacterized and novel variants, we reveal the large extent of ethnogeographic variability in G6PD deficiency and highlight its population-specific genetic composition. Overall, estimated disease prevalence in males ranged between 12.2% in Africans, 2.7-3.5% across Asia and 2.1% in Middle Easterners to < 0.3% in Europeans, Finnish and Amish. In Africans, the major deficient alleles were A-^202A/376 G (minor allele frequency 11.6%) and A-^{968 C/376 G} (0.5%). In contrast, G6PD deficiency in Middle Easterners was primarily due to the Mediterranean allele (1.3%) and the population-specific Cairo variant (0.4%). In South Asia, the most prevalent deficient alleles were Mediterranean (1.7%), Kerala (1.1%), Gond (0.9%) and Orissa (0.2%), whereas in East Asian populations the Canton (1.1%), Kaiping (0.7%) and Viangchan (0.3%) variants were predominant. Combined, our analyses provide a large dataset of G6PD variability across major ethnogeographic groups and can instruct population-specific genotyping strategies to optimize genetically guided therapeutic interventions.