Should we screen newborns for glucose-6-phosphate dehydrogenase deficiency in the United States?

Implementation of Universal Screening for G6PD Deficiency in Newborns

We describe the implementation of universal glucose-6-phosphate dehydrogenase (G6PD) screening during the first year of New York State mandated testing, as well as operational challenges and clinical knowledge gained. All infants born at or transferred to our center between June 21, 2022 and June 30, 2023, underwent testing for G6PD enzyme deficiency and were included in the study cohort. Infant blood samples were collected and sent to a reference laboratory for quantitative assay. After initiation of universal screening, a quality improvement initiative was launched to:monitor and improve the suitability of blood sample collection to ensure timely return of results;improve the reliability and validity of the reference laboratory enzyme assay; andestablish accurate reference ranges for G6PD deficiency in newborns.A total of 5601 newborns were included. Within the first year of implementation, the percentage of samples yielding any test result increased from 76% to 85%, and most patients had a G6PD result available within 1 day of discharge. We established a more accurate threshold for G6PD deficiency in newborns of <4.9 U/g Hb and G6PD intermediate of <10.0 U/g Hb. Using the updated reference ranges, 224 patients in our cohort were identified as G6PD deficient or intermediate (4.0%). Through a quality-sensitive process, we identified the importance of a standardized approach, improved sample collection processes, decreased sample turnaround time, and established more accurate reference ranges. We hope our experiences will help others seeking to improve processes and implement similar programs at other institutions.

Georacial Epidemiological Estimates of Glucose-6-Phosphate Dehydrogenase Deficiency among Newborns in the United States

OBJECTIVE

 Glucose-6-phosphate dehydrogenase deficiency (G6PDd) is the most common inherited enzyme deficiency disorder worldwide and a major risk factor for the development of severe hyperbilirubinemia. Racial diversity of phenotypes and genotypes in affected individuals is likely to exist in the United States because of changing population demographics. The aim of the present study was to predict an empirical estimate of annual prevalence of G6PDd in newborns adjusted for geography (state of birth), maternal racial identity, and sex of the infant.

STUDY DESIGN

 Birth statistics (2019) from National Center for Vital Statistics and CDC-WONDER data and race-specific prevalence of G6PDd in the United States were evaluated from published sources. We developed Simpson's diversity index (DI) for each State and correlated these to rates of G6PDd in neonates. Descriptive statistics including modeled prevalence and its association with DI were assessed using the Spearman's rho correlation test. We modeled state-specific prevalence for six states (California, Washington DC, Illinois, Massachusetts, New York, and Pennsylvania) using population-level allele frequencies and race, based on Hardy-Weinberg equilibrium.

RESULTS

 We estimated 78,010 (95% confidence interval: 76,768-79,252) newborns had G6PDd at birth in 2019 with cumulative median prevalence of 17.3 (interquartile range: 12.4-23.2) per 1,000 live births for United States. A strong association was noted for DI and prevalence of G6PDd (p < 0.0005). Five states (Washington DC, Mississippi, Louisiana, Georgia, and Maryland) have the highest projected G6PDd prevalence, with a range of 35 to 48 per 1,000 live births. The probability of G6PDd for female heterozygotes, based on male prevalence, ranged from 1.1 to 7.5% for each cohort in the select six states.

CONCLUSION

 States with diverse populations are likely to have higher rates of G6PDd. These prevalence estimates exceeded by several-fold when compared with disorders screened by existing state mandated newborn screening panels. These discrepancies are further confounded by known risk of severe neonatal hyperbilirubinemia that results with G6PDd and the life-long risk of hemolysis. Combined universal newborn predischarge screening for G6PDd and bilirubin could alert and guide a clinician's practices for parental education and closer medical surveillance during the vulnerable neonatal time period.

KEY POINTS

· G6PDd is a common X-linked disorder that can present with varied phenotypes among newborns.. · Prevalence of G6PDd and genotype distribution varies with sex, race, and ethnicity.. · We present regional race- and sex-based estimates of G6PDd in the United States..

Evidence Suggests a Decrease in the Incidence of Kernicterus in California

We identified children diagnosed with kernicterus in the California Department of Developmental Services and estimated an incidence of 0.42 per 100 000 births from 1988 to 2014, significantly decreasing to 0.04 per 100 000 births after 2009. We also examined national infant kernicterus mortality from 1979 to 2016 using CDC data. It did not decrease significantly.

Technical evaluation and usability of a quantitative G6PD POC test in cord blood: a mixed-methods study in a low-resource setting

OBJECTIVES

New point-of-care (POC) quantitative G6PD testing devices developed to provide safe radical cure for Plasmodium vivax malaria may be used to diagnose G6PD deficiency in newborns at risk of severe neonatal hyperbilirubinaemia, improving clinical care, and preventing related morbidity and mortality.

METHODS

We conducted a mixed-methods study analysing technical performance and usability of the 'STANDARD G6PD' Biosensor when used by trained midwives on cord blood samples at two rural clinics on the Thailand-Myanmar border.

RESULTS

In 307 cord blood samples, the Biosensor had a sensitivity of 1.000 (95% CI: 0.859 to 1.000) and a specificity of 0.993 (95% CI: 0.971 to 0.999) as compared with gold-standard spectrophotometry to diagnose G6PD-deficient newborns using a receiver operating characteristic (ROC) analysis-derived threshold of ≤4.8 IU/gHb. The Biosensor had a sensitivity of 0.727 (95% CI: 0.498 to 0.893) and specificity of 0.933 (95% CI: 0.876 to 0.969) for 30%-70% activity range in girls using ROC analysis-derived range of 4.9-9.9 IU/gHb. These thresholds allowed identification of all G6PD-deficient neonates and 80% of female neonates with intermediate phenotypes.Need of phototherapy treatment for neonatal hyperbilirubinaemia was higher in neonates with deficient and intermediate phenotypes as diagnosed by either reference spectrophotometry or Biosensor.Focus group discussions found high levels of learnability, willingness, satisfaction and suitability for the Biosensor in this setting. The staff valued the capacity of the Biosensor to identify newborns with G6PD deficiency early ('We can know that early, we can counsel the parents about the chances of their children getting jaundice') and at the POC, including in more rural settings ('Because we can know the right result of the G6PD deficiency in a short time, especially for the clinic which does not have a lab').

CONCLUSIONS

The Biosensor is a suitable tool in this resource-constrained setting to identify newborns with abnormal G6PD phenotypes at increased risk of neonatal hyperbilirubinaemia.

Functional characterization of the p.(Gln195His) or Tainan and novel p.(Ser184Cys) or Toluca glucose-6-phosphate dehydrogenase (G6PD) gene natural variants identified through Mexican newborn screening for glucose-6-phosphate dehydrogenase deficiency

BACKGROUND

Newborn screening for glucose-6-phosphate dehydrogenase deficiency (G6PDd) was implemented in Mexico beginning in 2017. In a Mexican population, genotyping analysis of G6PD as a second-tier method identified a previously unreported missense variant, p.(Ser184Cys), which we propose to call "Toluca", and the extremely rare p.(Gln195His) or "Tainan" variant, which was previously described in the Taiwanese population as a Class II allele through in silico evaluations. Here, we sought to perform in vitro biochemical characterizations of the Toluca and Tainan G6PD natural variants and describe their associated phenotypes.

METHODS

The "Toluca" and "Tainan" variants were identified in three unrelated G6PDd newborn males, two of whom lacked evidence of acute hemolytic anemia (AHA) or neonatal hyperbilirubinemia (NHB). We constructed wild-type (WT), Tainan, and Toluca G6PD recombinant enzymes and performed in vitro assessments.

RESULTS

Both variants had diminished G6PD expression, decreased affinities for glucose-6-phosphate and NADP⁺ substrates, significant decreases in catalytic efficiency (∼97 % with respect to WT-G6PD), and diminished thermostabilities that were partially rescued by NADP⁺. In silico protein modeling predicted that the variants would have destabilizing effects on the protein tertiary structure, potentially reducing the enzyme half-lives and/or catalytic efficiencies.

CONCLUSION

Our data suggest that G6PD "Tainan" and "Toluca" are potential Class II natural variants, which agrees with the absence of chronic nonspherocytic hemolytic anemia (CNSHA) in our patients. It remains to be determined whether these variants represent high-risk genetic factors for developing CNSHA, AHA, and/or NHB.

Thirty-five males with severe (Class 1) G6PD deficiency (c.637G>T) in a North American family of European ancestry

In North America, jaundiced neonates are not usually tested for G6PD deficiency if the family is of European ancestry. However, we describe such a family where ≥35 males have had severe (Class I) G6PD deficiency. Many of the jaundiced neonates did not have this diagnosis considered, at least three of whom developed bilirubin neurotoxicity. Over seven generations 35 affected males were identified. Three developed signs of kernicterus spectrum disorder; three had exchange transfusions for hyperbilirubinemia; and nine received one or more blood transfusions during childhood.

Severe Presentation of Congenital Hemolytic Anemias in the Neonatal Age: Diagnostic and Therapeutic Issues

Congenital hemolytic anemias (CHAs) are a group of diseases characterized by premature destruction of erythrocytes as a consequence of intrinsic red blood cells abnormalities. Suggestive features of CHAs are anemia and hemolysis, with high reticulocyte count, unconjugated hyperbilirubinemia, increased lactate dehydrogenase (LDH), and reduced haptoglobin. The peripheral blood smear can help the differential diagnosis. In this review, we discuss the clinical management of severe CHAs presenting early on in the neonatal period. Appropriate knowledge and a high index of suspicion are crucial for a timely differential diagnosis and management. Here, we provide an overview of the most common conditions, such as glucose-6-phosphate dehydrogenase deficiency, pyruvate kinase deficiency, and hereditary spherocytosis. Although rare, congenital dyserythropoietic anemias are included as they may be suspected in early life, while hemoglobinopathies will not be discussed, as they usually manifest at a later age, when fetal hemoglobin (HbF) is replaced by the adult form (HbA).

Glucose-6-Phosphate Dehydrogenase Deficiency and the Benefits of Early Screening

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common enzymopathy worldwide, is an insufficient amount of the G6PD enzyme, which is vital to the protection of the erythrocyte. Deficient enzyme levels lead to oxidative damage, hemolysis, and resultant severe hyperbilirubinemia. If not promptly recognized and treated, G6PD deficiency can potentially lead to bilirubin-induced neurologic dysfunction, acute bilirubin encephalopathy, and kernicterus. Glucose-6-phosphate dehydrogenase deficiency is one of the three most common causes for pathologic hyperbilirubinemia. A change in migration patterns and intercultural marriages have created an increased incidence of G6PD deficiency in the United States. Currently, there is no universally mandated metabolic screening or clinical risk assessment tool for G6PD deficiency in the United States. Mandatory universal screening for G6PD deficiency, which includes surveillance and hospital-based risk assessment tools, can identify the at-risk infant and foster early identification, diagnosis, and treatment to eliminate neurotoxicity.

Causes of severe neonatal hyperbilirubinemia: a multicenter study of three regions in China

BACKGROUND

Available evidence suggests that our country bear great burden of severe hyperbilirubinemia. However, the causes have not been explored recently in different regions of China to guide necessary clinical and public health interventions.

METHODS

This was a prospective, observational study conducted from March 1, 2018, to February 28, 2019. Four hospitals in three regions of China participated in the survey. Data from infants with a gestational age ≥ 35 weeks, birth weight ≥ 2000 g, and total serum bilirubin (TSB) level ≥ 17 mg/dL (342 µmol/L) were prospectively collected.

RESULTS

A total of 783 cases were reported. Causes were identified in 259 cases. The major causes were ABO incompatibility (n = 101), glucose-6-phosphate dehydrogenase deficiency (n = 76), and intracranial hemorrhage (n = 70). All infants with glucose-6-phosphate dehydrogenase deficiency were from the central south region. Those from the central south region had much higher peak total bilirubin levels [mean, 404 μmol/L; standard deviation (SD), 75 μmol/L] than those from the other regions (mean, 373 μmol/L; SD, 35 μmol/L) (P < 0.001).

CONCLUSIONS

ABO incompatibility was the leading cause in the east and northwest regions, but cases in the central south region were mainly caused by both ABO incompatibility and glucose-6-phosphate dehydrogenase deficiency, and infants in this region had a much higher peak total bilirubin level. Intracranial hemorrhage may be another common cause. More thorough assessments and rigorous bilirubin follow-up strategies are needed in the central south region.

Educational Case: Anemia in a Neonate

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Prevalence of G6PD deficiency in Iranian neonates with jaundice: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis study aimed to estimate the overall prevalence of Glucose-6-phosphate dehydrogenase (G6PD) deficiency in neonates with jaundice who were admitted to hospitals in Iran.

MATERIALS AND METHODS

In this systematic review and meta-analysis, we searched PubMed/Medline, Scopus, ISI Web of Sciences, and Iranian Local databases up to December 2019.We calculated Prevalence and 95% Confidence Interval (95% CI) of G6PD deficiency as summary measures. We conducted subgroup analysis based on the sex and quality of studies, while meta-regression were applied for investigating the effect of years of studies and years of publication on the pooled prevalence. We applied sensitivity analysis to investigate the effect of excluding each study on the pooled prevalence estimation.

RESULTS

The total sample size was 9799 people. The pooled prevalence of G6PD deficiency among neonates with jaundice in Iran was 7.0% (95% CI: 5.5-8.5%). The results of subgroup analysis showed that, pooled prevalence of G6PD deficiency among male neonate (12.1%, 95%CI: 7.6-16.7%) was more prevalent that female (3.00%, 95%CI: 1.1-4.9%). Based on the sensitivity analysis, lower and higher pooled prevalence of G6PD deficiency was observed 5.8% (95%CI: 4.7-6.9%) and 7.3% (95%CI: 5.7-8.8%) respectively by excluding each study.

CONCLUSION

The overall prevalence of G6PD deficiency was 7% in Iranian neonates with Jaundice. Prevalence was high in male and early hours of life. We recommend screening test for G6PD deficiency in neonates to prevent its complications.

A novel point-of-care device for measuring glucose-6-phosphate dehydrogenase enzyme deficiency

Extreme hyperbilirubinemia can cause bilirubin neurotoxicity. Infants with glucose-6-phosphate dehydrogenase (G6PD) deficiency can develop hemolysis and thus are at high risk. We evaluated a device that quantitatively measures G6PD activity kinetically using digital microfluidics (DMF). Intra- and inter-instrument and -day imprecision (CVs) were first assessed. G6PD activity in 86 samples was then measured and compared between DMF and 2 reference methods. Overall DMF reproducibility was 3.8% over 5 days by 2 operators on 2 instruments. Mean intra- and inter-instrument variabilities were 3.6% and 3.9%, respectively (n = 28), with a user variability of 4.3%. Mean G6PD activity was 6.40±4.62 and 6.37±4.62 U/g hemoglobin for DMF and Reference Methods 1 (n = 46) and 12.15±3.86 and 11.48±1.55 for DMF and 2 (n = 40), respectively, and strongly correlated (r = 0.95 and 0.95) with mean biases of +0.04±2.90 and +0.67±1.55 for methods 1 and 2, respectively. The novel device could be used for early newborn G6PD screening.

Combating the Hidden Health Disparity of Kernicterus in Black Infants: A Review

IMPORTANCE

Kernicterus is a devastating, permanently disabling neurologic condition resulting from bilirubin neurotoxicity. Black neonates account for more than 25% of kernicterus cases in the US, despite making up only approximately 14% of all births. This is a largely overlooked health disparity.

OBSERVATIONS

The black kernicterus health disparity exists despite a lower overall incidence of clinically significant hyperbilirubinemia among black neonates, a paradox recently explained by a previously unrecognized risk for hazardous hyperbilirubinemia. Aligned with national and global health initiatives to reduce or eliminate health disparities, this review highlights the multiple biologic and nonbiologic factors contributing to kernicterus risk in black infants and approaches to reduce this health disparity. This includes both parent-level and clinician-level kernicterus prevention strategies, with an emphasis on improving parental health literacy on neonatal jaundice and acute bilirubin encephalopathy and clinician awareness of the key factors that contribute to hazardous hyperbilirubinemia risk in this vulnerable group. Parent-level prevention strategies include efforts to improve their health literacy on neonatal jaundice and acute bilirubin encephalopathy and empower care seeking for jaundice. Clinician-level prevention strategies include efforts to eliminate community and institutional barriers that impede access to care, heighten clinician awareness of the factors that contribute to kernicterus risk in this vulnerable patient group, and strengthen newborn hyperbilirubinemia management and bilirubin surveillance.

CONCLUSIONS AND RELEVANCE

There are multiple opportunities for intervention to reduce black kernicterus risk. Although kernicterus is a rare disorder, the incidence among black infants is not a trivial matter nor are efforts to prevent kernicterus. While the multiple interacting biologic and nonbiologic contributors to increased kernicterus risk among black infants pose a considerable challenge to clinicians, there are opportunities for intervention to reduce this risk and health disparity. Continued study is imperative to understand the current scope of kernicterus and its occurrence in black neonates.

Fasting glucose-to-HbA1c ratio is a good indicator of G6PD deficiency, but not thalassemia, in patients with type 2 diabetes mellitus

AIMS

Patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency or thalassemia have a shorter red blood cell lifespan; therefore, HbA1c is underestimated in these patients. To address these issues, we sought an early indicator for G6PD deficiency or thalassemia in DM patients.

METHODS

A total of 4908 patients with DM and 1848 subjects without DM were included in this study. Fasting glucose (FG) levels, HbA1c levels, hemogram profiles and G6PD activities were measured. Genotypic analyses of G6PD deficiency and thalassemia were performed.

RESULTS

DM patients with G6PD deficiency had significantly higher FG/HbA1c ratios than did those without G6PD deficiency (26.54 vs. 18.36; p < 0.0001). We divided the FG level into four categories: ≤150, 151-250, 251-350, and ≥351 mg/dL. Among all groups, only patients with DM and G6PD deficiency had higher FG/HbA1c ratios than those of patients with DM alone or DM with thalassemia. To evaluate the reliability of the FG/HbA1c ratio, receiver operating characteristic analyses were performed. The areas under the curve for detecting FG ≤ 150, 151-250, 251-350, and ≥351 mg/dL with G6PD deficiency based on the FG/HbA1c ratio were 0.839 (p < 0.001), 0.888 (p < 0.001), 0.891 (p < 0.001), and 0.640 (p = 0.3954), respectively. G6PD deficiency was confirmed by genetic analysis. We found common mutations that influenced G6PD activity and HbA1c levels.

CONCLUSIONS

The FG/HbA1c ratio is a good indicator of DM with G6PD deficiency. If this ratio is determined to be high in a clinical setting, then the clinician must consider whether the patient has a G6PD deficiency, and HbA1c reference values must be adjusted to avoid misdiagnosis and incorrect treatment decisions.

Prevalence of neonatal hyperbilirubinaemia and its association with glucose-6-phosphate dehydrogenase deficiency and blood-type incompatibility in sub-Saharan Africa: a systematic review and meta-analysis

BACKGROUND

Hyperbilirubinaemia is a silent cause of newborn disease and death worldwide. However, studies of the disease in sub-Saharan Africa are highly variable with respect to its prevalence. Hence, this study aimed to estimate the overall magnitude of neonatal hyperbilirubinaemia and its association with glucose-6-phosphate dehydrogenase (G6PD) deficiency and blood-type incompatibility in sub-Saharan Africa.

METHODS

PubMed, Scopus, Google Scholar and the Cochrane Review were systematically searched online to retrieve hyperbilirubinaemia-related articles. All observational studies reported the prevalence of hyperbilirubinaemia in sub-Saharan Africa were included for analysis and excluded if the study failed to determine the desired outcome. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Heterogeneity across the included studies was evaluated using the inconsistency index (I²). Subgroup and meta- regression analysis were also done. Publication bias was examined by funnel plot and the Egger's regression test. The random-effect model was fitted to estimate the pooled prevalence of neonatal hyperbilirubinaemia. The meta-analysis was performed using the STATA V.14 software.

RESULTS

A total of 30 486 studies were collected from the different databases and 10 articles were included for the final analysis. The overall magnitude of neonatal hyperbilirubinaemia was 28.08% (95% CI20.23 to 35.94, I²=83.2) in sub-Saharan Africa. Neonates with G6PD deficiency (OR 2.42, 95% CI 1.64 to 3.56, I²=37%) and neonates that had a blood type that was incompatible with their mother's (OR 3.3, (95% CI 1.96 to 5.72, I²=84%) were more likely to develop hyperbilirubinaemia.

CONCLUSION

The failure to prevent and screen G6PD deficiency and blood-type incompatibility with their mother's results in high burden of neonatal hyperbilirubinaemia in sub-Saharan Africa. Therefore, early identification and care strategies should be developed to the affected neonates with G6PD deficiency and blood-type incompatibility with their mother's to address long-term medical and scholastic damages among those exposed to hyperbilirubinaemia.

Digital Microfluidic Platform to Maximize Diagnostic Tests with Low Sample Volumes from Newborns and Pediatric Patients

"Children are not tiny adults" is an adage commonly used in pediatrics to emphasize the fact that children often have different physiological responses to sickness and trauma compared to adults. However, despite widespread acceptance of this concept, diagnostic blood testing is an excellent example of clinical care that is not yet customized to the needs of children, especially newborns. Cumulative blood loss resulting from clinical testing does not typically impact critically ill adult patients, but can quickly escalate in children, leading to iatrogenic anemia and related comorbidities. Moreover, the tests prioritized for rapid, near-patient testing in adults are not always the most clinically relevant tests for children or newborns. This report describes the development of a digital microfluidic testing platform and associated clinical assays purposely curated to address current shortcomings in pediatric laboratory testing by using microliter volumes (<50 µL) of samples. The automated platform consists of a small instrument and single-use cartridges, which contain all reagents necessary to prepare the sample and perform the assay. Electrowetting technology is used to precisely manipulate nanoliter-sized droplets of samples and reagents inside the cartridge. To date, we have automated three disparate types of assays (biochemical assays, immunoassays, and molecular assays) on the platform and have developed over two dozen unique tests, each with important clinical application to newborns and pediatric patients. Cell lysis, plasma preparation, magnetic bead washing, thermocycling, incubation, and many other essential functions were all performed on the cartridge without any user intervention. The resulting assays demonstrate performance comparable to standard clinical laboratory assays and are economical due to the reduced hands-on effort required for each assay and lower overall reagent consumption. These capabilities allow a wide range of assays to be run simultaneously on the same cartridge using significantly reduced sample volumes with results in minutes.

A Novel Variant in G6PD (c.1375C>G) Identified from a Hispanic Neonate with Extreme Hyperbilirubinemia and Low G6PD Enzymatic Activity

We report a novel glucose-6-phosphate dehydrogenase (G6PD) variant (c.1375C>G) discovered in a 3-day-old Hispanic male child from Salt Lake City, UT, USA. This newborn presented with severe hyperbilirubinemia (29.8 mg/dL or 510 μmol/L) and marked hemolysis evidenced by elevated end-tidal carbon monoxide concentration (5.9 ppm, normal <1.7 ppm). Despite a very low prevalence of G6PD deficiency in Hispanic populations, we pursued testing for this condition and found he had low erythrocyte G6PD enzyme activity (2.8 U/g Hb, normal 9.9-16.6 U/g Hb) and a novel G6PD variant. His mother was heterozygous for this same variant, and she had a moderate decrease in G6PD enzyme activity (7.1 U/g Hb). On the basis of these findings, we propose this variant as a novel pathogenic mutation.

Chinese newborn screening for the incidence of G6PD deficiency and variant of G6PD gene from 2013 to 2017

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is one of the most common X-linked enzymopathies caused by G6PD gene variant. We aimed to provide the characteristics of G6PD deficiency and G6PD gene variant distribution in a large Chinese newborn screening population. We investigated the prevalence of G6PD in China from 2013 to 2017. Then, we examined G6PD activity and G6PD gene in representative Chinese birth cohort to explore the distribution of G6PD gene variant in 2016. We then performed multicolor melting curve analysis to classify G6PD gene variants in 10,357 neonates with activity-confirmed G6PD deficiency, and DNA Sanger sequencing for G6PD coding exons if hot site variants were not found. The screened population, organizations, and provinces of G6PD deficiency were increased from 2013 to 2017 in China. The top five frequency of G6PD gene variants were c.1376G>T, c.1388G>A, c.95A>G, c.1024C>T, and c.871G>A and varied in different provinces, with regional and ethnic features, and four pathogenic variant sites (c.152C>T, c.290A>T, c.697G>C, and c.1285A>G) were first reported. G6PD deficiency mainly occurs in South China, and the frequency of G6PD gene variant varies in different regions and ethnicities.

Health Considerations for Immigrant and Refugee Children

Immigrant and refugee children are at increased risk for physical, developmental, and behavioral health challenges. This article provides an overview of physical, developmental, and behavioral health considerations for immigrant and refugee children within an ecological framework that highlights family, community, and sociocultural influences. Experiences and exposures relevant to immigrant and refugee children are discussed. Clinical pearls are provided for topics of chronic disease, nutrition, infectious disease, developmental screening, and mental health assessment. Interdisciplinary and community partnerships are emphasized as a means to decrease barriers to care and facilitate family navigation of complex social, educational, and health care systems.

The association between glucose-6-phosphate dehydrogenase deficiency and abnormal blood pressure among prepregnant reproductive-age Chinese females

The morbidity of hypertension is increasing among young adults worldwide, and glucose-6-phosphate dehydrogenase (G6PD) deficiency is a high-prevalence genetic disease. We investigated whether G6PD deficiency was associated with abnormal blood pressure (including elevated blood pressure and hypertension) among prepregnant reproductive-age females. We conducted a cross-sectional study in Shenzhen, which included 154 917 females aged 20-49 who participated in the National Free Pre-conception Check-up Projects supported by the Chinese government. After adjusting for confounding factors, the odds ratios (ORs) for the effects of G6PD deficiency on elevated blood pressure and hypertension were 1.18 (95% confidence interval (CI): 1.03-1.35) and 1.11 (95% CI: 1.00-1.23), respectively. Moreover, the association between G6PD deficiency and abnormal blood pressure was statistically significant for systolic blood pressure (SBP) but not significant for diastolic blood pressure (DBP). The multivariable-adjusted ORs for females with G6PD deficiency in the SBP 120-139 mm Hg and SBP ≥ 140 mm Hg groups were 1.10 (95% CI: 1.00-1.21) and 1.75 (95% CI: 1.25-2.42), respectively, while the multivariable-adjusted ORs for females with G6PD deficiency in the DBP 80-89 mm Hg and DBP ≥ 90 mm Hg groups were 1.09 (95% CI: 0.98-1.21) and 0.89 (95% CI: 0.66-1.19), respectively. Subgroup analyses showed similar results. The findings of this study underscored that reproductive-age females with a G6PD deficiency had a higher risk of elevated blood pressure and hypertension. Therefore, females with G6PD deficiency combined with elevated blood pressure or hypertension were high-risk populations during prepregnancy and pregnancy periods. Early intervention and collaborative management approaches should be explored to reduce the burden of these two diseases and improve maternal and child health.

Indirect neonatal hyperbilirubinemia in hospitalized neonates on the Thai-Myanmar border: a review of neonatal medical records from 2009 to 2014

BACKGROUND

Indirect neonatal hyperbilirubinemia (INH) is a common neonatal disorder worldwide which can remain benign if prompt management is available. However there is a higher morbidity and mortality risk in settings with limited access to diagnosis and care. The manuscript describes the characteristics of neonates with INH, the burden of severe INH and identifies factors associated with severity in a resource-constrained setting.

METHODS

We conducted a retrospective evaluation of anonymized records of neonates hospitalized on the Thai-Myanmar border. INH was defined according to the National Institute for Health and Care Excellence guidelines as 'moderate' if at least one serum bilirubin (SBR) value exceeded the phototherapy threshold and as 'severe' if above the exchange transfusion threshold.

RESULTS

Out of 2980 records reviewed, 1580 (53%) had INH within the first 14 days of life. INH was moderate in 87% (1368/1580) and severe in 13% (212/1580). From 2009 to 2011, the proportion of severe INH decreased from 37 to 15% and the mortality dropped from 10% (8/82) to 2% (7/449) coinciding with the implementation of standardized guidelines and light-emitting diode (LED) phototherapy. Severe INH was associated with: prematurity (< 32 weeks, Adjusted Odds Ratio (AOR) 3.3; 95% CI 1.6-6.6 and 32 to 37 weeks, AOR 2.2; 95% CI 1.6-3.1), Glucose-6-phosphate dehydrogenase deficiency (G6PD) (AOR 2.3; 95% CI 1.6-3.3), potential ABO incompatibility (AOR 1.5; 95% CI 1.0-2.2) and late presentation (AOR 1.8; 95% CI 1.3-2.6). The risk of developing severe INH and INH-related mortality significantly increased with each additional risk factor.

CONCLUSION

INH is an important cause of neonatal hospitalization on the Thai-Myanmar border. Risk factors for severity were similar to previous reports from Asia. Implementing standardized guidelines and appropriate treatment was successful in reducing mortality and severity. Accessing to basic neonatal care including SBR testing, LED phototherapy and G6PD screening can contribute to improve neonatal outcomes.

Glucose-6-phosphate dehydrogenase deficiency in internationally adopted children

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

Genetics of HbA1c: a case study in clinical translation

Glycated hemoglobin (HbA1c) measures the amount of glucose in the blood in the previous 2-3 months and is used to test whether an individual has diabetes (HbA1c≥6.5%), or how well they are managing their diabetes. Genome-wide association studies have successfully identified multiple genomic loci influencing HbA1c, through both glycemic (factors that affect the amount blood glucose levels) and erythrocytic (factors that affect the red blood cell) pathways. Inaccuracies in HbA1c, due to non-glycemic variants, could lead to suboptimal care or adverse health consequences. A recently published example is the erythrocytic variant (rs1050828) in G6PD, which leads to the artificial lowering of HbA1c and missed diagnosis of diabetes using current thresholds. In this review we will discuss recent insights into the genetic etiology of HbA1c, and how these can translate to the clinic.

Diagnostic performances of the fluorescent spot test for G6PD deficiency in newborns along the Thailand-Myanmar border: A cohort study

Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited enzymatic disorder associated with severe neonatal hyperbilirubinemia and acute haemolysis after exposure to certain drugs or infections. The disorder can be diagnosed phenotypically with a fluorescent spot test (FST), which is a simple test that requires training and basic laboratory equipment. This study aimed to assess the diagnostic performances of the FST used on umbilical cord blood by locally-trained staff and to compare test results of the neonates at birth with the results after one month of age.

Methods: We conducted a cohort study on newborns at the Shoklo Malaria Research Unit, along the Thai-Myanmar border between January 2015 and May 2016. The FST was performed at birth on the umbilical cord blood by locally-trained staff and quality controlled by specialised technicians at the central laboratory. The FST was repeated after one month of age. Genotyping for common local G6PD mutations was carried out for all discrepant results.

Results: FST was performed on 1521 umbilical cord blood samples. Quality control and genotyping revealed 10 misdiagnoses. After quality control, 10.7% of the males (84/786) and 1.2% of the females (9/735) were phenotypically G6PD deficient at birth. The FST repeated at one month of age or later diagnosed 8 additional G6PD deficient infants who were phenotypically normal at birth.

Conclusions: This study shows the short-comings of the G6PD FST in neonatal routine screening and highlights the importance of training and quality control. A more conservative interpretation of the FST in male newborns could increase the diagnostic performances. Quantitative point-of-care tests might show higher sensitivity and specificity for diagnosis of G6PD deficiency on umbilical cord blood and should be investigated.

Point-of-Care Testing for G6PD Deficiency: Opportunities for Screening

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, an X-linked genetic disorder, is associated with increased risk of jaundice and kernicterus at birth. G6PD deficiency can manifest later in life as severe hemolysis, when the individual is exposed to oxidative agents that range from foods such as fava beans, to diseases such as typhoid, to medications such as dapsone, to the curative drugs for Plasmodium (P.) vivax malaria, primaquine and tafenoquine. While routine testing at birth for G6PD deficiency is recommended by the World Health Organization for populations with greater than 5% prevalence of G6PD deficiency and to inform P. vivax case management using primaquine, testing coverage is extremely low. Test coverage is low due to the need to prioritize newborn interventions and the complexity of currently available G6PD tests, especially those used to inform malaria case management. More affordable, accurate, point-of-care (POC) tests for G6PD deficiency are emerging that create an opportunity to extend testing to populations that do not have access to high throughput screening services. Some of these tests are quantitative, which provides an opportunity to address the gender disparity created by the currently available POC qualitative tests that misclassify females with intermediate G6PD activity as normal. In populations where the epidemiology for G6PD deficiency and P. vivax overlap, screening for G6PD deficiency at birth to inform care of the newborn can also be used to inform malaria case management over their lifetime.

Glucose-6-phosphate dehydrogenase enzyme stability in filter paper dried blood spots

OBJECTIVE

Prior to initial distribution of Glucose-6-phosphate dehydrogenase (G6PD) proficiency testing (PT) materials, we evaluated G6PD enzyme stability in dried blood spots (DBS) under various temperature and humidity environments to develop storage and usage guidelines for our new materials.

DESIGN & METHODS

We prepared fresh G6PD-normal DBS materials and conducted stability evaluations of daily use and short and long-term storage under various temperature and humidity environments.

RESULTS

G6PD DBS PT materials retained 92% of initial activity after 30days of use at 4°C. Materials stored at -20°C and 4°C with desiccant for 30days retained 95% and 90% of initial activity, respectively. When stored for one year at -20°C or six months at 4°C specimens retained >90% of initial activity. Specimens stored at 37°C with desiccant lost 10% activity in three days. At the end of 30days, specimens stored under 'Extreme'-humidity >50% without desiccant- conditions at 37°C assayed below the NSQAP cut off for G6PD. Humidity exacerbated loss of enzyme activity with increasing temperature and time duration.

CONCLUSION

Data suggest that G6PD PT materials can be stored at 4°C and used for up to one month and can be stored at -20°C for one year and yield >90% enzyme activity. Exposure to warm temperatures, especially with elevated humidity, should be avoided. Desiccant should always be used to mitigate humidity effects.

Impact of common genetic determinants of Hemoglobin A1c on type 2 diabetes risk and diagnosis in ancestrally diverse populations: A transethnic genome-wide meta-analysis

BACKGROUND

Glycated hemoglobin (HbA1c) is used to diagnose type 2 diabetes (T2D) and assess glycemic control in patients with diabetes. Previous genome-wide association studies (GWAS) have identified 18 HbA1c-associated genetic variants. These variants proved to be classifiable by their likely biological action as erythrocytic (also associated with erythrocyte traits) or glycemic (associated with other glucose-related traits). In this study, we tested the hypotheses that, in a very large scale GWAS, we would identify more genetic variants associated with HbA1c and that HbA1c variants implicated in erythrocytic biology would affect the diagnostic accuracy of HbA1c. We therefore expanded the number of HbA1c-associated loci and tested the effect of genetic risk-scores comprised of erythrocytic or glycemic variants on incident diabetes prediction and on prevalent diabetes screening performance. Throughout this multiancestry study, we kept a focus on interancestry differences in HbA1c genetics performance that might influence race-ancestry differences in health outcomes.

METHODS & FINDINGS

Using genome-wide association meta-analyses in up to 159,940 individuals from 82 cohorts of European, African, East Asian, and South Asian ancestry, we identified 60 common genetic variants associated with HbA1c. We classified variants as implicated in glycemic, erythrocytic, or unclassified biology and tested whether additive genetic scores of erythrocytic variants (GS-E) or glycemic variants (GS-G) were associated with higher T2D incidence in multiethnic longitudinal cohorts (N = 33,241). Nineteen glycemic and 22 erythrocytic variants were associated with HbA1c at genome-wide significance. GS-G was associated with higher T2D risk (incidence OR = 1.05, 95% CI 1.04-1.06, per HbA1c-raising allele, p = 3 × 10-29); whereas GS-E was not (OR = 1.00, 95% CI 0.99-1.01, p = 0.60). In Europeans and Asians, erythrocytic variants in aggregate had only modest effects on the diagnostic accuracy of HbA1c. Yet, in African Americans, the X-linked G6PD G202A variant (T-allele frequency 11%) was associated with an absolute decrease in HbA1c of 0.81%-units (95% CI 0.66-0.96) per allele in hemizygous men, and 0.68%-units (95% CI 0.38-0.97) in homozygous women. The G6PD variant may cause approximately 2% (N = 0.65 million, 95% CI 0.55-0.74) of African American adults with T2D to remain undiagnosed when screened with HbA1c. Limitations include the smaller sample sizes for non-European ancestries and the inability to classify approximately one-third of the variants. Further studies in large multiethnic cohorts with HbA1c, glycemic, and erythrocytic traits are required to better determine the biological action of the unclassified variants.

CONCLUSIONS

As G6PD deficiency can be clinically silent until illness strikes, we recommend investigation of the possible benefits of screening for the G6PD genotype along with using HbA1c to diagnose T2D in populations of African ancestry or groups where G6PD deficiency is common. Screening with direct glucose measurements, or genetically-informed HbA1c diagnostic thresholds in people with G6PD deficiency, may be required to avoid missed or delayed diagnoses.

Glucose-6-Phosphate Dehydrogenase Deficiency and the Need for a Novel Treatment to Prevent Kernicterus

Hyperbilirubinemia occurs frequently in newborns, and in severe cases can progress to kernicterus and permanent developmental disorders. Glucose-6-phosphate dehydrogenase (G6PD) deficiency, one of the most common human enzymopathies, is a major risk factor for hyperbilirubinemia and greatly increases the risk of kernicterus even in the developed world. Therefore, a novel treatment for kernicterus is needed, especially for G6PD-deficient newborns. Oxidative stress is a hallmark of bilirubin toxicity in the brain. We propose that the activation of G6PD via a small molecule chaperone is a potential strategy to increase endogenous defense against bilirubin-induced oxidative stress and prevent kernicterus.

The Preterm Infant: A High-Risk Situation for Neonatal Hyperbilirubinemia Due to Glucose-6-Phosphate Dehydrogenase Deficiency

Prematurity and glucose-6-phosphate dehydrogenase (G6PD) deficiency are risk factors for neonatal hyperbilirubinemia. The 2 conditions may interact additively or synergistically, contributing to extreme hyperbilirubinemia, with the potential for bilirubin neurotoxicity. This hyperbilirubinemia is the result of sudden, unpredictable, and acute episodes of hemolysis in combination with immaturity of bilirubin elimination, primarily of conjugation. Avoidance of contact with known triggers of hemolysis in G6PD-deficient individuals will prevent some, but not all, episodes of hemolysis. All preterm infants with G6PD deficiency should be vigilantly observed for the development of jaundice both in hospital and after discharge home.

National G6PD neonatal screening program in Gaza Strip of Palestine: rationale, challenges and recommendations

Congenital genetic disorders affecting neonates or young children can have serious clinical consequences if undiagnosed and left untreated. Early detection and an accurate diagnosis are, therefore, of major importance for preventing negative patient outcomes. Even though the occurrence of each specific metabolic disorder may be rare, their collective impact of preventable complications may be of considerable importance to the public health. Our previous studies showed that glucose-6-phosphate dehydrogenase (G6PD) deficiency is a problem of public health importance that has been shown to be a predominant cause of acute hemolytic anemia requiring hospitalization in Palestinian young children in Gaza Strip. Intriguingly, the majority of these children had one of the three variants, Mediterranean(c.) (563T) , African G6PD A-(c.) (202A) (/c.) (376G) and heretofore unrecognized as a common G6PD-deficient variant G6PD Cairo(c.) (404C) . The high prevalence of G6PD deficiency, as well as dietary factors in the region that precipitate anemia, argues for a need to protect the Palestinian children from a treatable and manageable genetic and metabolic disorder. This work reviews and discusses rationales and challenges of G6PD screening program in Gaza Strip. We advocate adopting a national neonatal G6PD screening program in Gaza Strip to identify children at risk and promote wellness and health for Palestine.

Identification of neonatal haemolysis: an approach to predischarge management of neonatal hyperbilirubinemia

AIM

Relative contributions of increased production [by end-tidal carbon monoxide concentrations (ETCOc)] and decreased elimination of bilirubin to predischarge hour-specific total bilirubin (TB) levels were assessed in healthy late-preterm and term newborns. Secondly, we report predischarge ETCOc ranges to guide clinical management of hyperbilirubinemia.

METHODS

TB and ETCOc (≤3 timepoints) determinations of newborns aged between six hours and <6 days (n = 79) were stratified by postnatal age epochs. Hyperbilirubinemia risk was assessed by plotting TB values as a function of ETCOc.

RESULTS

Stratifications of ETCOc (in ppm, mean, median and interquartile ranges) by postnatal age epochs (0-24, 24-48 and 48-72) were as follows: 2.0, 1.9, 1.8-2.2 (n = 11); 1.6, 1.5, 1.1-2.0 (n = 58); and 2.0, 1.8, 1.6-2.3 (n = 9), respectively. Infants with ETCOc ≥ 2.5 were at high risk, between 1.5 and 2.5 at moderate risk and ≤1.5 were at low risk. Risk due to haemolysis alone was not independent (p < 0.01). For infants with TB >75th percentile (n = 31), 23% had ETCO ≤1.5, and 77% had ETCOc > 1.5 (p < 0.00003).

CONCLUSION

Near-simultaneous ETCOc and TB measurements in infants with TB >75th percentile accurately identify haemolytic hyperbilirubinemia.

Assessment of G6PD screening program in premature infants in a NICU

OBJECTIVE

Targeted screening for glucose-6-phosphate dehydrogenase deficiency (G6PDdef) using fluorescent spot test (FST) is done in our newborn nursery (NN) and now in our NICU. Premature infants have higher G6PD levels than term infants. FST may result in under diagnosis of G6PDdef in preterms. We sought to determine if FST is appropriate for diagnosis of G6PDdef at<35 weeks and assess screening in NICU.

STUDY DESIGN

Retrospective chart review of male, inborn infants<35 weeks in NICU from 2008 to 2011. Difference in G6PDdef incidence<5% between NN and NICU was acceptable for equivalence.

RESULTS

Out of 679 subjects, 442 were screened for G6PDdef and 11.3% had abnormal results. Binomial testing comparing 11.3% (95% confidence interval (CI) 8.5 to 14.6) incidence of G6PDdef in NICU and reported incidence in NN (11%) demonstrated no difference. 12.2% of Black/African American males were not screened.

CONCLUSION

FST is appropriate for screening all at-risk newborns. A number of at-risk premature males were not screened.

Point-of-Care Quantitative Measure of Glucose-6-Phosphate Dehydrogenase Enzyme Deficiency

BACKGROUND AND OBJECTIVES

Widespread newborn screening on a point-of-care basis could prevent bilirubin neurotoxicity in newborns with glucose-6-phosphate dehydrogenase (G6PD) deficiency. We evaluated a quantitative G6PD assay on a digital microfluidic platform by comparing its performance with standard clinical methods.

METHODS

G6PD activity was measured quantitatively by using digital microfluidic fluorescence and the gold standard fluorescence biochemical test on a convenience sample of 98 discarded blood samples. Twenty-four samples were designated as G6PD deficient.

RESULTS

Mean ± SD G6PD activity for normal samples using the digital microfluidic method and the standard method, respectively, was 9.7 ± 2.8 and 11.1 ± 3.0 U/g hemoglobin (Hb), respectively; for G6PD-deficient samples, it was 0.8 ± 0.7 and 1.4 ± 0.9 U/g Hb. Bland-Altman analysis determined a mean difference of -0.96 ± 1.8 U/g Hb between the digital microfluidic fluorescence results and the standard biochemical test results. The lower and upper limits for the digital microfluidic platform were 4.5 to 19.5 U/g Hb for normal samples and 0.2 to 3.7 U/g Hb for G6PD-deficient samples. The lower and upper limits for the Stanford method were 5.5 to 20.7 U/g Hb for normal samples and 0.1 to 2.8 U/g Hb for G6PD-deficient samples. The measured activity discriminated between G6PD-deficient samples and normal samples with no overlap.

CONCLUSIONS

Pending further validation, a digital microfluidics platform could be an accurate point-of-care screening tool for rapid newborn G6PD screening.

Parental education and the WHO neonatal G-6-PD screening program: a quarter century later

Neonatal screening for glucose-6-phosphate dehydrogenase (G-6-PD) deficiency in any population with a male frequency >3-5%, combined with parental education regarding the dietary, environmental and sepsis-related triggers for hemolysis was recommended by the WHO (World Health Organization) Working Group in 1989. As the aim of identifying G-6-PD deficiency in the newborn period is to avert or detect extreme hyperbilirubinemia developing at home, before the development of kernicterus, the parental role in identifying evolving icterus was considered integral to any screening program. Now, a quarter century after publication of this report, severe bilirubin neurotoxicity associated with G-6-PD deficiency continues to be encountered worldwide. Screening programs have not been universally introduced but several national or regional maternal child health programs have implemented neonatal G-6-PD screening. Some reports detail the role of parental education, based on the above mentioned principles, through a variety of audio-visual materials. The paucity of randomized controlled trials or validated evidence to demonstrate the effectiveness of the contribution of parental education fails to meet the ideal testable evidence-based approach. However, our review of the cumulative experience and evidence currently available does supply certain information reflecting a positive impact of screening programs combined with parental input. We propose that the current information is sufficient to continue to support and apply the Working Group's recommendations. In order not to waste unnecessary time available, data may be used in lieu of randomized trials to continue to recommend screening programs, as suggested, in high-risk regions. If the incidence of kernicterus associated with G-6-PD deficiency is to be diminished, G-6-PD screening in combination with parental explanation may be one instance in which the consensus approach suggested by the WHO Working Group, rather than reliance on (nonexistent) evidence-based studies, should continue to be practiced.

Pediatric Provider Insight Into Newborn Screening for Glucose-6-Phosphate Dehydrogenase Deficiency

OBJECTIVE

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a major contributor to neonatal hyperbilirubinemia, yet newborn screening for this disorder in the United States is not standard practice. We surveyed pediatric providers regarding a novel newborn G6PD screening program successfully implemented in 2007 at a US urban women's hospital newborn nursery.

STUDY DESIGN

An electronic survey was distributed to 472 pediatric providers addressing extent to which they were influenced by the screening program.

RESULTS

Ninety-two (20%) providers responded, of whom 74 (80%) had taken care of G6PD-deficient patients diagnosed by the screening program. A majority found the diagnosis helpful for patient management and influential in their management. Most common changes in management included more counseling on jaundice and follow-up and avoidance of hemolytic crisis triggers.

CONCLUSIONS

General pediatric providers support newborn G6PD screening and appreciate the current program. Knowing the G6PD deficiency status of newborns informed and influenced pediatric providers' care.

Common hematologic problems in the newborn nursery

"Common red blood cell disorders encountered in the normal newborn nursery include hemolytic disease of the newborn and resultant hyperbilirubinemia, anemia, and polycythemia. A less frequent clinically relevant hematologic issue in newborns to be covered herein is thrombocytopenia."

Newborn screening: need of the hour in India

After a review of the current health scene in India, the authors suggest that the Government of India should consider seriously, the introduction of new born screening. As a first step, a central advisory committee should be constituted to recommend what is required to be done to strengthen the infrastructure and the manpower to carry out new born screening, and the disorders to be screened. In the urban hospitals newborn screening (NBS) for three disorders can be easily introduced (congenital hypothyroidism, congenital adrenal hyperplasia and G-6-PD deficiency), while in the rural areas this should begin with congenital hypothyroidism, especially in the sub Himalayan areas. Concurrently, logistic issues regarding diets and special therapies for inborn errors of metabolism should be sorted out, laboratories to confirm the diagnosis should be set up, and a cadre of metabolic physicians should be build up to treat those identified to have inborn errors of metabolism. Once these are established on a firm footing, tandem mass spectrometry should be introduced as it allows the identification of a number of disorders in an affordable manner. The recent improvements and current trends in health care in India have created the necessary infrastructure for adopting NBS for the benefit of infants in India.

Hyperbilirubinemia, hemolysis, and increased bilirubin neurotoxicity

Increased hemolysis in the presence of severe neonatal hyperbilirubinemia appears to augment the risk of bilirubin neurotoxicity. The mechanism of this intensifying effect is uncertain. In direct antiglobulin titer (DAT) positive, isoimmune hemolytic disease, the bilirubin threshold at which neurotoxicity occurs appears to be lower than in DAT-negative hyperbilirubinemia. In other hemolytic conditions, the hemolysis may simply facilitate the development of extremely high serum bilirubin levels. Whether the hemolytic process per se exerts an independent effect or whether a very rapid rise in serum bilirubin might lead to greater penetration of the blood-brain barrier is unclear. In this review, we survey the synergistic role of hemolysis associated with severe hyperbilirubinemia in the potentiation of bilirubin-induced neurotoxicity and suggest methods of identifying at-risk babies with increased hemolysis to allow for their increased surveillance.

Incidence, etiology, and outcomes of hazardous hyperbilirubinemia in newborns

BACKGROUND AND OBJECTIVES

Total serum bilirubin (TSB) levels ≥ 30 mg/dL are rare but potentially hazardous. A better understanding of their incidence, causes, and outcomes could help inform preventive efforts.

METHODS

We identified infants born ≥ 35 weeks' gestational age from 1995-2011 in Kaiser Permanente Northern California (n = 525409) and examined the medical records of infants with a TSB ≥ 30 mg/dL to determine etiology and the occurrence of acute bilirubin encephalopathy. We reviewed inpatient and outpatient encounters through 2013 for evidence of sensorineural hearing loss (SNHL) or cerebral palsy (CP).

RESULTS

We identified 47 infants with TSB ≥ 30 mg/dL (8.6 per 100000 births). In 44 infants (94%), the hyperbilirubinemia occurred after the initial birth hospitalization. The etiology was not identified in 33 (70%). Glucose-6-phosphate dehydrogenase (G6PD) activity was measured in only 25 (53%) of whom 10 (40%) were deficient. Four children had acute bilirubin encephalopathy of whom 2 developed both CP and SNHL, and 1 developed isolated SNHL. These 3 infants all had G6PD deficiency and TSB >40 mg/dL. One additional 35-week infant with TSB 38.2 mg/dL had SNHL.

CONCLUSIONS

Hazardous (≥ 30 mg/dL) hyperbilirubinemia is a rare event. No etiology could be identified from the clinical record in most cases. G6PD deficiency was the leading cause of hazardous hyperbilirubinemia when an etiology was identified, but many were not tested. Chronic, bilirubin-induced neurotoxicity was uncommon and occurred only in the setting of additional risk factors and TSB values well over (>15 mg/dL) the American Academy of Pediatrics exchange transfusion thresholds.

Causes of hemolysis in neonates with extreme hyperbilirubinemia

OBJECTIVE

We instituted a quality improvement process to enhance our capacity to diagnose genetic hemolytic conditions in neonates with extreme hyperbilirubinemia.

STUDY DESIGN

During a 1-year period, whenever the total serum bilirubin (TSB) was >25 mg dl(-1) a special evaluation was performed. If we deemed an erythrocyte membrane defect likely, based on red blood cell morphology, EMA-flow cytometry was performed. Otherwise 'next-generation' sequencing was performed using a panel of genes involved in neonatal hyperbilirubinemia.

RESULT

Ten neonates had a TSB ⩾ 25 mg dl(-1). Two others were evaluated as part of this process at the request of their attending neonatologists, because each had a TSB >14 mg dl(-1) in the first hours after birth and required phototherapy for ⩾ 1 week. Explanations for the jaundice were found in all 12 neonates. Five had hereditary spherocytosis, three of which also had ABO hemolytic disease. Two had pyruvate kinase deficiency. One had severe G6PD deficiency. The other four had ABO hemolytic disease.

CONCLUSION

On the basis of the present small case series, we suggest that among neonates with extreme hyperbilirubinemia, it can be productive to pursue a genetic basis for hemolytic disease.

Prevention of Kernicterus in South Asia: role of neonatal G6PD deficiency and its identification

Extreme hyperbilirubinemia (EHB) caused by neonatal glucose-6-phosphate dehydrogenase (G6PD) deficiency is strongly associated with mortality and long-term neurodevelopmental impairment, yet there are limited national strategies to reduce this burden in South Asia. Current known and predicted prevalence of G6PD deficiency in Afghanistan, Bangladesh, Bhutan, India, Nepal, and Pakistan ranges from 3.8 to 15 %, with regional "hot spots" exceeding 22 %. Annually, 3.14 million infants are born at risk for this condition. In 2010, South Asian countries reported 37 million (27 %) of world-wide livebirths ≥ 32 wk gestational-age and G6PD deficiency accounted for > 33 % of the global EHB burden, in contrast to 2.2 % for those born in high-income nations. Traditional national approach includes universal newborn screening in malaria-endemic countries or those with prevalence >3.5 %. However, screening implementation should be best optimized using timely quantitative enzyme assay and identification of at-risk female newborns. Furthermore, economic and social constraints, in context of sub-regional variances, call for flexible problem-solving methods in anticipation of changing community demographics. Thus, incremental and need-based newborn screening programs could be the most optimal approach. A human-centered design (HCD) approach, as an alternate pathway, could build the evidence to translate the complex biology of G6PD deficiency and the biodesign of affordable technologies, allowing facilitation of access to knowledge and services, in order to deliver on a long-term public health mandate. Key steps would encompass the initiation of local inquiry of both quantitative and qualitative data to identify at-risk communities and to prospectively design for local innovative solutions.