History and current status of newborn screening for hemoglobinopathies

Medicaid Coverage in Early Childhood for Children With Sickle Cell Disease

This cohort study examines patterns of Medicaid coverage in the first 3 years of life among children with sickle cell disease across 5 states.

Sickle Cell Screening in Adults: A Current Review of Point-of-Care Testing

In adults, the sickle cell solubility test (SCST) is the most common screening test to determine the presence of hemoglobin S (HbS) within a blood sample. The assay is inexpensive, rapid, highly sensitive and specific. However, the SCST cannot accurately quantify the level of HbS in a test sample and requires confirmatory testing to distinguish between sickle trait and sickle cell disease. Despite these limitations, it remains the standard screening tool for HbS in a variety of settings such as screening in the US military or by the National Collegiate Athletic Association. With an increased awareness of the importance of screening for sickle cell in adults, we herein describe the current sensitivity, specificity, positive predictive value, and negative predictive value of this test. We also review overall clinical utility of this laboratory measure and briefly discuss new point-of-care techniques designed to overcome the SCST's shortcomings.

Evaluating ApoL1 Genetic Testing Policy Options for Transplant Centers: A Delphi Consensus Panel Project with Stakeholders

BACKGROUND

Apolipoprotein L1 (ApoL1) variants G1 and G2 are associated with a higher risk of kidney disease. ApoL1 risk variants are predominantly seen in individuals with sub-Saharan African ancestry. In most transplant centers, potential organ donors are being selectively genetically tested for ApoL1 risk variants. Transplant programs have highly variable ApoL1 testing practices and need guidance on essential ApoL1 clinical policy questions.

METHODS

We conducted a Delphi consensus panel focused on ApoL1 clinical policy questions, including who gets tested, who decides whether testing occurs, how test results are shared, who receives test results, and how test results are used. A total of 27 panelists across seven stakeholder groups participated: living kidney donors ( n =4), deceased donor family members ( n =3), recipients of a deceased donor kidney ( n =4), recipients of a living donor kidney ( n =4), nephrologists ( n =4), transplant surgeons ( n =4), and genetic counselors ( n =4). Nineteen panelists (70%) identified as Black. The Delphi panel process involved two rounds of educational webinars and three rounds of surveys administered to panelists, who were asked to indicate whether they support, could live with, or oppose each policy option.

RESULTS

The panel reached consensus on one or more acceptable policy options for each clinical policy question; panelists supported 18 policy options and opposed 15. Key elements of consensus include the following: ask potential donors about African ancestry rather than race; make testing decisions only after discussion with donors; encourage disclosure of test results to blood relatives and organ recipients but do not require it; use test results to inform decision making, but never for unilateral decisions by transplant programs.

CONCLUSIONS

The panel generally supported policy options involving discussion and shared decision making among patients, donors, and family stakeholders. There was general opposition to unilateral decision making and prohibiting donation altogether.

Birth Prevalence of Sickle Cell Disease and County-Level Social Vulnerability - Sickle Cell Data Collection Program, 11 States, 2016-2020

Sickle cell disease (SCD) remains a public health priority in the United States because of its association with complex health needs, reduced life expectancy, lifelong disabilities, and high cost of care. A cross-sectional analysis was conducted to calculate the crude and race-specific birth prevalence for SCD using state newborn screening program records during 2016-2020 from 11 Sickle Cell Data Collection program states. The percentage distribution of birth mother residence within Social Vulnerability Index quartiles was derived. Among 3,305 newborns with confirmed SCD (including 57% with homozygous hemoglobin S or sickle β-null thalassemia across 11 states, 90% of whom were Black or African American [Black], and 4% of whom were Hispanic or Latino), the crude SCD birth prevalence was 4.83 per 10,000 (one in every 2,070) live births and 28.54 per 10,000 (one in every 350) non-Hispanic Black newborns. Approximately two thirds (67%) of mothers of newborns with SCD lived in counties with high or very high levels of social vulnerability; most mothers lived in counties with high or very high levels of vulnerability for racial and ethnic minority status (89%) and housing type and transportation (64%) themes. These findings can guide public health, health care systems, and community program planning and implementation that address social determinants of health for infants with SCD. Implementation of tailored interventions, including increasing access to transportation, improving housing, and advancing equity in high vulnerability areas, could facilitate care and improve health outcomes for children with SCD.

Case Ascertainment of Sickle Cell Disease Using Surveillance or Single Administrative Database Case Definitions

OBJECTIVE

In the absence of access to surveillance system data, single-source administrative databases are often used to study health care utilization and health outcomes among people with sickle cell disease (SCD). We compared the case definitions from single-source administrative databases with a surveillance case definition to identify people with SCD.

MATERIALS AND METHODS

We used data from Sickle Cell Data Collection programs in California and Georgia (2016-2018). The surveillance case definition for SCD developed for the Sickle Cell Data Collection programs uses multiple databases, including newborn screening, discharge databases, state Medicaid programs, vital records, and clinic data. Case definitions for SCD in single-source administrative databases varied by database (Medicaid and discharge) and years of data (1, 2, and 3 years). We calculated the proportion of people meeting the surveillance case definition for SCD that was captured by each single administrative database case definition for SCD, by birth cohort, sex, and Medicaid enrollment.

RESULTS

In California, 7117 people met the surveillance case definition of SCD from 2016 through 2018; 48% of this group was captured by the Medicaid case definition and 41% by the discharge case definition. In Georgia, 10 448 people met the surveillance case definition of SCD from 2016 through 2018; 45% of this group was captured by the Medicaid case definition and 51% by the discharge case definition. These proportions differed by years of data, birth cohort, and length of Medicaid enrollment.

PRACTICE IMPLICATIONS

The surveillance case definition identified twice as many people with SCD as the single-source administrative database definitions during the same period, but trade-offs exist in using single administrative databases for decisions on policy and program expansion for SCD.

Optimising the screening for haemoglobinopathies in pregnancy planning

Haemoglobinopathies are among the most common inherited disorders around the world. In the United States the diagnosis of haemoglobinopathy or a carrier state is made by universal newborn screening. However, many individuals of childbearing age do not know they are a haemoglobinopathy carrier. Screening for common haemoglobinopathies is generally offered as a part of pregnancy planning so that prospective parents can be counselled regarding the risk of having a child with a haemoglobinopathy. Multiple tests exist to screen patients for presence of haemoglobinopathy carrier or disease state; however, it is crucial to order and interpret the results correctly to appropriately counsel couples. In this case series, we describe clinical scenarios where prospective parents were surprised to unexpectedly have a child with sickle cell disease, a haemoglobinopathy that causes severe clinical complications. Through these cases we demonstrate that deficiencies in testing can occur at different levels which may lead to incorrect estimation of the risk of having a child affected by a haemoglobinopathy. Consultation with a haematologist, laboratory medicine specialist, or genetic counsellor should be considered to select the appropriate test and interpret its results.

Attitudes and beliefs regarding race-targeted genetic testing of Black people: A systematic review

Geographical ancestry has been associated with an increased risk of various genetic conditions. Race and ethnicity often have been used as proxies for geographical ancestry. Despite numerous problems associated with the crude reliance on race and ethnicity as proxies for geographical ancestry, some genetic testing in the clinical, research, and employment settings has been and continues to be race- or ethnicity-based. Race-based or race-targeted genetic testing refers to genetic testing offered only or primarily to people of particular racial or ethnic groups because of presumed differences among groups. One current example is APOL1 testing of Black kidney donors. Race-based genetic testing raises numerous ethical and policy questions. Given the ongoing reliance on the Black race in genetic testing, it is important to understand the views of people who identify as Black or are identified as Black (including African American, Afro-Caribbean, and Hispanic Black) regarding race-based genetic testing that targets Black people because of their race. We conducted a systematic review of studies and reports of stakeholder-engaged projects that examined how people who identify as or are identified as Black perceive genetic testing that specifically presumes genetic differences exist among racial groups or uses race as a surrogate for ancestral genetic variation and targets Black people. Our review identified 14 studies that explicitly studied this question and another 13 that implicitly or tacitly studied this matter. We found four main factors that contribute to a positive attitude toward race-targeted genetic testing (facilitators) and eight main factors that are associated with concerns regarding race-targeted genetic testing (barriers). This review fills an important gap. These findings should inform future genetic research and the policies and practices developed in clinical, research, public health, or other settings regarding genetic testing.

Clinical Classification, Screening, and Diagnosis in Beta-Thalassemia and Hemoglobin E/Beta-Thalassemia

This article reviews the classification of beta-thalassemia syndromes, correlating clinical severity and genotype in the earlier classification, and broadening it recently based on clinical severity and transfusion status. The classification is dynamic, and individuals may progress from transfusion-independent to transfusion-dependent. Early and accurate diagnosis prevents delays in instituting treatment and comprehensive care, and precludes inappropriate and potentially harmful interventions. Screening can inform risk in an individual and subsequent generations when partners may be carriers as well. This article discusses the rationale for screening of the at-risk population. In the developed world, a more precise genetic diagnosis must be considered.

Sudden Death in Diabetic Ketoacidosis Complicated by Sickle Cell Trait

ABSTRACT

In a sudden death investigation of a service member with sickle cell trait (SCT), evidence of sickle cell crisis further complicated by coexisting, undiagnosed diabetic ketoacidosis called into question the synergistic effects of diabetic ketoacidosis on red blood cell sickling. Sickle cell trait affects more than 4 million people in the United States (US) with the highest prevalence in non-Hispanic Blacks (7%-9%; Mil Med 2017;182(3):e1819-e1824). The heterozygous state of sickled hemoglobin was previously considered a benign condition causing sickling during hypoxic, high-stress conditions such as exercise and high altitude ( Am Assoc Clin Chem 2017). However, research within the last decade shows evidence of sudden death among SCT patients ( J Forensic Sci 2011;56(5):1352-1360). It has been shown that the presence of sickled hemoglobin artificially lowers levels of hemoglobin A1c making it a less effective biomarker for red blood cell glycosylation over time in sickle cell patients ( JAMA 2017;317(5):507-515). The limited scope of medical understanding of the effects of SCT in combination with other comorbidities requires further investigation and better diagnostic criteria. The uniqueness of the US Military and its screening program for sickle cell disease (SCD) and SCT allows for more detection. Since May 2006, newborn screening for SCD/SCT has been a national requirement; however, anyone older than 14 years may not know their SCD/SCT status ( Semin Perinatol 2010;34(2):134-44). The previous absence of such national screening makes it more challenging to identify SCT and SCD patients even within high-risk populations. Furthermore, patients may not know or understand the results of their SCD/SCT status testing. International standards for the autopsy of decedents with SCD and SCT exist ( R Coll Pathol 2017). Within the US, testing of vitreous electrolytes is a common practice in suspected natural death cases, but a review of the US literature did not demonstrate any autopsy standards or recommendations for persons with SCT or high-risk persons for sickling pathologies. The identification of a new diagnosis of type 2 diabetes mellitus, as the cause of death, is not uncommon; however, this case indicates that type 2 diabetes mellitus was not the sole contributing factor. It further illustrates that the US may be underestimating the impact of SCD and SCT as a cause of death, a contributing factor to death, and its synergistic effects with other pathologic processes. We propose a stringent literature review in conjunction with a review of international autopsy standards to develop national autopsy standards and possible SCT/SCD screening recommendations for high-risk persons at the time of autopsy.

Sickle Cell Trait and Risk for Common Diseases: Evidence from the UK Biobank

BACKGROUND

Sickle cell trait is typically considered benign. Although evidence remains inconsistent, recent studies suggest that it is associated with several common diseases. We systematically assessed associations of sickle cell trait with reported diseases in a large population-based cohort.

METHODS

Study subjects were self-reported Blacks from the UK Biobank (UKB), a United Kingdom population-based cohort of subjects aged 40-69 years at recruitment in the United Kingdom. Sickle cell status was based on the International Classification of Diseases, Tenth Revision (ICD-10) or mutations in the HBB gene. Diagnoses of diseases were obtained from ICD-10 and self-reports. Associations of sickle cell trait and diseases were tested using logistic regression, adjusting for age at recruitment, sex, and genetic background (top 10 principal components).

RESULTS

Among the 8019 Blacks in the UKB, 699 (8.72%) were sickle cell trait carriers; the rate was significantly higher in females (9.74%) than males (7.48%), P = .0005. Sickle cell trait was under-diagnosed; most heterozygous hemoglobin subunit beta (HBB) gene Glu6Val carriers did not have a sickle cell trait ICD-10 record. Compared with non-sickle cell trait, sickle cell trait carriers had significantly increased risk for type 2 diabetes; odds ratio 1.38; 95% confidence interval, 1.12-1.68; P = .002. Sickle cell trait was also significantly associated with increased risk for renal diseases (rhabdomyolysis, end-stage renal disease, chronic kidney disease, renal papillary necrosis) and vascular diseases (hypertension, retinopathy, non-ischemic stroke), P < .05. While most of these diseases are complications/comorbidities of diabetes, their associations with sickle cell trait remained significant after adjusting for diabetes. Association with end-stage renal disease was stronger in subjects without diabetes, odds ratio 6.45; 95% confidence interval, 1.93-19.61; P = .001.

CONCLUSIONS

Sickle cell trait is significantly associated with increased risk for diabetes and diabetes-related complications/comorbidities.

Strategies to increase access to basic sickle cell disease care in low- and middle-income countries

INTRODUCTION

Sickle cell disease (SCD) is the most common hemoglobinopathy in the world. Over 90% of those born with SCD live in low- and middle-income countries (LMICs), yet individuals in these settings have much poorer outcomes compared to those in high-income countries.

AREAS COVERED

This manuscript provides an in-depth review of the cornerstones of basic SCD care, the barriers to implementing these in LMICs, and strategies to increase access in these regions. Publications in English language, peer-reviewed, and edited from 2000 to 2021 were identified on PubMed. Google search was used for gray literature.

EXPERT OPINION

Outcomes for patients with SCD in high-income countries have improved over the last few decades due to the implementation of universal newborn screening programs and use of routine antimicrobial prophylaxis, increase in therapeutic and curative options, and the adoption of specific measures to decrease risk of stroke. This success has not translated to LMICs due to several reasons including resource constraints. A combination of several strategies is needed to increase access to basic SCD care for patients in these settings.

Enablers and barriers to newborn screening for sickle cell disease in Africa: results from a qualitative study involving programmes in six countries

OBJECTIVES

Given the fundamental role of newborn bloodspot screening (NBS) to enable prompt diagnosis and optimal clinical management of individuals with sickle cell disease (SCD), we sought to systematically assess enablers and barriers to implementation of NBS programmes for SCD in Africa using established qualitative research methods.

SETTING

Childbirth centres and NBS laboratories from six countries in East, West and Southern Africa.

PARTICIPANTS

Eight programme leaders involved with establishing and operating NBS programmes for SCD in Angola, Democratic Republic of Congo, Ghana, Liberia, Nigeria and Tanzania.

PRIMARY AND SECONDARY OUTCOME MEASURES

Data obtained through a structured, phased interview approach were analysed using a combination of inductive and deductive codes and used to determine primary themes related to the implementation and sustainability of SCD NBS programmes.

RESULTS

Four primary themes emerged from the analysis relating to governance (eg, pragmatic considerations when deploying overcommitted clinical staff to perform NBS), technical (eg, design and execution of operational processes), cultural (eg, variability of knowledge and perceptions of community-based staff) and financial (eg, issues that can arise when external funding may effectively preclude government inputs) aspects. Key learnings included perceived factors that contribute to long-term NBS programme sustainability.

CONCLUSIONS

The establishment of enduring NBS programmes is a proven approach to improving the health of populations with SCD. Organising such programmes in Africa is feasible, but initial implementation does not assure sustainability. Our analysis suggests that future programmes should prioritise government partner participation and funding from the earliest stages of programme development.

Optimal strategies for carrier screening and prenatal diagnosis of α- and β-thalassemia

The thalassemias are inherited quantitative disorders of hemoglobin synthesis with a significant worldwide burden, which result in a wide spectrum of disease from the most severe transfusion-dependent form to the mildest asymptomatic carrier state. In this article, we discuss the importance of carrier, prenatal, and newborn screening for thalassemia. We examine the rationale for who should be screened and when, as well as the current methodology for screening. Deficiencies in the newborn screening program are highlighted as well. With the advent of inexpensive and rapid genetic testing, this may be the most practical method of screening in the future, and we review the implications of population-based implementation of this strategy. Finally, a case-based overview of the approach for individuals with the trait as well as prospective parents who have a potential fetal risk of the disease is outlined.

Screening by Self-Report Underestimates Sickle Cell Trait in High-School Athletes

Background: Sickle cell trait (SCT) has received attention as a cause of death in college athletes, leading to mandatory lab SCT screening in National Collegiate Athletic Association (NCAA) athletes. High-school athletes are commonly screened by self-report. There are no known studies for evaluating whether this method is effective as a screening tool.

Hypothesis: The local prevalence rate of SCT as self-reported on the preparticipation evaluation (PPE) forms would be lower than the national accepted average.

Methods: PPE forms from the Department of Orthopedics and Rehabilitation of the University of Florida (UF) were reviewed between January 1, 2017, and April 30, 2018. The Florida High School PPE form includes a yes/no question to assess the diagnosis of SCT. The prevalence established by self-report was then compared with the national prevalence for SCT in the comparable race/ethnicity groups reported by the CDC. The response rate of SCT questions was also compared to other common cardiac screening questions.

Results: A total of 401 forms were reviewed. Six (1.5%) students answered “yes,” 351 answered “no,” and 44 left the SCT question blank. All six athletes who self-reported “yes” were Black and made up 3.7% of the 162 known Black respondents. This self-report rate for Black/African Americans was well below the expected 7.3% described by the CDC. Response rates were also lower than the comparable cardiac screening questions.

Conclusions: Self-report SCT status rates are lower than the accepted prevalence in a similar population. Significant inconsistencies in reporting were also determined.

Clinical relevance: This is a rare study to evaluate the self-reported prevalence of SCT in high-school athletes. Below average reporting of SCT and inconsistency in completion of the forms increase the concern for accuracy and effectiveness of current high-school SCT screening methods relying on self-report.

Challenging the dogma of the healthy heterozygote: Implications for newborn screening policies and practices

Heterozygous (carrier) status for an autosomal recessive condition is traditionally considered to lack significance for an individual's health, but this assumption has been challenged by a growing body of evidence. Carriers of several autosomal recessive disorders and some X-linked diseases are potentially at risk for the pathology manifest in homozygotes. This minireview provides an overview of the literature regarding health risks to carriers of two common autosomal recessive conditions on the Recommended Uniform Screening Panel: sickle cell disease [sickle cell trait (SCT)] and cystic fibrosis (CF). We also consider and comment on bioethical and policy implications for newborn blood screening (NBS). Health risks for heterozygotes, while relatively low for individuals, are often influenced by intrinsic (e.g., other genomic variants or co-morbidities) and extrinsic (environmental) factors, which present opportunities for personalized genomic medicine and risk counseling. They create a special challenge, however, for developing screening/follow-up policies and for genetic counseling, particularly after identification and reporting of heterozygote status through NBS. Although more research is needed, this minireview of the SCT and CF literature to date leads us to propose that blanket terms such as "healthy heterozygotes" or "unaffected carriers" should be superseded in communications about NBS results, in favor of a more nuanced paradigm of setting expectations for health outcomes with "genotype-to-risk." In the molecular era of NBS, it remains clear that public health needs to become better prepared for the full range of applied genetics.

Health services use by children identified as heterozygous hemoglobinopathy mutation carriers via newborn screening

Background

Newborn screening (NBS) for sickle cell disease incidentally identifies heterozygous carriers of hemoglobinopathy mutations. In Ontario, Canada, these carrier results are not routinely disclosed, presenting an opportunity to investigate the potential health implications of carrier status. We aimed to compare rates of health services use among children identified as carriers of hemoglobinopathy mutations and those who received negative NBS results.

Methods

Eligible children underwent NBS in Ontario from October 2006 to March 2010 and were identified as carriers or as screen-negative controls, matched to carriers 5:1 based on neighbourhood and timing of birth. We used health care administrative data to determine frequencies of inpatient hospitalizations, emergency department (ED) visits, and physician encounters through March 2012, using multivariable negative binomial regression to compare rates of service use in the two cohorts. We analyzed data from 4987 carriers and 24,935 controls.

Results

Adjusted incidence rate ratios (95% CI) for service use in carriers versus controls among children < 1 year of age were: 1.11 (1.06–1.17) for ED visits; 0.97 (0.89–1.06) for inpatient hospitalization; and 1.02 (1.00–1.04) for physician encounters. Among children ≥1 year of age, adjusted rate ratios were: 1.03 (0.98–1.07) for ED visits; 1.14 (1.03–1.25) for inpatient hospitalization and 0.92 (0.90–0.94) for physician encounters.

Conclusions

While we identified statistically significant differences in health services use among carriers of hemoglobinopathy mutations relative to controls, effect sizes were small and directions of association inconsistent across age groups and health service types. Our findings are consistent with the assumption that carrier status is likely benign in early childhood.

Successful Implementation of Newborn Screening for Hemoglobin Disorders in the Philippines

The Philippine newborn bloodspot screening (NBS) program began in 1996 with 24 hospitals and was formalized by legislation in 2004. The NBS panel was recently expanded to include a number of additional hereditary congenital conditions. Expertise and experiences from other NBS programs already screening for hemoglobinopathies were essential to its successful integration into the ongoing dried bloodspot NBS program in the Philippines. Building on clinical experiences and population data from Filipinos born in California, USA, hemoglobinopathies (including thalassemias) were selected for inclusion in the expanded screening panel. Hemoglobinopathy NBS, using high performance liquid chromatography, was implemented in a stepwise manner into the seven regional NBS screening laboratories. A central university laboratory provides confirmatory testing using both capillary electrophoresis and molecular methodologies. NBS results indicating carriers are followed up with educational fact sheets, while results of presumptive disease are referred for confirmatory testing and follow-up with a hematologist. Long-term care is provided through newborn screening continuity clinics across the country. Hemoglobinopathy NBS is now included in the national insurance package and screening uptake continues to increase nationally, exceeding 90% of all newborns in 7400+ hospitals and birthing centers nationwide prior to the COVID-19 pandemic.

Health beliefs as a predictor of screening behaviors among college students

Twenty million people live with a sickle cell disease (SCD) diagnosis globally; about 100,000 reside in the United States of America (US). Although SCD continues to threaten the health, mostly of particular groups in the US, there is a lack of knowledge on risk factors such as unawareness of carrier status, inheritance patterns, and resistance to SCT screening among childbearing age individuals. A cross-sectional survey design using a modified version of the Health Belief Survey assessed college students' SCD beliefs and screening behaviors. Four hundred sixteen students from a North Texas university campus participated in the survey. Although most participants believed that knowing their carrier status was important, only 26% were aware of their status. Findings demonstrated that health beliefs were a significant predictor of screening behaviors. The Universal, Selective, and Indicated Prevention Approach was suggested as a suitable approach to educate, transform health beliefs, and augment screening participation.

Pain-Related Injustice Appraisals in Youth with Sickle Cell Disease: A Preliminary Investigation

OBJECTIVES

Sickle cell disease (SCD) is a genetic disorder that affects approximately 100,000 Americans, the majority of whom are African American. SCD-related pain often has deleterious effects on functioning and quality of life. The inherited nature of SCD, SCD-related stigma, and serious physical and functional impact of SCD-related pain create a situation ripe for individuals to appraise their SCD-related pain as unfair or unjust. The aim of this preliminary investigation is to explore the extent to which pediatric patients with SCD appraise their pain as unjust and how these appraisals relate to functioning.

METHODS

Participants were youth with SCD (N = 30, mean age = 11.3, 57% boys) who attended a hematology clinic visit. Patients were invited to complete paper-based questionnaires assessing pain-related injustice appraisals, pain catastrophizing, pain and hurt, functional disability, depression, anxiety, and peer relationships.

RESULTS

Results of hierarchical regressions indicate that pain-related injustice significantly predicted functional disability, depression, and anxiety after controlling for patient pain and catastrophizing.

CONCLUSIONS

These findings suggest that pain-related injustice appraisals are an important contributor to the pain experience of youth with SCD. Early identification and remediation of pain-related injustice appraisals could have long-term functional benefits for youth with SCD.

The Use of Whole Genome and Exome Sequencing for Newborn Screening: Challenges and Opportunities for Population Health

Newborn screening (NBS) is a population-based program with a goal of reducing the burden of disease for conditions with significant clinical impact on neonates. Screening tests were originally developed and implemented one at a time, but newer methods have allowed the use of multiplex technologies to expand additions more rapidly to standard panels. Recent improvements in next-generation sequencing are also evolving rapidly from first focusing on individual genes, then panels, and finally all genes as encompassed by whole exome and genome sequencing. The intersection of these two technologies brings the revolutionary possibility of identifying all genetic disorders in newborns, allowing implementation of therapies at the optimum time regardless of symptoms. This article reviews the history of newborn screening and early studies examining the use of whole genome and exome sequencing as a screening tool. Lessons learned from these studies are discussed, along with technical, ethical, and societal challenges to broad implementation.

Improving the Capacity of Health System and Community for Sickle Cell Disease Screening and Management Among Tribal Population in India: Protocol of an Intervention Study

Sickle cell disease (SCD) is one of the major public health problems in the world. In India, the burden of SCD is comparatively high in socio-economically disadvantaged tribal communities. Though efficacious interventions are available to manage SCD, they are not reaching to these communities and no comprehensive programme is in place in the health care system. Therefore, the Indian Council of Medical Research has initiated a nation-wide study to develop an effective intervention model for SCD patients in tribal areas through the government health care system. This intervention includes increasing awareness and preparing the communities for accessing the government health care system for SCD care, and improving the capacity of the primary health care systems including the training of the health care providers on prevention and management of SCD. The study adopted a quasi-experimental design with pre-vs. post-intervention comparisons of outcome variables within the interventional groups and with the control group. The study will be implemented in 6 districts which are endemic for SCD, spread across different geographical zones of India. In each district, four primary health centre (PHC) areas which are predominantly inhabited by tribal population will be selected. Of these four PHC areas, two will be selected randomly for implementing the intervention and the remaining two will be the control area. Information necessary for development and implementation of the intervention will be gathered during formative research, by using both quantitative and qualitative research methods. Intervention with an inclusive partnership and community mobilization will be implemented. The major steps in the implementation of intervention are partnership building with various health and non-health partners including the community. Capacity building and strengthening is another important component to enable the primary health facilities to screen and manage SCD patients. Primarily, sub-health centres and primary healthcare centres will be equipped with appropriate SCD screening techniques. All doctors in the system will be trained in advanced treatment and management issues. To improve the community's awareness and readiness, community mobilization activities will be conducted. An impact evaluation will be carried out at the end of the intervention by comparing the improvement of SCD management in intervention PHCs to that of the control PHCs. However, the process evaluation and necessary mid-term corrections will be made throughout the intervention period. Thus, an intervention model in terms of its suitability, replicability and sustainability for the tribal population will be developed and tested. The findings of this study are more suitable to use during advocacy and to replicate the model by the state health departments. This study develops and places an appropriate referral system for SCD patients at the PHC level. Improving the community's access to health care, improving the quality of care in government health centres and raising awareness among tribal communities are crucial to achieving through innovation. Taken together, these innovations would significantly contribute to better access to health care and management of the SCD patients of underserved tribal population.

Bridging the Gap between Scientific Advancement and Real-World Application: Pediatric Genetic Counseling for Common Syndromes and Single-Gene Disorders

Screening and diagnostic testing for single-gene disorders and common syndromes in the pediatric setting frequently generate data that are challenging to interpret, and the ability to diagnose genetic conditions has outpaced the development of successful treatments or cures. Genetic testing is now integrated purposefully into a variety of primary and specialty care clinics, creating an increased requirement for genetic literacy among providers and patients, as well as a growing need to incorporate genetic counseling services into mainstream clinical practice. The practice of pediatric genetic counseling encompasses a unique combination of skills and training designed to address the evolving psychological, social, educational, medical, and reproductive concerns of patients and their families, which complements the multidisciplinary services of physicians, nurses, and other allied health professionals caring for patients with pediatric-onset genetic conditions. The potential range of genetic counseling needs in the pediatric setting transcends the diagnostic period. The sustained nature of pediatric care presents opportunities for development of trusting and longstanding professional relationships that permit the evolving genetic counseling needs of patients and families to be met. A discussion of cystic fibrosis, a common autosomal recessive single-gene disorder with an increasingly broad clinical spectrum and genotype-phenotype variability, serves as a useful case study to illustrate the current and emerging genetic counseling practices, goals, and challenges impacting patients and their families.

Perceptions and Practice of Early Diagnosis of Sickle Cell Disease by Parents and Physicians in a Southwestern State of Nigeria

Background

Early sickle cell disease (SCD) diagnosis has shown promise in combating SCD in many countries. The aim of this study was to assess the practice and perception of early SCD diagnosis among a group of parents and physicians in Nigeria. Patients and Methods. This was a cross-sectional descriptive study conducted to assess the opinions and practice of early diagnosis of SCD among 135 physicians caring for SCD patients and 164 mothers of children with SCD in a southwestern state of Nigeria.

Results

Most physicians 132 (97.8%) were aware of prenatal SCD diagnosis, but only 51 (37.8%) would recommend it. Most physicians 129 (95.6%) routinely recommend premarital SCD genetic counseling and testing, and 89 (65.1%) were aware of the national government newborn screening program but lesser proportion 75 (55.6%) were willing to recommend it. Amongst the mothers, 154 (94%) and 158 (96%) had encountered genetic counseling for SCD and were willing to offer newborn screening to their children, respectively. On the contrary, fewer mothers 42 (25%) were aware of prenatal SCD diagnosis, 28 (17%) were willing to partake in it, and 44 (26%) were undecided. There were discrepancies in the willingness by physicians to practice early SCD diagnosis and its uptake by mothers (p < 0.0001). The commonest reason given by both the physicians and mothers for not practicing SCD prenatal diagnosis was the high cost of the procedure.

Conclusion

The perceptions and practice of early SCD diagnosis was suboptimal in the study locality. Scaling up awareness and universal coverage are required.

Paper-based microchip electrophoresis for point-of-care hemoglobin testing

Nearly 7% of the world's population live with a hemoglobin variant. Hemoglobins S, C, and E are the most common and significant hemoglobin variants worldwide. Sickle cell disease, caused by hemoglobin S, is highly prevalent in sub-Saharan Africa and in tribal populations of Central India. Hemoglobin C is common in West Africa, and hemoglobin E is common in Southeast Asia. Screening for significant hemoglobin disorders is not currently feasible in many low-income countries with the high disease burden. Lack of early diagnosis leads to preventable high morbidity and mortality in children born with hemoglobin variants in low-resource settings. Here, we describe HemeChip, the first miniaturized, paper-based, microchip electrophoresis platform for identifying the most common hemoglobin variants easily and affordably at the point-of-care in low-resource settings. HemeChip test works with a drop of blood. HemeChip system guides the user step-by-step through the test procedure with animated on-screen instructions. Hemoglobin identification and quantification is automatically performed, and hemoglobin types and percentages are displayed in an easily understandable, objective way. We show the feasibility and high accuracy of HemeChip via testing 768 subjects by clinical sites in the United States, Central India, sub-Saharan Africa, and Southeast Asia. Validation studies include hemoglobin E testing in Bangkok, Thailand, and hemoglobin S testing in Chhattisgarh, India, and in Kano, Nigeria, where the sickle cell disease burden is the highest in the world. Tests were performed by local users, including healthcare workers and clinical laboratory personnel. Study design, methods, and results are presented according to the Standards for Reporting Diagnostic Accuracy (STARD). HemeChip correctly identified all subjects with hemoglobin S, C, and E variants with 100% sensitivity, and displayed an overall diagnostic accuracy of 98.4% in comparison to reference standard methods. HemeChip is a versatile, mass-producible microchip electrophoresis platform that addresses a major unmet need of decentralized hemoglobin analysis in resource-limited settings.

Comparison of US Federal and Foundation Funding of Research for Sickle Cell Disease and Cystic Fibrosis and Factors Associated With Research Productivity

IMPORTANCE

Sickle cell disease (SCD) and cystic fibrosis (CF) are severe autosomal recessive disorders associated with intermittent disease exacerbations that require hospitalizations, progressive chronic organ injury, and substantial premature mortality. Research funding is a limited resource and may contribute to health care disparities, especially for rare diseases that disproportionally affect economically disadvantaged groups.

OBJECTIVE

To compare disease-specific funding between SCD and CF and the association between funding and research productivity.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study examined federal and foundation funding, publications indexed in PubMed, clinical trials registered in ClinicalTrials.gov, and new drug approvals from January 1, 2008, to December 31, 2018, in an estimated US population of approximately 90 000 individuals with SCD and approximately 30 000 individuals with CF.

MAIN OUTCOMES AND MEASURES

Federal and foundation funding, publications indexed in PubMed, clinical trial registrations, and new drug approvals.

RESULTS

From 2008 through 2018, federal funding was greater per person with CF compared with SCD (mean [SD], $2807 [$175] vs $812 [$147]; P < .001). Foundation expenditures were greater for CF than for SCD (mean [SD], $7690 [$3974] vs $102 [$13.7]; P < .001). Significantly more research articles (mean [SD], 1594 [225] vs 926 [157]; P < .001) and US Food and Drug Administration drug approvals (4 vs 1) were found for CF compared with SCD, but the total number of clinical trials was similar (mean [SD], 27.3 [6.9] vs 23.8 [6.3]; P = .22).

CONCLUSIONS AND RELEVANCE

The findings show that disparities in funding between SCD and CF may be associated with decreased research productivity and novel drug development for SCD. Increased federal and foundation funding is needed for SCD and other diseases that disproportionately affect economically disadvantaged groups to address health care disparities.

Simple Test, Complex System: Multifaceted Views of Newborn Screening Science, Technology, and Policy

Newborn screening (NBS) is a public health service provided for all babies born in the United States and in most countries of the developed world. A series of tests are applied to the blood taken from newborn babies to detect genetic and metabolic disorders that can be treated if identified early. With early treatment and therapy, the affected babies can usually live a normal, healthy life. Timing for sampling, testing, and reporting is vital for NBS to function as an effective system. In order to be an effective system, the evolution of science, technology, and policy gradually had to come into a synchronous partnership, where the discovery of new genetic disorders led to timely development of technology for screening, which is supported by policy and implemented into practice. The timely "dance" of these partnerships in an era of personalized health and medicine forms the integrated approach supporting NBS. This review will include a brief history of scientific development, policymaking, and the economic consideration in the expansion of the NBS.

Inequities in newborn screening: Race and the role of medicaid☆

Newborn Screening (NBS) is a State-run program that mandates all newborns to be screened for a panel of medical conditions to reduce infant mortality and morbidity. Medicaid is a public health insurance program that expanded access to care for low-income infants. NBS mandates and Medicaid rolled out state-by-state in the 1960s, 70s, and 80s, which are considered significant programs that improved infant health in the latter half of the 20th Century. This article utilized variation in States' timing of NBS mandates and Medicaid implementation to examine changes in infant mortality rates among white and African American infants associated with NBS, Medicaid, and their interaction. The analyses used data from birth and death certificates in the US Vital Statistics from 1959 to 1995. We find that the implementation of NBS mandates alone was not associated with significant declines in infant mortality and coincided with increases in within-state racial inequities. States experienced mortality declines and reduction in racial inequities after implementing Medicaid with NBS mandates.

The current state of sickle cell trait: implications for reproductive and genetic counseling

Sickle cell trait (SCT) is unique among the carrier states that are identified during newborn screening. Unlike other heterozygous states for rare recessive diseases, SCT is exceedingly prevalent throughout regions of the world, making sickle cell disease one of the most common monogenetic diseases worldwide. Because of this high frequency, reproductive counseling is of paramount importance. In addition, unlike other carrier states, SCT seems to be a risk factor for several clinical complications, such as extreme exertional injury, chronic kidney disease, and venous thromboembolism. Increasing knowledge about these clinical outcomes can help inform genetic counseling recommendations. Expanding research and clinical efforts are needed to ensure that the promises of modern and precision medicine can be delivered to the millions of SCT carriers and their children.

Parental Attitudes Towards Prenatal Genetic Testing For Sickle Cell Disease

Uptake of prenatal genetic testing (PGT) is low among those with sickle cell disease (SCD). This study evaluated the association of knowledge and attitudes towards prenatal genetic counseling (PGC), awareness of posttesting intervention options and omission bias with attitudes towards PGT. In addition, we explored changes among knowledge, attitudes, and awareness of options following exposure to an educational, clinical vignette among parents of children with SCD. Parents (n=44) completed a questionnaire and an educational, clinical vignette presenting a detailed account of a pregnant woman with sickle cell trait seeking PGT and PGC was read to each participant. t Tests, Spearman correlations, multivariable regressions, and moderation/mediation analyses were used. More positive attitudes towards PGC (P=0.01), lesser tendency of omission bias (P<0.01) and private insurance (P=0.04) were significant correlates of more positive attitudes towards PGT. Omission bias mediated the relationship of attitudes towards PGC and attitudes towards PGT (95% confidence interval: 0.13, 3.03). Awareness of options (P=0.02), knowledge of PGC (P=0.01) and knowledge of PGT (P=0.01) significantly improved after exposure to the clinical vignette. Patients and families with SCD can benefit from education about the importance of prenatal diagnosis to improve attitudes, address omission bias and promote more informed decisions of PGT.

Assessing Knowledge of Sickle Cell Trait/Disease Inheritance in Metropolitan Detroit

Sickle cell disease (SCD) is an autosomal recessive disease not specific to one race. This study aims to assess knowledge about the inheritance pattern of sickle cell disease among college students in the Metropolitan Detroit area. An electronic survey was administered to undergraduate students at Oakland University, and first through fourth year medical students at Oakland University William Beaumont School of Medicine (OUWB). The primary analysis compared knowledge of sickle cell disease inheritance pattern between different demographic categories. A total of 146 Oakland University (27.4%) and OUWB (72.6%) students responded to the survey. The average age of the respondents was 24.27 ± 4.09. The majority of respondents were female (61%) and white (72.6%). In total, three (3) respondents - 1 white, 1 Asian and 1 African American, reported knowing that they have sickle cell disease/trait. In addition, one (1) white female respondent reported having an infant carrying the sickle cell trait. Most respondents (95.9%) knew that sickle cell disease/trait is genetically inherited, but a majority believed that it is associated only with African-Americans (67.8%). Respondents who were college graduates were more likely to correctly identify SCD inheritance patterns (98% compared to 85% of undergraduates; p = 0.002) and less likely to correctly answer the question "Who gets the disease?" (24% compared to 63%; p < 0.001). Most respondents (75%) think people should know if they have sickle cell trait/disease before marriage. The result shows that most respondents believe sickle cell disease is specific to African-Americans. However, because it is equally possible for all races to inherit this disease, knowing one's status could help prevent sickle cell-related deaths during rigorous exercises and enable individuals of reproductive age to make informed reproductive decisions in order to decrease sickle cell disease prevalence, and its associated financial and psychosocial burdens.

Hb Gibbon [β124(H2)Pro→Thr (HBB: c.373C>A, p.P125T)], an Asymptomatic Novel Hemoglobin Variant Detected by Newborn Screening

We describe here a previously unreported hemoglobin (Hb) variant, Hb Gibbon [β124(H2)Pro→Thr (HBB: c.373C>A, p.P125T)] detected by newborn Hb screening in a term male with no family history for hemoglobinopathy or other screening abnormalities. This missense mutation produces a β-globin chain variant that was detected by high performance liquid chromatography (HPLC) methods, but is silent by capillary electrophoresis (CE). DNA sequencing studies revealed that his father was also a heterozygote for this mutation. Neither has abnormalities on complete blood count (CBC) or any symptomatology.

CE: Understanding the Complications of Sickle Cell Disease

: Sickle cell disease (SCD) is an autosomal recessive genetic condition that alters the shape and function of the hemoglobin molecule in red blood cells. While the overall survival rate among children with SCD has improved in recent years, pediatric rates of hospitalization, ED use, and mortality from complications of SCD remain high. Among patients ages 18 and older, hospital admission and ED usage are even greater-and the median age at death of people with SCD is considerably lower than that of the general population. Nurses who care for patients with SCD have an opportunity to improve health outcomes and quality of life for these patients by recognizing the major SCD-associated complications and providing patients and their caregivers with appropriate educational information. The authors discuss the genetic, hematologic, and clinical features of SCD and describe the major associated health complications. In addition, they review the nursing implications of each complication and provide online links to resources for clinicians, patients, and caregivers.

Improving an Administrative Case Definition for Longitudinal Surveillance of Sickle Cell Disease

Objective:

Several states are building infrastructure and data collection methods for longitudinal, population-based surveillance systems for selected hemoglobinopathies. The objective of our study was to improve an administrative case definition for sickle cell disease (SCD) to aid in longitudinal surveillance.

Methods:

We collected data from 3 administrative data sets (2004-2008) on 1998 patients aged 0-21 in Georgia who had ≥1 encounter in which an SCD International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code was recorded, and we compared these data with data from a laboratory and medical record review. We assessed performance (sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV]) of case definitions that differed by number and type of SCD-coded encounters; addition of SCD-associated treatments, procedures, and complications; and length of surveillance (1 vs 5 years). We identified correct diagnoses for patients who were incorrectly coded as having SCD.

Results:

The SCD case definition of ≥3 SCD-coded encounters in 5 years simplified and substantially improved the sensitivity (96.0% vs 85.8%) and NPV (68.2% vs 38.2%) of the original administrative case definition developed for 5-year, state-based surveillance (≥2 encounters in 5 years and ≥1 encounter for an SCD-related treatment, procedure, or complication), while maintaining a similar PPV (97.4% vs 97.4%) and specificity (76.5% vs 79.0%).

Conclusions:

This study supports an administrative case definition that specifies ≥3 ICD-9-CM–coded encounters to identify SCD with a high degree of accuracy in pediatric patients. This case definition can be used to help establish longitudinal SCD surveillance systems.

Misdiagnosis: Acute Chest Syndrome That Evolved into Acute Respiratory Distress Syndrome in a Patient without a Documented History of Hemoglobinopathy

Acute chest syndrome (ACS) is a feared complication of sickle cell disease. Here is a case of a patient who presented with symptoms suggestive of acute chest syndrome yet had a delayed diagnosis presumably due to the lack of documented history of sickle cell disease of the patient, consequently evolving into acute respiratory distress syndrome (ARDS). He was subsequently diagnosed with heterozygous sickle cell SC disease on hemoglobin electrophoresis. After appropriate management with mechanical ventilator, broad-spectrum empiric intravenous antibiotics, exchange transfusion, and intravenous fluid resuscitation, the patient was medically optimized and safely discharged home, with significant improvement noted on successive follow-up visits.

Newborn Screening for SCD in the USA and Canada

Sickle cell disease (SCD) encompasses a group of inherited red cell disorders characterized by an abnormal hemoglobin, Hb S. The most common forms of SCD in the United States and Canada are identified through universal newborn screening (NBS) programs. Now carried out in all fifty U.S. states and 8 Canadian provinces, NBS for SCD represents one of the major public health advances in North America. The current status of NBS programs for hemoglobinopathies and the screening techniques employed in many regions worldwide reflect in large part the U.S. and Canadian experiences. Although the structure, screening algorithms and laboratory procedures, as well as reporting and follow up, vary between NBS programs, the overall workflow is similar. The current review summarized the historical background, current approaches, and methods used to screen newborns for SCD in the United States and Canada.

The current state of sickle cell trait: implications for reproductive and genetic counseling

Sickle cell trait (SCT) is unique among the carrier states that are identified during newborn screening. Unlike other heterozygous states for rare recessive diseases, SCT is exceedingly prevalent throughout regions of the world, making sickle cell disease one of the most common monogenetic diseases worldwide. Because of this high frequency, reproductive counseling is of paramount importance. In addition, unlike other carrier states, SCT seems to be a risk factor for several clinical complications, such as extreme exertional injury, chronic kidney disease, and venous thromboembolism. Increasing knowledge about these clinical outcomes can help inform genetic counseling recommendations. Expanding research and clinical efforts are needed to ensure that the promises of modern and precision medicine can be delivered to the millions of SCT carriers and their children.

Clinical Outcomes Associated With Sickle Cell Trait: A Systematic Review

Background

Although sickle cell trait (SCT) is largely a benign carrier state, it may increase risk for certain clinical outcomes.

Purpose

To evaluate associations between SCT and clinical outcomes in children and adults.

Data Sources

English-language searches of PubMed, CINAHL, the Cochrane Library, Current Contents Connect, Scopus, and Embase (1 January 1970 to 30 June 2018) and bibliographies of review articles.

Study Selection

Observational controlled studies (published in English) in children or adults that examined an association between SCT and any of 24 clinical outcomes specified a priori in the following 6 categories: exertion-related injury; renal, vascular, pediatric, and surgery- or trauma-related outcomes; and overall mortality.

Data Extraction

A single reviewer extracted study data, which was checked by another; 2 reviewers independently assessed study quality; and strength of evidence was assessed by consensus.

Data Synthesis

Of 7083 screened studies, 41 met inclusion criteria. High-strength evidence supported a positive association between SCT and risk for pulmonary embolism, proteinuria, and chronic kidney disease. Moderate-strength evidence supported a positive association between SCT and exertional rhabdomyolysis and a null association between SCT and deep venous thrombosis, heart failure or cardiomyopathy, stroke, and pediatric height or weight. Absolute risks for thromboembolism and rhabdomyolysis were small. For the remaining 15 clinical outcomes, data were insufficient or strength of evidence was low.

Limitation

Publication bias was possible, and high-quality evidence was scant.

Conclusion

Sickle cell trait is a risk factor for a few adverse health outcomes, such as pulmonary embolism, kidney disease, and exertional rhabdomyolysis, but does not seem to be associated with such complications as heart failure and stroke. Insufficient data or low-strength evidence exists for most speculated complications of SCT.

Primary Funding Source

National Human Genome Research Institute.

The Anticipatory Politics of Improving Childhood Survival for Sickle Cell Disease

Crediting scientific discovery for prolonging life is pervasive in biomedical histories of the genetic blood disorder, sickle cell disease. This includes the preventive strategies, such as newborn screening, that have underwritten the success of its life-extending interventions. Newborn screening is a technology that relies not only upon intact health infrastructures but also expertise and enhanced vigilance on the part of caregivers to anticipate complications while they are still open to circumvention. This paper posits that even after overcoming institutional barriers to make newborn screening equitably available, care and vigilance are resources that are themselves subject to what i term anticipatory politics, where structural conditions also stratify expectations for the future, including the affective appeal of medical innovations. This paper elaborates the paradigm of anticipatory politics through an ethnographic examination of newborn screening to connect the comprehensive care practices that have improved survival for sickle cell disease, and as the burden of mortality shifts to young adulthood, to expose how those who are resourced to care for these futures preferentially stand to benefit from preventive interventions.

Sickle Cell Clinical Research and Intervention Program (SCCRIP): A lifespan cohort study for sickle cell disease progression from the pediatric stage into adulthood

BACKGROUND

Previous natural history studies have advanced the understanding of sickle cell disease (SCD), but generally have not included sufficient lifespan data or investigation of the role of genetics in clinical outcomes, and have often occurred before the widespread use of disease-modifying therapies, such as hydroxyurea and chronic erythrocyte transfusions. To further advance knowledge of SCD, St. Jude Children's Research Hospital established the Sickle Cell Clinical Research and Intervention Program (SCCRIP), to conduct research in a clinically evaluated cohort of individuals with SCD across their lifetime.

PROCEDURES

Initiated in 2014, the SCCRIP study prospectively recruits patients diagnosed with SCD and includes retrospective and longitudinal collection of clinical, neurocognitive, geospatial, psychosocial, and health outcomes data. Biological samples are banked for future genomics and proteomics studies. The organizational structure of SCCRIP is based upon organ/system-specific working groups and is opened to the research community for partnerships.

RESULTS

As of August 2017, 1,044 (92.3% of eligible) patients with SCD have enrolled in the study (860 children and 184 adults), with 11,915 person-years of observation. Population demographics included mean age at last visit of 11.3 years (range 0.7-30.1), 49.8% females, 57.7% treated with hydroxyurea, 8.5% treated with monthly transfusions, and 62.9% hemoglobin (Hb) SS or HbSB⁰ -thalassemia, 25.7% HbSC, 8.4% HbsB⁺ -Thalassemia, 1.7% HbS/HPFH, and 1.2% other.

CONCLUSIONS

The SCCRIP cohort will provide a rich resource for the conduct of high impact multidisciplinary research in SCD.

Population Screening for Hemoglobinopathies

Hemoglobinopathies are the most common single-gene disorders in the world. Their prevalence is predicted to increase in the future, and low-income hemoglobinopathy-endemic regions need to manage most of the world's affected persons. International organizations, governments, and other stakeholders have initiated national or regional prevention programs in both endemic and nonendemic countries by performing population screening for α- and β-thalassemia, HbE disease, and sickle cell disease in neonates, adolescents, reproductive-age adults (preconceptionally or in the early antenatal period), and family members of diagnosed cases. The main aim of screening is to reduce the number of affected births and, in the case of sickle cell disease, reduce childhood morbidity and mortality. Screening strategies vary depending on the population group, but a few common screening test methods are universally used. We discuss the salient features of population-screening programs around the globe as well as current and proposed screening test methodologies.

Thalassemia in the laboratory: pearls, pitfalls, and promises

Thalassemia is one of the most common hereditary disorders of the developing world, and it is associated with severe anemia and transfusion dependence. The global health burden of thalassemia has increased as a result of human mobility and migration in recent years. Depending on inherited mutations, thalassemia patients exhibit distorted hemoglobin (Hb) patterns and deviated red cell indices, both of which can be used to support identification by diagnostic tools. Diagnostic approaches vary depending on the target population and the aim of the testing. Current methods, which are based on Hb patterns, are used for first-line screening, whereas molecular testing is needed for conformation of the results and for prenatal and preimplantation genetic diagnosis. In the present paper, we review the diagnostic parameters, pitfalls, interfering factors, and methods; currently available best-practice guidelines; quality assurance and standardization of the procedures; and promising laboratory technologies for the future of thalassemia diagnosis.

Sickle cell disease

Sickle cell disease (SCD) is a group of inherited disorders caused by mutations in HBB, which encodes haemoglobin subunit β. The incidence is estimated to be between 300,000 and 400,000 neonates globally each year, the majority in sub-Saharan Africa. Haemoglobin molecules that include mutant sickle β-globin subunits can polymerize; erythrocytes that contain mostly haemoglobin polymers assume a sickled form and are prone to haemolysis. Other pathophysiological mechanisms that contribute to the SCD phenotype are vaso-occlusion and activation of the immune system. SCD is characterized by a remarkable phenotypic complexity. Common acute complications are acute pain events, acute chest syndrome and stroke; chronic complications (including chronic kidney disease) can damage all organs. Hydroxycarbamide, blood transfusions and haematopoietic stem cell transplantation can reduce the severity of the disease. Early diagnosis is crucial to improve survival, and universal newborn screening programmes have been implemented in some countries but are challenging in low-income, high-burden settings.