Newborn screening: the genomic challenge

Genomic Newborn Screening for Pediatric Cancer Predisposition Syndromes: A Holistic Approach

As next-generation sequencing (NGS) has become more widely used, germline and rare genetic variations responsible for inherited illnesses, including cancer predisposition syndromes (CPSs) that account for up to 10% of childhood malignancies, have been found. The CPSs are a group of germline genetic disorders that have been identified as risk factors for pediatric cancer development. Excluding a few "classic" CPSs, there is no agreement regarding when and how to conduct germline genetic diagnostic studies in children with cancer due to the constant evolution of knowledge in NGS technologies. Various clinical screening tools have been suggested to aid in the identification of individuals who are at greater risk, using diverse strategies and with varied outcomes. We present here an overview of the primary clinical and molecular characteristics of various CPSs and summarize the existing clinical genomics data on the prevalence of CPSs in pediatric cancer patients. Additionally, we discuss several ethical issues, challenges, limitations, cost-effectiveness, and integration of genomic newborn screening for CPSs into a healthcare system. Furthermore, we assess the effectiveness of commonly utilized decision-support tools in identifying patients who may benefit from genetic counseling and/or direct genetic testing. This investigation highlights a tailored and systematic approach utilizing medical newborn screening tools such as the genome sequencing of high-risk newborns for CPSs, which could be a practical and cost-effective strategy in pediatric cancer care.

Using an experiment among clinical experts to determine the cost and clinical impact of rapid whole exome sequencing in acute pediatric settings

Objective

Evaluate the cost and clinical impacts of rapid whole-exome sequencing (rWES) for managing pediatric patients with unknown etiologies of critical illnesses through an expert elicitation experiment.

Method

Physicians in the intervention group (n = 10) could order rWES to complete three real-world case studies, while physicians in the control group (n = 8) could not. Costs and health outcomes between and within groups were compared.

Results

The cost incurred in the intervention group was consistently higher than the control by 60,000-70,000 THB. Fewer other investigation costs were incurred when rWES could provide a diagnosis. Less cost was incurred when an rWES that could lead to a change in management was ordered earlier. Diagnostic accuracy and the quality of non-pharmaceutical interventions were superior when rWES was available.

Conclusion

In acute pediatric settings, rWES offered clinical benefits at the average cost of 60,000-70,000 THB. Whether this test is cost-effective warrants further investigations. Several challenges, including cost and ethical concerns for assessing high-cost technology for rare diseases in resource-limited settings, were potentially overcome by our study design using expert elicitation methods.

Expanding the Australian Newborn Blood Spot Screening Program using genomic sequencing: do we want it and are we ready?

Since the introduction of genome sequencing in medicine, the factors involved in deciding how to integrate this technology into population screening programs such as Newborn Screening (NBS) have been widely debated. In Australia, participation in NBS is not mandatory, but over 99.9% of parents elect to uptake this screening. Gauging stakeholder attitudes towards potential changes to NBS is vital in maintaining this high participation rate. The current study aimed to determine the knowledge and attitudes of Australian parents and health professionals to the incorporation of genomic sequencing into NBS programs. Participants were surveyed online in 2016 using surveys adapted from previous studies. The majority of parents (90%) self-reported some knowledge of NBS, with 77% expressing an interest in NBS using the new technology. This was significantly lower than those who would utilise NBS using current technologies (99%). Although, many health professionals (62%) felt that new technologies should currently not be used as an adjunct to NBS, 79% foresaw the use of genomic sequencing in NBS by 2026. However, for genomic sequencing to be considered, practical and technical challenges as well as parent information needs were identified including the need for accurate interpretation of data; pre-and post-test counselling; and appropriate parental consent and opt-out process. Therefore, although some support for implementing genomic sequencing into Australian NBS does exist, there is a need for further investigation into the ethical, social, legal and practical implications of introducing this new technology as a replacement to current NBS methods.

Next-Generation Sequencing in Newborn Screening: A Review of Current State

Newborn screening was first introduced at the beginning of the 1960s with the successful implementation of the first phenylketonuria screening programs. Early expansion of the included disorders was slow because each additional disorder screened required a separate test. Subsequently, the technological advancements of biochemical methodology enabled the scaling-up of newborn screening, most notably with the implementation of tandem mass spectrometry. In recent years, we have witnessed a remarkable progression of high-throughput sequencing technologies, which has resulted in a continuous decrease of both cost and time required for genetic analysis. This has enabled more widespread use of the massive multiparallel sequencing. Genomic sequencing is now frequently used in clinical applications, and its implementation in newborn screening has been intensively advocated. The expansion of newborn screening has raised many clinical, ethical, legal, psychological, sociological, and technological concerns over time. This review provides an overview of the current state of next-generation sequencing regarding newborn screening including current recommendations and potential challenges for the use of such technologies in newborn screening.

Ethical and Psychosocial Implications of Genomic Newborn Screening

The potential for genomic screening of the newborn, specifically adding genomic screening to current newborn screening (NBS), raises very significant ethical issues. Regardless of whether NBS of this type would include entire genomes or only the coding region of the genome (exome screening) or even sequencing specific genes, the ethical issues raised would be enormous. These issues include the limitations of bioinformatic interpretation of identified variants in terms of pathogenicity and accurate prognosis, the potential for substantial uncertainty about appropriate diagnosis, therapy, and follow-up, the possibility of much anxiety among providers and parents, the potential for unnecessary treatment and "medicalizing" normal children, the possibility of adding large medical costs for otherwise unnecessary follow-up and testing, the potential for negatively impacting medical and life insurance, and the almost impossible task of obtaining truly-informed consent. Moreover, the potentially-negative consequences of adding genomic sequencing to NBS might jeopardize all of NBS which has been and continues to be so beneficial for thousands of children and their families throughout the world.

Next generation sequencing as a follow-up test in an expanded newborn screening programme

OBJECTIVES

Contrary to many western European countries, most south-eastern European countries do not have an expanded newborn screening (NBS) program using tandem mass spectrometry. This study would represent one of the first expanded NBS studies in south-eastern Europe and will enable the estimation of the incidences of IEM in Slovenia. We proposed an expanded NBS approach including next-generation sequencing (NGS) as a confirmational analysis.

DESIGN & METHODS

We conducted a pilot study of expanded NBS for selected inborn errors of metabolism (IEM) in Slovenia including 10,048 NBS cards. We used an approach including tandem mass spectrometry followed by second tier tests including NGS. Based on the NBS results, 85 children were evaluated at a metabolic follow-up; 80 of them were analyzed using NGS.

RESULTS

Altogether, glutaric acidemia type 1 was confirmed in one patient who was a compound heterozygote for two known causative GCDH variants. A patient with suspected very long-chain acyl-CoA dehydrogenase deficiency had negative metabolic follow-up tests, but had two heterozygous ACADVL variants; one known disease-causing variant and one indel, namely c.205-8_205-7delinsGC, that is predicted to be causative. Nine participants had elevated metabolites characteristic of 3-methylcrotonyl-CoA carboxylase deficiency, 2 of them had known causative homozygous variants in MCCC1. The other seven were heterozygous; two had a novel genetic variant c.149_151dupCCA (p.Thr50dup). Cumulative incidences of IEM in Slovenia were similar to other European countries.

CONCLUSIONS

NGS proved to be valuable in explaining the abnormal metabolite concentrations in NBS as it enabled the differentiation between affected patients and mere heterozygotes, and it improved the turnaround time of genetic analysis. The results of this study will be instrumental in the routine implementation of expanded NBS in Slovenia.

Long-term outcome of expanded newborn screening at Boston children's hospital: benefits and challenges in defining true disease

INTRODUCTION

There is no universal consensus of the disorders included in newborn screening programs. Few studies so far, mostly short-term, have compared the outcome of disorders detected by expanded newborn screening (ENBS) to the outcome of the same disorders detected clinically.

METHODS

We compared the clinical and neurodevelopmental outcomes in patients with metabolic disorders detected by ENBS, including biotinidase testing, with those detected clinically and followed at the Metabolism Clinic at Boston Children's Hospital.

RESULTS

One hundred eighty-nine patients came to attention from ENBS and 142 were clinically diagnosed. 3-methylcrotonyl-CoA carboxylase, biotinidase, and carnitine deficiencies were exclusively identified by ENBS and medium chain acyl-CoA dehydrogenase (MCADD) and very long chain acyl-CoA dehydrogenase deficiencies (VLCADD) were predominantly identified by ENBS whereas the organic acid disorders more often came to attention clinically. Only 2% of the ENBS-detected cases had clinically severe outcomes compared to 42% of those clinically detected. The mean IQ score was 103 + 17 for the ENBS-detected cases and 77 + 24 for those clinically detected. Those newly included disorders that seem to derive the greatest benefit from ENBS include the fatty acid oxidation disorders, profound biotinidase deficiency, tyrosinemia type 1, and perhaps carnitine deficiency.

CONCLUSION

Although the NBS-identified and clinically-identified cohorts were not completely comparable, this long-term study shows likely substantial improvement overall in the outcome of these metabolic disorders in the NBS infants. Infants with mild disorders and benign variants may represent a significant number of infants identified by ENBS. The future challenge will be to unequivocally differentiate the disorders most benefitting from ENBS and adjust programs accordingly.

Genomic newborn screening: public health policy considerations and recommendations

BACKGROUND

The use of genome-wide (whole genome or exome) sequencing for population-based newborn screening presents an opportunity to detect and treat or prevent many more serious early-onset health conditions than is possible today.

METHODS

The Paediatric Task Team of the Global Alliance for Genomics and Health's Regulatory and Ethics Working Group reviewed current understanding and concerns regarding the use of genomic technologies for population-based newborn screening and developed, by consensus, eight recommendations for clinicians, clinical laboratory scientists, and policy makers.

RESULTS

Before genome-wide sequencing can be implemented in newborn screening programs, its clinical utility and cost-effectiveness must be demonstrated, and the ability to distinguish disease-causing and benign variants of all genes screened must be established. In addition, each jurisdiction needs to resolve ethical and policy issues regarding the disclosure of incidental or secondary findings to families and ownership, appropriate storage and sharing of genomic data.

CONCLUSION

The best interests of children should be the basis for all decisions regarding the implementation of genomic newborn screening.

Newborn Screening for Lysosomal Storage Disorders

Newborn screening is one of the most important public health initiatives to date, focusing on the identification of presymptomatic newborn infants with treatable conditions to reduce morbidity and mortality. The number of screening conditions continues to expand due to advances in screening technologies and the development of novel therapies. Consequently, some of the lysosomal storage disorders are now considered as candidates for newborn screening, although many challenges including identification of late-onset phenotypes remain. This review provides a critical appraisal of the current state of newborn screening for lysosomal storage disorders.

Parental Views on Expanded Newborn Screening Using Whole-Genome Sequencing

BACKGROUND AND OBJECTIVE

The potential application of whole-genome sequencing (WGS) to state-mandated standard newborn screening (NBS) challenges the traditional public health approach to NBS and raises ethical, policy, and clinical practice issues. This article examines the perspectives and values of diverse healthy pregnant women and parents of children diagnosed with a primary immunodeficiency disorder about traditional NBS and expanded NBS with the use of WGS.

METHODS

We conducted 4 focus groups (3 in English and 1 in Spanish) with socioeconomically and ethnically diverse pregnant women (n = 26), and a comparison group with parents of children diagnosed with a primary immunodeficiency disorder (n = 5).

RESULTS

Pediatric policy-relevant themes that emerged from our analysis of the focus group data are presented within 4 categories: (1) perspectives on traditional NBS, (2) informed consent, (3) return of results, and (4) storage and retrieval of results. Analyses indicate that study participants desired greater inclusion in the NBS process. Despite an optimistic orientation to the potential benefits and limited harms likely to result from genomic applications of NBS, parents voiced concerns about privacy and control over test results. Limited trust in the medical system and the state-run NBS program informed these concerns.

CONCLUSIONS

Expanded NBS with WGS for pediatricians may require management of more genetic conditions, including mutations that convey risk to both the child and parents for adult-onset disorders, and an informed-consent process to manage the genomic data and storage of blood spots. Attention to how these technologies are understood in diverse populations is needed for effective implementation.

Psychosocial Factors Influencing Parental Interest in Genomic Sequencing of Newborns

BACKGROUND

When parents of newborns are presented with the hypothetical possibility of obtaining genomic sequencing (GS) for their newborn infants immediately after birth, they express substantial interest. This study examined associations between expressed interest in GS and demographic and psychosocial variables some months after birth.

METHODS

A total of 1096 parents were enrolled in a study on GS of newborns shortly after the birth of their infants, before discharge from the postpartum floor. Of these parents, 663 (60.5%) completed a follow-up survey 2 to 28 months later that queried their interest in GS for their infant and whether they received worrisome health information during pregnancy, labor, and delivery. They were also administered the Parenting Stress Index. Multivariate logistic regression was used to examine factors associated with interest in GS of newborns.

RESULTS

Of parents, 76.1% indicated at least some interest in GS. A 10-point increase on the Parenting Stress Index was associated with an increase in the odds of having some interest in GS (odds ratio: 1.15; 95% confidence interval: 1.01-1.32). Age, gender, race, ethnicity, marital status, education, anxiety, and whether this was the first biological child were not significantly associated with interest in GS. Receiving worrisome health information was associated with greater interest in GS but this did not reach significance (odds ratio: 1.42; 95% confidence interval: 0.95-2.12).

CONCLUSIONS

This hypothetical survey study suggests that previous experiences leading to worrisome health information and parenting stress need to be considered when GS is offered. Additional research, currently underway, is exploring factors associated with real-life parental choices around whether to obtain GS of their newborns.

Parents' experiences 12 years after newborn screening for genetic susceptibility to type 1 diabetes and their attitudes to whole-genome sequencing in newborns

PURPOSE

The potential for utilizing whole-genome sequencing in newborn screening (NBS) has been recognized, but the ethical, legal, and social issues of this may require further analysis. This article begins to address the gap in the literature concerning psychosocial effects of "genomic NBS," focusing on later effects of screening for genetic susceptibility to a single, complex disorder: type 1 diabetes (T1D). It also examines parental attitudes toward potential future expansions of NBS.

METHODS

Fifteen semistructured interviews were conducted with parents of children who had been tested for genetic susceptibility to T1D 12 years previously.

RESULTS

Parents in this study were not psychologically burdened by knowledge of their child's genetic risk but perceived little benefit. Most of these parents disclosed the result to their child at age 12 years without obvious adverse impact. Parents were unenthusiastic about potential future expansions of NBS to include similar genomic tests.

CONCLUSIONS

Absence of adverse psychosocial effects and ease of disclosure to the child represent initial positive findings, but they require replication and further evaluation in relation to uptake of prevention strategies. Attitudes of parents to "genomic NBS" are variable, suggesting that parental choice will be an important component of future screening programs.

Parents are interested in newborn genomic testing during the early postpartum period

PURPOSE

We surveyed parents to ascertain interest in newborn genomic testing and determine whether these queries would provoke refusal of conventional state-mandated newborn screening.

METHODS

After a brief genetics orientation, parents rated their interest in receiving genomic testing for their healthy newborn on a 5-point Likert scale and answered questions about demographics and health history. We used logistic regression to explore factors associated with interest in genomic testing and tracked any subsequent rejection of newborn screening.

RESULTS

We queried 514 parents within 48 hours after birth while still in hospital (mean age (SD) 32.7 (6.4) years, 65.2% female, 61.2% white, 79.3% married). Parents reported being not at all (6.4%), a little (10.9%), somewhat (36.6%), very (28.0%), or extremely (18.1%) interested in genomic testing for their newborns. None refused state-mandated newborn screening. Married participants and those with health concerns about their infant were less interested in newborn genomic testing (P = 0.012 and P = 0.030, respectively). Degree of interest for mothers and fathers was discordant (at least two categories different) for 24.4% of couples.

CONCLUSION

Interest in newborn genomic testing was high among parents of healthy newborns, and the majority of couples had similar levels of interest. Surveying parents about genomic sequencing did not prompt rejection of newborn screening.Genet Med 17 6, 501-504.

Genetics professionals' opinions of whole-genome sequencing in the newborn period

Newborn screening (NBS) programs have been successful in identifying infants with rare, treatable, congenital conditions. While current programs rely largely on biochemical analysis, some predict that in the future, genome sequencing may be used as an adjunct. The purpose of this exploratory pilot study was to begin to characterize genetics professionals' opinions of the use of whole-genome sequencing (WGS) in NBS. We surveyed members of the American College of Medical Genetics and Genomics (ACMG) via an electronic survey distributed through email. The survey included questions about results disclosure, the current NBS paradigm, and the current criteria for adding a condition to the screening panel. The response rate was 7.3 % (n = 113/1549). The majority of respondents (85 %, n = 96/113) felt that WGS should not be currently used in NBS, and that if it were used, it should not be mandatory (86.5 %, n = 96/111). However, 75.7 % (n = 84/111) foresee it as a future use of WGS. Respondents felt that accurate interpretation of results (86.5 %, n = 83/96), a more extensive consent process (72.6 %, n = 69/95), pre- (79.2 %, n = 76/96) and post-test (91.6 %, n = 87/95) counseling, and comparable costs (70.8 %, n = 68/96) and turn-around-times (64.6 %, n = 62/96) to current NBS would be important for using WGS in NBS. Participants were in favor of disclosing most types of results at some point in the lifetime. However, the majority (87.3 %, n = 96/110) also indicated that parents should be able to choose what results are disclosed. Overall, respondents foresee NBS as a future use of WGS, but indicated that WGS should not occur within the framework of traditional NBS. They agreed with the current criteria for including a condition on the recommended uniform screening panel (RUSP). Further discussion about these criteria is needed in order to better understand how they could be utilized if WGS is incorporated into NBS.