Predictive genetic testing for adult-onset disorders in minors: a critical analysis of the arguments for and against the 2013 ACMG guidelines

Incidental finding at methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA): how to proceed?

Introduction: Since the advent of new generation sequencing, professionals are aware of the possibility of obtaining findings unrelated to the pathology under study. However, this possibility is usually forgotten in the case of studies aimed at a single gene or region. We report a case of a 16-month-old girl with clinical suspicion of Silver-Russell syndrome (SRS). Methods: Following the international SRS consensus, methylation alterations and copy number variations (CNVs) at 11p15 region and maternal uniparental disomy of chromosome 7 were analysed and discarded by MS-MLPA. Results: Unexpectedly, the 11p15 region MS-MLPA showed a decrease in the signal of a copy number reference probe. Deletions affecting a single probe are inconclusive. So, we faced the ethical dilemma of whether it was appropriate to confirm this alteration with independent techniques and to offer a diagnostic possibility that was in no way related to clinical suspicion. Fortunately, in this particular case, the informed consent had not been specific to a particular pathology but to any disorder associated with growth failure. Performed alternative studies allowed the final diagnosis of 22q deletion syndrome. Conclusion: We demonstrate the importance of informing patients about the possibility of obtaining incidental findings in genetic techniques (not only in next generation sequencing) during pre-test genetic counselling consultations. In addition, we highlight the relevance of including in the informed consent the option of knowing these unexpected incidental findings as in some cases, this will help to elucidate the definitive diagnosis and provide the correct follow-up and treatment.

Studying the impact of translational genomic research: Lessons from eMERGE

Two major goals of the Electronic Medical Record and Genomics (eMERGE) Network are to learn how best to return research results to patient/participants and the clinicians who care for them and also to assess the impact of placing these results in clinical care. Yet since its inception, the Network has confronted a host of challenges in achieving these goals, many of which had ethical, legal, or social implications (ELSIs) that required consideration. Here, we share impediments we encountered in recruiting participants, returning results, and assessing their impact, all of which affected our ability to achieve the goals of eMERGE, as well as the steps we took to attempt to address these obstacles. We divide the domains in which we experienced challenges into four broad categories: (1) study design, including recruitment of more diverse groups; (2) consent; (3) returning results to participants and their health care providers (HCPs); and (4) assessment of follow-up care of participants and measuring the impact of research on participants and their families. Since most phases of eMERGE have included children as well as adults, we also address the particular ELSI posed by including pediatric populations in this research. We make specific suggestions for improving translational genomic research to ensure that future projects can effectively return results and assess their impact on patient/participants and providers if the goals of genomic-informed medicine are to be achieved.

Outlining the Clinical Profile of TCIRG1 14 Variants including 5 Novels with Overview of ARO Phenotype and Ethnic Impact in 20 Egyptian Families

TCIRG1 gene mutations underlie osteopetrosis, a rare genetic disorder impacting osteoclast function with consequent brittle bones prone to fracture, in spite of being characterized by increased bone density. The disorder is known to exhibit marked genetic heterogeneity, has no treatment, and is lethal in most instances. There are reports of ethnic variations affecting bone mineral density and variants' expression as diverse phenotypes even within individuals descending from the same pedigree. We herein focus on one of osteopetrosis's three types: the autosomal recessive malignant form (MIM 259700) (ARO) that is almost always associated with severe clinical symptoms. We reviewed the results of about 1800 Egyptian exomes and we did not detect similar variants within our Egyptian dataset and secondary neurological deficit. We studied twenty Egyptian families: sixteen ARO patients, ten carrier parents with at least one ARO affected sib, and two fetuses. They were all subjected to thorough evaluation and TCIRG1 gene sequencing. Our results of twenty-eight individuals descending from twenty Egyptian pedigrees with at least one ARO patient, expand the phenotype as well as genotype spectrum of recessive mutations in the TCIRG1 gene by five novel pathogenic variants. Identifying TCIRG1 gene mutations in Egyptian patients with ARO allowed the provision of proper genetic counseling, carrier detection, and prenatal diagnosis starting with two families included herein. It also could pave the way to modern genomic therapeutic approaches.

Evaluating a general pediatric/adult genetic counseling clinic in a Midwest medical center

In 2018, the Munroe-Meyer Institute for Genetics & Rehabilitation (MMI) at the University of Nebraska Medical Center (UNMC) in Omaha, NE created a genetic counseling clinic (GCC) to increase access to genetics services and decrease the time spent between a referral and being seen in a general genetics outpatient clinic. In the GCC, genetic counselors led patient encounters and geneticists served as advisors, rather than primary providers. We conducted a chart review of 109 patients seen in the GCC from November 1, 2018, to March 16, 2020, and obtained information regarding patient demographics, indications, and clinical recommendations as a result of the visit. Most patients seen in this clinic were female (65.1%) and aged 19 years of age or older (54.1%). The primary indications for patients in this clinic included review genetic test results (42.2%), coordination of genetic testing for a known familial variant (30.2%), and concerns for personal or family history suspicious of a genetic condition without dysmorphic features (24.8%). The average patient wait time between referral date and appointment date in the GCC was 49.8 days. The two most common clinical recommendations made by genetic counselors in the GCC were genetic testing (56.1%) and/or follow-up with specialist (26.5%). These specialists primarily included endocrinology (n = 5), neurology (n = 4), cardiology (n = 4), ophthalmology (n = 3), and audiology (n = 3). We found that the GCC model may be appropriate for patients with (1) genetic test results requiring interpretation, (2) a known familial variant or (3) genetic testing recommended by a specialist physician. Descriptions of the indications and recommendations for patients seen in this GCC provide a framework for potential implementation of a GCC in other regions across the nation.

The Evolving Role of Next Generation Sequencing in Pediatric Neurosurgery: a Call for Action for Research, Clinical Practice, and Optimization of Care

NGS (Next-Generation Sequencing) is one of the most promising technologies that have truly revolutionized many aspects of clinical practice in recent years. It has been and is increasingly applied in many disciplines of medicine; however, it appears that pediatric neurosurgery despite its great potential has not truly embraced this new technology and is hesitant to employ it in its routine practice and guidelines. In this review, we briefly summarized the developments that lead to the establishment of NGS technology, reviewed the current applications and potentials of NGS in the disorders treated by pediatric neurosurgeons, and lastly discuss the steps we need to take to better harness NGS in pediatric neurosurgery.

Managing Pandora's Box: Familial Expectations around the Return of (Future) Germline Results

BACKGROUND

Pediatric oncology patients are increasingly being offered germline testing to diagnose underlying cancer predispositions. Meanwhile, as understanding of variant pathogenicity evolves, planned reanalysis of genomic results has been suggested. Little is known regarding the types of genomic information that parents and their adolescent children with cancer prefer to receive at the time of testing or their expectations around the future return of genomic results.

METHODS

Parents and adolescent children with cancer eligible for genomic testing for cancer predisposition were surveyed regarding their attitudes and expectations for receiving current and future germline results (ClinicalTrials.gov Identifier: NCT02530658).

RESULTS

All parents (100%) desired to learn about results for treatable or preventable conditions, with 92.4% wanting results even when there is no treatment or prevention. Parents expressed less interest in receiving uncertain results for themselves (88.3%) than for their children (95.3%). Most parents (95.9%) and adolescents (87.9%) believed that providers have a responsibility to share new or updated germline results indefinitely or at any point during follow-up care. Fewer parents (67.5%) indicated that they would want results if their child was deceased: 10.3% would not want to be contacted, 19.3% were uncertain.

CONCLUSIONS

Expectations for return of new or updated genomic results are high among pediatric oncology families, although up to one third of parents have reservations about receiving such information in the event of their child's death. These results underscore the importance of high-quality pre-and post-test counseling, conducted by individuals trained in consenting around genomic testing to elicit family preferences and align expectations around the return of germline results.

“Spazio Huntington”: Tracing the Early Motor, Cognitive and Behavioral Profiles of Kids with Proven Pediatric Huntington Disease and Expanded Mutations > 80 CAG Repeats

The “Spazio Huntington—A Place for Children” program was launched in 2019. The aim was to contact at risk kids within Huntington disease (HD) families, to provide counseling to their parents and to start a prospective follow-up of kids suspicious to manifest pediatric HD (PHD). We met 25 at risk kids in two years, four of whom with PHD and highly expanded (HE) mutations beyond 80 CAG repeats. We rated motor, neuropsychological and behavioral changes in all PHD kids by the Unified HD Rating Scale (UHDRS)-total motor score (TMS) and additional measures of (1) cognitive level (Leiter International Performance Scale), (2) adaptive functioning (Adaptive Behavior Assessment Systems), (3) receptive language (Peabody Picture Vocabulary Test) and (4) behavioral abnormalities (Child Behavior Check List and Children’s Yale–Brown Obsessive Compulsive Scale). All PHD kids showed a severe progression of neurological and psychiatric manifestations including motor, cognitive and behavioral changes. The magnetic resonance imaging contributed to confirm the suspicious clinical observation by highlighting very initial striatum abnormalities in PHD. Spazio Huntington is a program to prospectively study PHD, the most atypical face of HD, and may represent the basis to recruit PHD patients in future clinical trials.

A practical approach to the genomics of kidney disorders

Rapid technological advances in genomic testing continue to increase our understanding of the genetic basis of a wide range of kidney disorders. Establishing a molecular diagnosis benefits the individual by bringing an end to what is often a protracted diagnostic odyssey, facilitates accurate reproductive counselling for families and, in the future, is likely to lead to the delivery of more targeted management and surveillance regimens. The selection of the most appropriate testing modality requires an understanding both of the technologies available and of the genetic architecture and heterogeneity of kidney disease. Whilst we are witnessing a far greater diagnostic yield with broader genetic testing, such approaches invariably generate variants of uncertain significance and secondary incidental findings, which are not only difficult to interpret but present ethical challenges with reporting and feeding back to patients and their families. Here, we review the spectrum of nephrogenetic disorders, consider the optimal approach to genetic testing, explore the clinical utility of obtaining a molecular diagnosis, reflect on the challenges of variant interpretation and look to the future of this dynamic field.

The full spectrum of ethical issues in pediatric genome-wide sequencing: a systematic qualitative review

Background

The use of genome-wide sequencing in pediatric medicine and research is growing exponentially. While this has many potential benefits, the normative and empirical literature has highlighted various ethical issues. There have not been, however, any systematic reviews of these issues. The aim of this systematic review is to determine systematically the spectrum of ethical issues that is raised for stakeholders in in pediatric genome-wide sequencing.

Methods

A systematic review in PubMed and Google Books (publications in English or German between 2004 and 2021) was conducted. Further references were identified via reference screening. Data were analyzed and synthesized using qualitative content analysis. Ethical issues were defined as arising when a relevant normative principle is not adequately considered or when two principles come into conflict.

Results

Our literature search retrieved 3175 publications of which 143 were included in the analysis. Together these mentioned 106 ethical issues in pediatric genome-wide sequencing, categorized into five themes along the pediatric genome-wide sequencing lifecycle. Most ethical issues identified in relation to genome-wide sequencing typically reflect ethical issues that arise in general genetic testing, but they are often amplified by the increased quantity of data obtained, and associated uncertainties. The most frequently discussed ethical aspects concern the issue of unsolicited findings.

Conclusion

Concentration of the debate on unsolicited findings risks overlooking other ethical challenges. An overarching difficulty presents the terminological confusion: both with regard to both the test procedure/ the scope of analysis, as well as with the topic of unsolicited findings. It is important that the genetics and ethics communities together with other medical professions involved work jointly on specific case related guidelines to grant the maximum benefit for the care of the children, while preventing patient harm and disproportionate overload of clinicians and the healthcare system by the wealth of available options and economic incentives to increase testing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02830-w.

Please give me a copy of my child's raw genomic data

In this work, we explore whether raw genetic data generated during sequencing ought to be returned to a pediatric patient and/or their parents/guardians. We identify the principles used by various professional societies in their guidelines on the return of secondary findings and apply them to this new context. We conclude that since each situation is unique, decisions should be made on a case-by-case basis according to the best interests of the child.

A Novel Triplet-Primed PCR Assay to Detect the Full Range of Trinucleotide CAG Repeats in the Huntingtin Gene (HTT)

The expanded CAG repeat number in HTT gene causes Huntington disease (HD), which is a severe, dominant neurodegenerative illness. The accurate determination of the expanded allele size is crucial to confirm the genetic status in symptomatic and presymptomatic at-risk subjects and avoid genetic polymorphism-related false-negative diagnoses. Precise CAG repeat number determination is critical to discriminate the cutoff between unexpanded and intermediate mutable alleles (IAs, 27–35 CAG) as well as between IAs and pathological, low-penetrance alleles (i.e., 36–39 CAG repeats), and it is also critical to detect large repeat expansions causing pediatric HD variants. We analyzed the HTT-CAG repeat number of 14 DNA reference materials and of a DNA collection of 43 additional samples carrying unexpanded, IAs, low and complete penetrance alleles, including large (>60 repeats) and very large (>100 repeats) expansions using a novel triplet-primed PCR-based assay, the AmplideX PCR/CE HTT Kit. The results demonstrate that the method accurately genotypes both normal and expanded HTT-CAG repeat numbers and reveals previously undisclosed and very large CAG expansions >200 repeats. We also show that this technique can improve genetic test reliability and accuracy by detecting CAG expansions in samples with sequence variations within or adjacent to the repeat tract that cause allele drop-outs or inaccuracies using other PCR methods.

Exercise and arrhythmic risk in TMEM43 p.S358L arrhythmogenic right ventricular cardiomyopathy

BACKGROUND

High-level exercise has been associated with a malignant phenotype in desmosomal and genotype-negative forms of arrhythmogenic right ventricular cardiomyopathy (ARVC). This is the first study to examine this issue with ARVC secondary to the TMEM43 p.S358L mutation.

OBJECTIVE

The purpose of this study was to evaluate the impact of exercise on arrhythmic risk and cardiac death in TMEM43 p.S358L ARVC.

METHODS

Individuals with the TMEM43 p.S358L mutation enrolled in a prospective registry who had received a primary prevention implantable cardioverter-defibrillator (ICD) were invited to complete the modified Paffenbarger Physical Activity Questionnaire to assess their physical activity in the year before their ICD implantation. Time-to-event analyses using unadjusted and adjusted Cox proportional hazards models evaluated associations between physical activity and first appropriate ICD discharge secondary to malignant ventricular arrhythmia or cardiac death.

RESULTS

In 80 subjects with the TMEM43 p.S358L mutation, exercise ≥9.0 metabolic equivalent of task (MET)-hours/day (high level) in the year before ICD implantation was associated with an adjusted 9.1-fold increased hazard of first appropriate ICD discharge (there were no deaths) relative to physical activity <9.0 MET-hours/day (moderate level) (95% confidence interval [CI] 3.3-24.6 MET-hours/day; P < .001). The median age from birth to first appropriate ICD discharge was 58.5 years (95% CI 56.5-60.5 years) vs 35.8 years (95% CI 28.2-43.4 years) (P < .001) in subjects in moderate- and high-level exercise groups, respectively.

CONCLUSION

Exercise ≥9.0 MET-hours/day is associated with an increased risk of malignant ventricular arrhythmias in the TMEM43 p.S358L subtype of ARVC. Extrapolating these data, we suggest molecular testing be offered in early childhood to inform exercise choices reflective of the genotype.

Predictive Testing for Tumor Predisposition Syndromes in Pediatric Relatives: An Asian Experience

Approximately 10% of pediatric cancer patients possess germline pathogenic/likely pathogenic variants (PV/LPV) in known tumor predisposition genes. Predictive testing is the optimal approach to identify asymptomatic at-risk relatives to guide gene-directed surveillance for early cancer detection and/or risk-reducing strategies. However, the uptake rate for predictive testing remains low in Asian countries. We aim to evaluate the uptake rate of predictive testing in a pediatric population (aged under 21-years-old) in a multi-ethnic Asian cancer center. Our retrospective analysis included families with PV/LPVs identified in genes associated with pediatric tumor predisposition. Of the 83 pediatric first-degree relatives (FDRs) from 49 unrelated families, 20 FDRs (24.1%) originating from 13 families (26.6%) underwent predictive testing. Genes tested in pediatric FDRs were APC, RB1, SBDS, SDHA, SDHB, SDHD, and TP53. All pediatric FDRs of probands with PV/LPVs in RB1 and biallelic PVs in SBDS underwent predictive testing, while <45% of pediatric FDRs had predictive testing for familial PV/LPVs identified in the APC, SDHA, SDHB, SDHD, and TP53 genes. Amongst the 13 families who underwent pre-test counseling, 80% of pediatric FDRs in these families proceeded with predictive testing. Malay pediatric FDRs and siblings of probands were more likely to undergo predictive testing. We conclude that the predictive testing rate in pediatric FDRs is higher than that of adult FDRs in Asia, but still below the global average. We postulate factors that may influence predictive testing uptake in pediatric FDRs includes a lack of genetics awareness, concerns regarding insurance, and genetic discrimination.

Rethinking the "open future" argument against predictive genetic testing of children

Professional consensus has traditionally discouraged predictive genetic testing when no childhood interventions can reduce future morbidity or mortality. However, advances in genome sequencing and accumulating evidence that children and families cope adequately with predictive genetic information have weakened this consensus. The primary argument remaining against testing appeals to children's "right to an open future." It claims that the autonomy of the future adult is violated when others make an irreversible choice to obtain or disclose predictive genetic information during childhood. We evaluate this argument and conclude that children's interest in an open future should not be understood as a right. Rather an open future is one significant interest to weigh against other important interests when evaluating decisions. Thus, predictive genetic testing is ethically permissible in principle, as long as the interests promoted outweigh potential harms. We conclude by offering an expanded model of children's interests that might be considered in such circumstances, and present two case analyses to illustrate how this framework better guides decisions about predictive genetic testing in pediatrics.

Genetic Counseling in Huntington's Disease: Potential New Challenges on Horizon?

Huntington's disease (HD) is a rare, hereditary, neurodegenerative and dominantly transmitted disorder affecting about 10 out of 100,000 people in Western Countries. The genetic cause is a CAG repeat expansion in the huntingtin gene (HTT), which is unstable and may further increase its length in subsequent generations, so called anticipation. Mutation repeat length coupled with other gene modifiers and environmental factors contribute to the age at onset in the offspring. Considering the unpredictability of age at onset and of clinical prognosis in HD, the accurate interpretation, a proper psychological support and a scientifically sound and compassionate communication of the genetic test result are crucial in the context of Good Clinical Practice and when considering further potential disease-modifying therapies. We discuss various genetic test scenarios that require a particularly careful attention in psychological and genetic counseling and expect that the counseling procedures will require a constant update.

"A change in perspective": Exploring the experiences of adolescents with hereditary tumor predisposition

BACKGROUND

Hereditary tumor predisposition syndromes (HTPSs) are being recognized more frequently in the etiology of pediatric cancer. Previous research indicates that disclosure of tumor susceptibility is a significant event in adolescents' lives. Insight into adolescents' adjustment to knowledge of their syndromes can guide healthcare delivery, particularly genetic counseling. This study explored the experiences of adolescents with hereditary tumor predisposition and their perceptions of living at risk.

METHODS

Seven adolescents, ages 14 to 17, representing six different childhood-onset HTPSs, were purposively sampled and interviewed using a study-specific semistructured interview guide. We explored the disclosure process, support systems, and the perceived benefits and harms of knowledge of hereditary tumor susceptibility. Interview transcripts were analyzed via interpretive description.

RESULTS

Three major themes emerged from the data: (1) The benefits of knowledge outweigh the harms; (2) context surrounding genetic testing must be recognized; and (3) self-concept is influenced but not defined by tumor risk.

CONCLUSIONS

We conclude that adolescents recognize the challenges associated with awareness of tumor predisposition but may also identify positive aspects in their experiences, reflecting a changed life perspective. Results of this exploratory study suggest strategies that can guide pretest and posttest genetic counseling of adolescents for HTPSs, facilitating the adaptive incorporation of genetic information into an adolescent's self-concept.

Views from the clinic: Healthcare provider perspectives on whole genome sequencing in paediatrics

Whole genome sequencing (WGS) is a transformative technology which promises improved diagnostic rates compared to conventional genetic testing strategies and tailored approaches to patient care. Due to the practical and ethical complexities associated with using WGS, particularly in the paediatric context, input from a broad spectrum of healthcare providers can guide implementation strategies. We recruited healthcare providers from the largest paediatric academic health science centre in Canada and conducted semi-structured qualitative interviews, exploring experiences with and perceptions of the opportunities and challenges associated with WGS. Interview transcripts were coded and analyzed thematically. Interviews were completed with 14 genetics professionals (geneticists and genetic counsellors) and 15 non-genetics professionals (physician sub-specialists and nurses). Genetics professionals ordered genetic tests more often and reported greater confidence on pre- and post-test genetic counselling compared to non-genetics professionals. Most healthcare providers endorsed WGS when a more specific test was either not available or not likely to yield a diagnosis. While genetics professionals raised concerns regarding the time demands associated with reviewing WGS variants, non-genetics professionals reflected concerns about knowledge and training. Providers' position on reporting secondary variants to parents drew upon but was not limited to the concept of best interests. Taken together, understanding practical and principled matters of WGS from healthcare providers' perspectives can guide ongoing efforts to implement WGS in paediatrics.

Parental attitudes and expectations towards receiving genomic test results in healthy children

Little evidence is available to guide returning genomic results in children without medical indication for sequencing. Professional guidelines for returning information on adult-onset conditions are conflicting. The goal of this study was to provide preliminary information on parental attitudes and expectations about returning medically actionable genomic results in children who have been sequenced as part of a population biobank.Four focus groups of parents with a child enrolled in a population biobank were conducted. A deliberative engagement format included education about professional guidelines and ethical issues around returning results to children. Parents were presented two scenarios where their healthy child has a pathogenic variant for: (a) a medically actionable childhood condition; (b) a hereditary cancer syndrome with no medical management until adulthood. Thematic analysis was conducted on verbatim transcripts. Regardless of the scenario, parents stated that the genomic information was important, was like other unexpected medical information, and disclosure should be tailored to the child's age and result. Parents wanted the results in their child's medical record. Reasons for learning adult-onset results in their healthy children included to prepare their child for necessary medical action in adulthood. Parents also provided suggestions for program design. This preliminary evidence suggests that parents desire genomic results and expect to use this information to protect their child's health. More empirical research on psychosocial adjustment to such information with continued engagement of parents and children is needed to further inform how to best support families in the communication and use of genomic information.

Genetic Testing: Ethical Aspects

The aim of this article is to provide an analysis of the main issues related to the application of predictive medicine by analysing the most significant ethical implications. Genetic medicine is indeed a multidisciplinary matter that covers broad contexts, sometimes transversely. Its extreme complexity, coupled with possible perceived repercussions on an individual's life, involves important issues in the ethical, deontological and legal medical field. The aspects related to the execution of genetic testing have to be addressed at different levels, starting with the correct information about the "cognitive" meaning they intend (by forcefully disassociating it from the strange "preventive aspect") to the legal medical issues that can be aroused in the field of forensic pathology, medical responsibility and insurance. There is no doubt that in recent years, from the decoding of the human genome, genetic research has exponentially expanded with an equally exponential increase in its use in clinical practice and the ethical and social evolution of it.

Genome-wide sequencing technologies: A primer for paediatricians

Genetic testing has been a routine part of paediatic medicine for decades. Over time, the number of genetic tests available for children presenting with features thought to be explained by an underlying genetic aetiology has expanded considerably. Genome-wide sequencing approaches (e.g., whole-exome sequencing, whole-genome sequencing) are now emerging as the most comprehensive approaches to genetic diagnosis that we have seen to date; multiple serial tests that were once required for a child under diagnostic investigation can now be accomplished in a single assay. Moreover, the performance of this single assay appears to be superior to the sum of its parts. Despite this promise, technical, ethical and access-related complexities require considerable attention prior to the implementation of these tools in mainstream paediatrics. To ready paediatricians for the eventual transition to genome-based diagnostics, herein we review both the elements and delivery considerations of this emerging technology.

Towards precision nephrology: the opportunities and challenges of genomic medicine

The expansion of genomic medicine is furthering our understanding of many human diseases. This is well illustrated in the field of nephrology, through the characterization, discovery, and growing insight into various renal diseases through use of Next Generation Sequencing (NGS) technologies. This review will provide an overview of the diagnostic opportunities of using genetic testing in the clinical setting by describing notable discoveries regarding inherited forms of renal disease that have advanced the field and by highlighting some of the potential benefits of establishing a molecular diagnosis in a clinical practice. In addition, it will discuss some of the challenges associated with the expansion of genetic testing into the clinical setting, including clinical variant interpretation and return of genetic results.

Review of Clinical Next-Generation Sequencing

CONTEXT

- Next-generation sequencing (NGS) is a technology being used by many laboratories to test for inherited disorders and tumor mutations. This technology is new for many practicing pathologists, who may not be familiar with the uses, methodology, and limitations of NGS.

OBJECTIVE

- To familiarize pathologists with several aspects of NGS, including current and expanding uses; methodology including wet bench aspects, bioinformatics, and interpretation; validation and proficiency; limitations; and issues related to the integration of NGS data into patient care.

DATA SOURCES

- The review is based on peer-reviewed literature and personal experience using NGS in a clinical setting at a major academic center.

CONCLUSIONS

- The clinical applications of NGS will increase as the technology, bioinformatics, and resources evolve to address the limitations and improve quality of results. The challenge for clinical laboratories is to ensure testing is clinically relevant, cost-effective, and can be integrated into clinical care.

Parents perspectives on whole genome sequencing for their children: qualified enthusiasm?

OBJECTIVE

To better understand the consequences of returning whole genome sequencing (WGS) results in paediatrics and facilitate its evidence-based clinical implementation, we studied parents' experiences with WGS and their preferences for the return of adult-onset secondary variants (SVs)-medically actionable genomic variants unrelated to their child's current medical condition that predict adult-onset disease.

METHODS

We conducted qualitative interviews with parents whose children were undergoing WGS as part of the SickKids Genome Clinic, a research project that studies the impact of clinical WGS on patients, families, and the healthcare system. Interviews probed parents' experience with and motivation for WGS as well as their preferences related to SVs. Interviews were analysed thematically.

RESULTS

Of 83 invited, 23 parents from 18 families participated. These parents supported WGS as a diagnostic test, perceiving clear intrinsic and instrumental value. However, many parents were ambivalent about receiving SVs, conveying a sense of self-imposed obligation to take on the 'weight' of knowing their child's SVs, however unpleasant. Some parents chose to learn about adult-onset SVs for their child but not for themselves.

CONCLUSIONS

Despite general enthusiasm for WGS as a diagnostic test, many parents felt a duty to learn adult-onset SVs. Analogous to 'inflicted insight', we call this phenomenon 'inflicted ought'. Importantly, not all parents of children undergoing WGS view the best interests of their child in relational terms, thereby challenging an underlying justification for current ACMG guidelines for reporting incidental secondary findings from whole exome and WGS.

Ethical considerations surrounding germline next-generation sequencing of children with cancer

INTRODUCTION

The advent of next-generation sequencing (NGS) has introduced an exciting new era in biomedical research. NGS forms the foundation of current genetic testing approaches, including targeted gene panel testing, as well as more comprehensive whole-exome and whole-genome sequencing. Together, these approaches promise to provide critical insights into the understanding of health and disease. However, with NGS testing come many ethical questions and concerns, particularly when testing involves children. These concerns are especially relevant for children with cancer, where the testing of tumor and germline tissues is increasingly being incorporated into clinical care. Areas covered: In this manuscript, we explore the key ethical considerations related to conducting germline NGS testing in pediatric oncology, focusing on the four main principles of beneficence, non-maleficence, autonomy and justice. Expert commentary: The ethical issues surrounding germline NGS testing are complex and result in part from our limited understanding of the medical relevance of many of the results obtained and poor knowledge of the impacts of testing, both beneficial and detrimental, on patients and their families. In this article we discuss the risks and benefits of germline NGS testing and the arguments for and against such testing in children with cancer.

Disease Resistance and the Definition of Genetic Enhancement

Recent gene editing experiments carried out in human embryos have raised the question of whether interventions like the introduction of a CCR5-Δ32 deletion, which could provide heritable resistance to HIV infection, ought to be considered enhancements. Many authors have used the term "enhancement" in different ways, some based on patients' biomedical outcomes and others on their social context. These classifications are often considered overly imprecise. Nevertheless, the concept of "enhancement" could affect the ways in which these applications are regulated in different jurisdictions, the availability of coverage by insurers or public health care, and the force of public opinion in shaping future policy on gene editing. In order to ethically situate resistance to communicable disease with reference to other techniques, this article provides an overview of its similarities and differences with disease gene therapy in embryos, gene therapy in consenting adults, and vaccination. In discussing key ethical features of CCR5-Δ32 deletion (including its frequency in various populations, biological mechanism, benefits for individuals, and use in previous clinical trials) we offer some potential guideposts for the continuing discussion on how to classify "enhancements" in the age of CRISPR gene editing.

Preferences for the provision of whole genome sequencing services among young adults

Objectives

As whole genome sequencing (WGS) becomes increasingly available, clinicians will be faced with conveying complex information to individuals at different stages in life. The purpose of this study is to characterize the views of young adults toward obtaining WGS, learning different types of genomic information, and having choice about which results are disclosed.

Methods

A mixed-methods descriptive study was conducted with a diverse group of 18 and 19-years-olds (N = 145). Participants watched an informational video about WGS and then completed an online survey.

Results

Participants held a positive attitude toward obtaining WGS and learning about a range of health conditions and traits. Increased interest in learning WGS information was significantly associated with anticipated capacity to handle the emotional consequences if a serious risk was found (β = 0.13, P = .04). Young adults wanted the ability to choose what types of genomic risk information would be returned and expressed decreased willingness to undergo WGS if clinicians made these decisions (t(138) = -7.14, P <.01). Qualitative analysis showed that young adults emphasized procedural factors in WGS decision-making and that perceived health benefits of WGS had a substantial role in testing preferences and anticipated usage of WGS results.

Conclusions

Clinicians are likely to encounter enthusiasm for obtaining WGS results among young adults and may need to develop strategies for ensuring that this preference is adequately informed.

Predictive Genetic Testing of Children for Adult-Onset Conditions: Negotiating Requests with Parents

Healthcare professionals (HCPs) regularly face requests from parents for predictive genetic testing of children for adult-onset conditions. Little is known about how HCPs handle these test requests, given that guidelines recommend such testing is deferred to adulthood unless there is medical benefit to testing before that time. Our study explored the process of decision-making between HCPs and parents. Semi-structured interviews were conducted with 34 HCPs in 8 regional genetic services across the UK, and data were thematically analysed. We found that instead of saying ‘yes’ or ‘no’ to such requests, many HCPs framed the consultation as an opportunity to negotiate the optimal time of testing. This, they argued, facilitates parents’ considered decision-making, since parents’ eventual decisions after requesting a test was often to defer testing their child. In cases where parents’ requests remained a sustained wish, most HCPs said they would agree to test, concluding that not testing would not serve the child’s wider best interest. As a strategy for determining the child’s best interest and for facilitating shared decision-making, we recommend that HCPs re-frame requests for testing from parents as a discussion about the optimal time of testing for adult-onset disease.

Young adults' attitudes toward pediatric whole-genome sequencing

AIM

To characterize the views of young adults toward integrating whole-genome sequencing (WGS) into standard pediatric care, particularly when used as a supplement to newborn screening.

MATERIALS & METHODS

This mixed methods descriptive study assessed the perspectives of a diverse group of 18- and 19-year olds (n = 145) in the USA using an informational video and online survey.

RESULTS

Young adults typically recommended disclosing WGS results to both parents and children during childhood. In the qualitative analysis, most participants emphasized the anticipated health benefits of pediatric WGS, while a minority discussed possible negative emotional and developmental impacts.

CONCLUSION

Differing preferences for pediatric WGS emphasize the importance that clinicians adopt responsive approaches when providing WGS and disclosing results to families.

Towards a European consensus for reporting incidental findings during clinical NGS testing

In 2013, the American College of Medical Genetics (ACMG) examined the issue of incidental findings in whole exome and whole genome sequencing, and introduced recommendations to search for, evaluate and report medically actionable variants in a set of 56 genes. At a debate held during the 2014 European Society for Human Genetics Conference (ESHG) in Milan, Italy, the first author of that paper presented this view in a debate session that did not end with a conclusive vote from the mainly European audience for or against reporting back actionable incidental findings. In this meeting report, we elaborate on the discussions held during a special meeting hosted at the ESHG in 2013 from posing the question 'How to reach a (European) consensus on reporting incidental findings and unclassified variants in diagnostic next generation sequencing'. We ask whether an European consensus exists on the reporting of incidental findings in genome diagnostics, and present a series of key issues that require discussion at both a national and European level in order to develop recommendations for handling incidental findings and unclassified variants in line with the legal and cultural particularities of individual European member states.

Incidental Findings with Genomic Testing: Implications for Genetic Counseling Practice

This paper summarizes the current controversies surrounding the identification and disclosure of "incidental" or "secondary" findings from genomic sequencing and the implications for genetic counseling practice. The rapid expansion of clinical sequencing has influenced the ascertainment and return of incidental findings, while empiric data to inform best practices are still being generated. Using the North Carolina Clinical Genomic Evaluation by Next Generation Exome Sequencing (NCGENES) research project as an example, we discuss the implications of different models of consent and their impact on patient decisions.

Genome-Wide Sequencing for Prenatal Detection of Fetal Single-Gene Disorders

New sequencing methods capable of rapidly analyzing the genome at increasing resolution have transformed diagnosis of single-gene or oligogenic genetic disorders in pediatric and adult medicine. Targeted tests, consisting of disease-focused multigene panels and diagnostic exome sequencing to interrogate the sequence of the coding regions of nearly all genes, are now clinically offered when there is suspicion for an undiagnosed genetic disorder or cancer in children and adults. Implementation of diagnostic exome and genome sequencing tests on invasively and noninvasively obtained fetal DNA samples for prenatal genetic diagnosis is also being explored. We predict that they will become more widely integrated into prenatal care in the near future. Providers must prepare for the practical, ethical, and societal dilemmas that accompany the capacity to generate and analyze large amounts of genetic information about the fetus during pregnancy.

The SickKids Genome Clinic: developing and evaluating a pediatric model for individualized genomic medicine

Our increasing knowledge of how genomic variants affect human health and the falling costs of whole-genome sequencing are driving the development of individualized genomic medicine. This new clinical paradigm uses knowledge of an individual's genomic variants to anticipate, diagnose and manage disease. While individualized genetic medicine offers the promise of transformative change in health care, it forces us to reconsider existing ethical, scientific and clinical paradigms. The potential benefits of pre-symptomatic identification of at-risk individuals, improved diagnostics, individualized therapy, accurate prognosis and avoidance of adverse drug reactions coexist with the potential risks of uninterpretable results, psychological harm, outmoded counseling models and increased health care costs. Here we review the challenges, opportunities and limits of integrating genomic analysis into pediatric clinical practice and describe a model for implementing individualized genomic medicine. Our multidisciplinary team of bioinformaticians, health economists, health services and policy researchers, ethicists, geneticists, genetic counselors and clinicians has designed a 'Genome Clinic' research project that addresses multiple challenges in pediatric genomic medicine--ranging from development of bioinformatics tools for the clinical assessment of genomic variants and the discovery of disease genes to health policy inquiries, assessment of clinical care models, patient preference and the ethics of consent.