Screening Human Embryos for Polygenic Traits Has Limited Utility

Predicting the direction of phenotypic difference

Predicting phenotypes from genomic data is a key goal in genetics, but for most complex phenotypes, predictions are hampered by incomplete genotype-to-phenotype mapping. Here, we describe a more attainable approach than quantitative predictions, which is aimed at qualitatively predicting phenotypic differences. Despite incomplete genotype-to-phenotype mapping, we show that it is relatively easy to determine which of two individuals has a greater phenotypic value. This question is central in many scenarios, e.g., comparing disease risk between individuals, the yield of crop strains, or the anatomy of extinct vs extant species. To evaluate prediction accuracy, i.e., the probability that the individual with the greater predicted phenotype indeed has a greater phenotypic value, we developed an estimator of the ratio between known and unknown effects on the phenotype. We evaluated prediction accuracy using human data from tens of thousands of individuals from either the same family or the same population, as well as data from different species. We found that, in many cases, even when only a small fraction of the loci affecting a phenotype is known, the individual with the greater phenotypic value can be identified with over 90% accuracy. Our approach also circumvents some of the limitations in transferring genetic association results across populations. Overall, we introduce an approach that enables accurate predictions of key information on phenotypes - the direction of phenotypic difference - and suggest that more phenotypic information can be extracted from genomic data than previously appreciated.

Screening embryos for polygenic disease risk: a review of epidemiological, clinical, and ethical considerations

BACKGROUND

The genetic composition of embryos generated by in vitro fertilization (IVF) can be examined with preimplantation genetic testing (PGT). Until recently, PGT was limited to detecting single-gene, high-risk pathogenic variants, large structural variants, and aneuploidy. Recent advances have made genome-wide genotyping of IVF embryos feasible and affordable, raising the possibility of screening embryos for their risk of polygenic diseases such as breast cancer, hypertension, diabetes, or schizophrenia. Despite a heated debate around this new technology, called polygenic embryo screening (PES; also PGT-P), it is already available to IVF patients in some countries. Several articles have studied epidemiological, clinical, and ethical perspectives on PES; however, a comprehensive, principled review of this emerging field is missing.

OBJECTIVE AND RATIONALE

This review has four main goals. First, given the interdisciplinary nature of PES studies, we aim to provide a self-contained educational background about PES to reproductive specialists interested in the subject. Second, we provide a comprehensive and critical review of arguments for and against the introduction of PES, crystallizing and prioritizing the key issues. We also cover the attitudes of IVF patients, clinicians, and the public towards PES. Third, we distinguish between possible future groups of PES patients, highlighting the benefits and harms pertaining to each group. Finally, our review, which is supported by ESHRE, is intended to aid healthcare professionals and policymakers in decision-making regarding whether to introduce PES in the clinic, and if so, how, and to whom.

SEARCH METHODS

We searched for PubMed-indexed articles published between 1/1/2003 and 1/3/2024 using the terms 'polygenic embryo screening', 'polygenic preimplantation', and 'PGT-P'. We limited the review to primary research papers in English whose main focus was PES for medical conditions. We also included papers that did not appear in the search but were deemed relevant.

OUTCOMES

The main theoretical benefit of PES is a reduction in lifetime polygenic disease risk for children born after screening. The magnitude of the risk reduction has been predicted based on statistical modelling, simulations, and sibling pair analyses. Results based on all methods suggest that under the best-case scenario, large relative risk reductions are possible for one or more diseases. However, as these models abstract several practical limitations, the realized benefits may be smaller, particularly due to a limited number of embryos and unclear future accuracy of the risk estimates. PES may negatively impact patients and their future children, as well as society. The main personal harms are an unindicated IVF treatment, a possible reduction in IVF success rates, and patient confusion, incomplete counselling, and choice overload. The main possible societal harms include discarded embryos, an increasing demand for 'designer babies', overemphasis of the genetic determinants of disease, unequal access, and lower utility in people of non-European ancestries. Benefits and harms will vary across the main potential patient groups, comprising patients already requiring IVF, fertile people with a history of a severe polygenic disease, and fertile healthy people. In the United States, the attitudes of IVF patients and the public towards PES seem positive, while healthcare professionals are cautious, sceptical about clinical utility, and concerned about patient counselling.

WIDER IMPLICATIONS

The theoretical potential of PES to reduce risk across multiple polygenic diseases requires further research into its benefits and harms. Given the large number of practical limitations and possible harms, particularly unnecessary IVF treatments and discarded viable embryos, PES should be offered only within a research context before further clarity is achieved regarding its balance of benefits and harms. The gap in attitudes between healthcare professionals and the public needs to be narrowed by expanding public and patient education and providing resources for informative and unbiased genetic counselling.

Regulatory safeguards needed if preimplantation genetic testing for polygenic risk scores (PGT-P) is permitted in Singapore

Singapore, a highly affluent island city-state located in Southeast Asia, has increasingly leveraged new assisted reproductive technologies (ART) to overcome its dismal fertility rates in recent years. A new frontier in ART is preimplantation genetic testing (PGT) for polygenic risk scores (PRS) to predict complex multifactorial traits in IVF (in vitro fertilisation) embryos, such as type 2 diabetes, cardiovascular diseases and various other characteristics like height, intelligence quotient (IQ), hair and eye colour. Unlike well-known safety risks with human genome editing, there are negligible risks with PGT-P, because there are no man-made genetic modifications that can be transmitted to future generations. Nevertheless, the current efficacy of using PGT-P to select IVF embryos for either increased or decreased probability of developing specific polygenic traits is still far from certain. Hence, the regulatory safeguards proposed here will be based on the assumption that the efficacy of this new technology platform has already been validated. These include: (1) restricting the application of PGT-P only for prevention of clinically relevant polygenic disease traits, (2) securely blocking patients' access to the raw genomic DNA sequencing data of their IVF embryos, (3) validating diagnosis of polygenic disease traits in the prospective parents/grandparents of IVF embryos, and restricting PGT-P only for preventing specifically diagnosed polygenic disease traits and (4) mandating rigorous and comprehensive genetic counselling for IVF patients considering PGT-P. There is an urgent and dire need to prevent abuse of the PGT-P technique, as well as protect the interests and welfare of patients if its clinical application is to be permitted in the country.

Ready for polygenic risk scores? An analysis of regulation of preimplantation genetic testing in European countries

STUDY QUESTION

Would the different regulatory approaches for preimplantation genetic testing (PGT) in Europe permit the implementation of preimplantation genetic testing using polygenic risk scores (PGT-P)?

SUMMARY ANSWER

While the regulatory approaches for PGT differ between countries, the space provided for potential implementation of PGT-P seems limited in all three regulatory models.

WHAT IS KNOWN ALREADY

PGT is a reproductive genetic technology that allows the testing for hereditary genetic disorders and chromosome abnormalities in embryos before implantation. Throughout its history, PGT has largely been regarded as an ethically sensitive technology. For example, ethical questions have been raised regarding the use of PGT for adult-onset conditions, non-medical sex selection, and human leukocyte antigen typing for the benefit of existing siblings. Countries in which PGT is offered each have their own approach of regulating the clinical application of PGT, and a clear overview of legal and practical regulation of PGT in Europe is lacking. An emerging development within the field of PGT, namely PGT-P, is currently bringing new ethical tensions to the forefront. It is unclear whether PGT-P may be applied within the current regulatory frameworks in Europe. Therefore, it is important to investigate current regulatory frameworks in Europe and determine whether PGT-P fits within these frameworks.

STUDY DESIGN, SIZE, DURATION

The aim of this study was to provide an overview of the legal and practical regulation of the use of PGT in seven selected European countries (Belgium, France, Germany, Italy, the Netherlands, Spain, and the UK) and critically analyse the different approaches with regards to regulatory possibilities for PGT-P. Between July and September 2023, we performed a thorough and extensive search of websites of governments and governmental agencies, websites of scientific and professional organizations, and academic articles in which laws and regulations are described.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We investigated the legal and regulatory aspects of PGT by analysing legal documents, regulatory frameworks, scientific articles, and guidelines from scientific organizations and regulatory bodies to gather relevant information about each included country. The main sources of information were national laws relating to PGT.

MAIN RESULTS AND THE ROLE OF CHANCE

We divided the PGT regulation approaches into three models. The regulation of PGT differs per country, with some countries requiring central approval of PGT for each new indication (the medical indication model: the UK, the Netherlands), other countries evaluating each individual PGT request at the local level (the individual requests model: France, Germany), and countries largely leaving decision-making about clinical application of PGT to healthcare professionals (the clinical assessment model: Belgium, Italy, Spain). In the countries surveyed that use the medical indication model and the individual requests model, current legal frameworks and PGT criteria seem to exclude PGT-P. In countries using the clinical assessment model, the fact that healthcare professionals and scientific organizations in Europe are generally negative about implementation of PGT-P due to scientific and socio-ethical concerns, implies that, even if it were legally possible, the chance that PGT-P would be offered in the near future might be low.

LIMITATIONS, REASONS FOR CAUTION

The results are based on our interpretation of publicly available written information and documents, therefore not all potential discrepancies between law and practice might have been identified. In addition, our analysis focuses on seven-and not all-European countries. However, since these countries are relevant players within PGT in Europe and since they have distinct PGT regulations, the insights gathered give relevant insights into diverse ways of PGT regulation.

WIDER IMPLICATIONS OF THE FINDINGS

To the best of our knowledge, this is the first paper that provides a thorough overview of the legal and practical regulation of PGT in Europe. Our analysis of how PGT-P fits within current regulation models provides guidance for healthcare professionals and policymakers in navigating the possible future implementation of PGT-P within Europe.

STUDY FUNDING/COMPETING INTEREST(S)

This project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 813707. The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Public Attitudes, Interests, and Concerns Regarding Polygenic Embryo Screening

Importance

Polygenic embryo screening (PES) is a novel technology that estimates the likelihood of developing future conditions (eg, diabetes or depression) and traits (eg, height or cognitive ability) in human embryos, with the goal of selecting which embryos to use. Given its commercial availability and concerns raised by researchers, clinicians, bioethicists, and professional organizations, it is essential to inform key stakeholders and relevant policymakers about the public's perspectives on this technology.

Objective

To survey US adults to examine general attitudes, interests, and concerns regarding PES use.

Design, Setting, and Participants

For this survey study, data were collected from 1 stratified sample and 1 nonprobability sample (samples 1 and 2, respectively) between March and July 2023. The surveys measured approval, interest, and concerns regarding various applications of PES. In the second sample, presentation of a list of potential concerns was randomized (presented at survey onset vs survey end). The survey was designed using Qualtrics and distributed to participants through Prolific, an online sampling firm. Sample 1 was nationally representative with respect to gender, age, and race and ethnicity; sample 2 was recruited without specific demographic criteria. Analyses were conducted between March 2023 and February 2024.

Main Outcomes and Measures

Participants reported their approval, interest, and concerns regarding various applications of PES and outcomes screened (eg, traits and conditions). Statistical analysis was conducted using independent samples t tests and repeated-measures analyses of variance.

Results

Of the 1435 respondents in sample 1, demographic data were available for 1427 (mean [SD] age, 45.8 [16.0] years; 724 women [50.7%]). Among these 1427 sample 1 respondents, 1027 (72.0%) expressed approval for PES and 1169 (81.9%) expressed some interest in using PES if already undergoing in vitro fertilization (IVF). Approval among these respondents for using PES for embryo selection was notably high for physical health conditions (1109 [77.7%]) and psychiatric health conditions (1028 [72.0%]). In contrast, there was minority approval for embryo selection based on PES for behavioral traits (514 [36.0%]) and physical traits (432 [30.3%]). Nevertheless, concerns about PES leading to false expectations and promoting eugenic practices were pronounced, with 787 of 1422 (55.3%) and 780 of 1423 (54.8%) respondents finding them very to extremely concerning, respectively. Sample 2 included 192 respondents (mean [SD] age 37.7 [12.2] years; 110 men [57.3%]). These respondents were presented concerns at survey onset (n = 95) vs survey end (n = 97), which was associated with less approval (28-percentage point decrease) and more uncertainty (24 percentage-point increase) but with only slightly higher disapproval (4 percentage-point increase).

Conclusions and Relevance

These findings suggest that it is critical for health care professionals and medical societies to consider and understand the perspectives of diverse stakeholders (eg, patients undergoing IVF, clinicians, and the general public), given the absence of regulation and the recent commercial availability of PES.

Patient interest in and clinician reservations on polygenic embryo screening: a qualitative study of stakeholder perspectives

PURPOSE

We explored and compared perspectives of reproductive endocrinology and infertility specialists (REIs) and in vitro fertilization (IVF) patients regarding polygenic embryo screening (PES), a new type of preimplantation screening that estimates the genetic chances of developing polygenic conditions and traits in the future.

METHODS

Qualitative thematic analysis of semi-structured interviews with US-based REIs and IVF patients.

RESULTS

Clinicians and patients often held favorable views of screening embryos for physical or psychiatric conditions, though clinicians tended to temper their positive attitudes with specific caveats. Clinicians also expressed negative views about screening embryos for traits more frequently than patients, who generally held more positive views. Most clinicians were either unwilling to discuss or offer PES to patients or were willing to do so only under certain circumstances, while many patients expressed interest in PES. Both stakeholder groups envisioned multiple potential benefits or uses of PES and raised multiple potential, interrelated concerns about PES.

CONCLUSION

A gap exists between clinician and patient attitudes toward PES; clinicians generally maintained reservations about such screening and patients indicated interest in it. Clinicians and patients sometimes imagined using PES to prepare for the birth of a predisposed or "affected" individual-a rationale that is often associated with prenatal testing. Many clinicians and patients held different attitudes depending on what is specifically screened, despite the sometimes blurry distinction between conditions and traits. Considerations raised by clinicians and patients may help guide professional societies in developing guidelines to navigate the uncertain terrain of PES.

Shared genetic architectures of educational attainment in East Asian and European populations

Educational attainment (EduYears), a heritable trait often used as a proxy for cognitive ability, is associated with various health and social outcomes. Previous genome-wide association studies (GWASs) on EduYears have been focused on samples of European (EUR) genetic ancestries. Here we present the first large-scale GWAS of EduYears in people of East Asian (EAS) ancestry (n = 176,400) and conduct a cross-ancestry meta-analysis with EduYears GWAS in people of EUR ancestry (n = 766,345). EduYears showed a high genetic correlation and power-adjusted transferability ratio between EAS and EUR. We also found similar functional enrichment, gene expression enrichment and cross-trait genetic correlations between two populations. Cross-ancestry fine-mapping identified refined credible sets with a higher posterior inclusion probability than single population fine-mapping. Polygenic prediction analysis in four independent EAS and EUR cohorts demonstrated transferability between populations. Our study supports the need for further research on diverse ancestries to increase our understanding of the genetic basis of educational attainment.

"Are we not going too far?": Socio-ethical considerations of preimplantation genetic testing using polygenic risk scores according to healthcare professionals

The recent introduction of polygenic risk scores within preimplantation genetic testing (PGT-P) has been met with many concerns. To get more insights into the perspectives of relevant stakeholders on the socio-ethical aspects of PGT-P, an interview study with 31 healthcare professionals involved in reproductive medicine and genetics in Europe and North-America was performed. Healthcare professionals in our study were concerned that PGT-P was going too far in terms of selection, with regards to both medical conditions and non-medical traits. Healthcare professionals were worried about the ethical 'slippery slope' of PGT-P, the increasing medicalization of reproductive health, the commercial context of PGT-P, and potential stigmatization and discrimination. There were also concerns that the availability and the 'technological imperative' of PGT-P could lead to pressure and a sense of responsibility for parents to use PGT-P. Additionally, it could cause new anxieties about the child's health before the child has even been born. Since PGT-P provides polygenic risk scores before birth, the autonomy of the child has to be considered. These socio-ethical concerns heighten existing debates regarding reproductive genetic technologies and show that the specifics of PGT-P make this screening option especially ethically controversial.

Research progress and challenges of preimplantation genetic testing for polygenic diseases

Preimplantation genetic testing is an important part in assisted reproductive technology, which can block the intergenerational inheritance of single gene or chromosomal diseases. Preimplantation genetic testing for polygenic disease risk (PGT-P) is the latest development in the field. It is known that polygenic diseases usually have the characteristics of high incidence, late onset, affecting the quality of life and mental health of patients. On the basis of the development of artificial intelligence and genetic detection technology, PGT-P can analyze genetic material, calculate polygenic risk score turning into incidence probability. Embryos with relatively low incidence probability can be screened for transfer, so as to reduce the possibility of offspring suffering from the disease in the future, which has significant clinical and social significance. At present, PGT-P has been applied clinically and made phased progress at home and abroad. At the same time, as a developing technology, PGT-P still has some technical defects, unstable results, environmental influences and racial differences cannot be ruled out. From the perspective of ethics, if the screening indications are not strictly regulated, it is likely to cause new social problems. In this paper, we review the technical composition and recent progress of PGT-P, and put forward the prospect of its future development, especially how to establish a complete and suitable screening model for Chinese population.

Divergence Between Clinician and Patient Perspectives on Polygenic Embryo Screening: A Qualitative Study

Objective

To explore and compare the perspectives of clinicians and patients on polygenic embryo screening.

Design

Qualitative.

Subjects

Fifty-three participants: 27 reproductive endocrinology and infertility specialists and 26 patients currently undergoing in vitro fertilization or had done so within the last five years.

Main Outcome Measures

Qualitative thematic analysis of interview transcripts.

Results

Both clinicians and patients often held favorable views of screening embryos for physical or psychiatric conditions, though clinicians tended to temper their positive attitudes with specific caveats. Clinicians also expressed negative views about screening embryos for traits more often than patients, who generally held more positive views. Most clinicians were either unwilling to discuss or offer polygenic embryo screening to patients or were willing to do so only under certain circumstances, while many patients expressed interest in polygenic embryo screening. Both sets of stakeholders envisioned multiple potential benefits or uses of polygenic embryo screening; the most common included selection and/or prioritization of embryos, receipt of more information about embryos, and preparation for the birth of a predisposed or "affected" child. Both sets of stakeholders also raised multiple potential, interrelated concerns about polygenic embryo screening. The most common concerns among both sets of stakeholders included the potential for different types of "biases" - most often in relation to selection of embryos with preferred genetic chances of traits -, the probabilistic nature of polygenic embryo screening that can complicate patient counseling and/or lead to excessive cycles of in vitro fertilization, and a lack of data from long-term prospective studies supporting the clinical use of polygenic embryo screening.

Conclusion

Despite patients' interest in polygenic embryo screening, clinicians feel such screening is premature for clinical application. Though now embryos can be screened for their genetic chances of developing polygenic conditions and traits, many clinicians and patients maintain different attitudes depending on what is specifically screened, despite the blurry distinction between conditions and traits. Considerations raised by these stakeholders may help guide professional societies as they consider developing guidelines to navigate the uncertain terrain of polygenic embryo screening, which is already commercially available.

Limitations, concerns and potential: attitudes of healthcare professionals toward preimplantation genetic testing using polygenic risk scores

Preimplantation genetic testing using polygenic risk scores (PGT-P) has recently been introduced. However, PGT-P has been met with many ethical concerns. It is therefore important to get insights into the perspectives of stakeholders regarding PGT-P. We performed a qualitative interview study on the views of healthcare professionals toward PGT-P. We conducted in-depth semi-structured interviews with 31 healthcare professionals working in the field of preimplantation genetic testing. The interviews explored the attitudes of healthcare professionals toward the technology of PGT-P, e.g., the validity, utility, limitations and potential benefits of PGT-P. We found that most healthcare professionals were concerned about the prematurity of introducing PGT-P into clinical practice. They had various ethical considerations, such as concerns related to validity and utility of PGT-P, limited embryos and options, and difficulties for prospective parents regarding comprehension and informed decision-making. Positive aspects were also identified, e.g., regarding reproductive autonomy and potential health benefits. Overall, most healthcare professionals considered that clinical implementation of PGT-P is premature. More comprehensive, longitudinal and inclusive studies are needed first, though these might not improve PGT-P enough to responsibly implement it. Healthcare professionals were also concerned that PGT-P could cause anxiety and create difficult choices for prospective parents. These perspectives and ethical considerations are crucial to consider for future guidelines and recommendations regarding PGT-P.

Neural ADMIXTURE for rapid genomic clustering

Characterizing the genetic structure of large cohorts has become increasingly important as genetic studies extend to massive, increasingly diverse biobanks. Popular methods decompose individual genomes into fractional cluster assignments with each cluster representing a vector of DNA variant frequencies. However, with rapidly increasing biobank sizes, these methods have become computationally intractable. Here we present Neural ADMIXTURE, a neural network autoencoder that follows the same modeling assumptions as the current standard algorithm, ADMIXTURE, while reducing the compute time by orders of magnitude surpassing even the fastest alternatives. One month of continuous compute using ADMIXTURE can be reduced to just hours with Neural ADMIXTURE. A multi-head approach allows Neural ADMIXTURE to offer even further acceleration by calculating multiple cluster numbers in a single run. Furthermore, the models can be stored, allowing cluster assignment to be performed on new data in linear time without needing to share the training samples.

The impact of rare protein coding genetic variation on adult cognitive function

Compelling evidence suggests that human cognitive function is strongly influenced by genetics. Here, we conduct a large-scale exome study to examine whether rare protein-coding variants impact cognitive function in the adult population (n = 485,930). We identify eight genes (ADGRB2, KDM5B, GIGYF1, ANKRD12, SLC8A1, RC3H2, CACNA1A and BCAS3) that are associated with adult cognitive function through rare coding variants with large effects. Rare genetic architecture for cognitive function partially overlaps with that of neurodevelopmental disorders. In the case of KDM5B we show how the genetic dosage of one of these genes may determine the variability of cognitive, behavioral and molecular traits in mice and humans. We further provide evidence that rare and common variants overlap in association signals and contribute additively to cognitive function. Our study introduces the relevance of rare coding variants for cognitive function and unveils high-impact monogenic contributions to how cognitive function is distributed in the normal adult population.

Addressing the ethical and societal challenges posed by genome-wide association studies of behavioral and brain-related traits

Genome-wide association studies have led to the identification of robust statistical associations of genetic variants with numerous brain-related traits, including neurological and psychiatric conditions, and psychological and behavioral measures. These results may provide insight into the biology underlying these traits and may facilitate clinically useful predictions. However, these results also carry the risk of harm, including possible negative effects of inaccurate predictions, violations of privacy, stigma and genomic discrimination, raising serious ethical and legal implications. Here, we discuss ethical concerns surrounding the results of genome-wide association studies for individuals, society and researchers. Given the success of genome-wide association studies and the increasing availability of nonclinical genomic prediction technologies, better laws and guidelines are urgently needed to regulate the storage, processing and responsible use of genetic data. Also, researchers should be aware of possible misuse of their results, and we provide guidance to help avoid such negative impacts on individuals and society.

Assisted reproductive technologies at the nexus of fertility treatment and disease prevention

Assisted reproductive technology (ART) refers to processing gametes in vitro and usually involves in vitro fertilization. Originally developed for the treatment of infertility, culture of human embryos in vitro also provides an opportunity to screen embryos for inherited genetic disorders of the nuclear and mitochondrial genomes. Progress in identifying causative genetic variants has massively increased the scope of preimplantation genetic testing in preventing genetic disorders. However, because ART procedures are not without risk of adverse maternal and child outcomes, careful consideration of the balance of risks and benefits is warranted. Further research on early human development will help to minimize risks while maximizing the benefits of ART.

Polygenic Scores in the Direct-to-Consumer Setting: Challenges and Opportunities for a New Era in Consumer Genetic Testing

Direct-to-consumer (DTC) genetic tests have generated considerable scholarly attention and public intrigue. Although the current consumer genetic testing regime relies on the reporting of individual variants of interest to consumers, there has recently been interest in the possibility of integrating polygenic scores (PGS), which aggregate genetic liability for disease across the entire genome. While PGS have thus far been extensively explored as clinical and public health tools, the use of PGS in consumer genetic testing has not yet received systematic attention, even though they are already in use for some consumer genetic tests. In this narrative review, we highlight the ethical, legal, and social implications of the use of PGS in DTC genetic tests and synthesize existing solutions to these concerns. We organize these concerns into three domains: (1) industry variation; (2) privacy and commercialization; and (3) patient safety and risk. While previously expressed concerns in these domains will remain relevant, the emergence of PGS-based DTC genetic tests raises challenges that will require novel approaches.

The New Social Contract for Genomics

The belief that genomics requires rethinking the 'social contract' to realize its potential has received backing from leading figures within bioethics. The case for a new social contract is anchored in notions of solidarity, altruism or the common good. But national genome sequencing is playing out against a backdrop of greatly increased involvement, and investment, of governments in their life science sectors - creating a sort of international race to drive innovation, stimulate growth, and create the most competitive life science sectors. Recent developments in the UK suggest this agenda is detrimental to openness and transparency, as well as independent oversight, and meaningful public consultation. These aspects of governance, I argue, should be reconceived as part of the requirements of good governance. Further, a new social contract should involve a commitment by government, and industry, to educate the public about life science - and should be extended to life science more generally.

Germline Gene Editing: The Gender Issues

Human germline gene editing constitutes an extremely promising technology; at the same time, however, it raises remarkable ethical, legal, and social issues. Although many of these issues have been largely explored by the academic literature, there are gender issues embedded in the process that have not received the attention they deserve. This paper examines ways in which this new tool necessarily affects males and females differently-both in rewards and perils. The authors conclude that there is an urgent need to include these gender issues in the current debate, before giving a green light to this new technology.

Public views on polygenic screening of embryos

Understanding moral acceptability and willingness to use is crucial for informing policy.

Sibling variation in polygenic traits and DNA recombination mapping with UK Biobank and IVF family data

We use UK Biobank and a unique IVF family dataset (including genotyped embryos) to investigate sibling variation in both phenotype and genotype. We compare phenotype (disease status, height, blood biomarkers) and genotype (polygenic scores, polygenic health index) distributions among siblings to those in the general population. As expected, the between-siblings standard deviation in polygenic scores is [Formula: see text] times smaller than in the general population, but variation is still significant. As previously demonstrated, this allows for substantial benefit from polygenic screening in IVF. Differences in sibling genotypes result from distinct recombination patterns in sexual reproduction. We develop a novel sibling-pair method for detection of recombination breaks via statistical discontinuities. The new method is used to construct a dataset of 1.44 million recombination events which may be useful in further study of meiosis.

Gattaca as a lens on contemporary genetics: marking 25 years into the film's "not-too-distant" future

The 1997 film Gattaca has emerged as a canonical pop culture reference used to discuss modern controversies in genetics and bioethics. It appeared in theaters a few years prior to the announcement of the "completion" of the human genome (2000), as the science of human genetics was developing a renewed sense of its social implications. The story is set in a near-future world in which parents can, with technological assistance, influence the genetic composition of their offspring on the basis of predicted life outcomes. The current moment-25 years after the film's release-offers an opportunity to reflect on where society currently stands with respect to the ideas explored in Gattaca. Here, we review and discuss several active areas of genetic research-genetic prediction, embryo selection, forensic genetics, and others-that interface directly with scenes and concepts in the film. On its silver anniversary, we argue that Gattaca remains an important reflection of society's expectations and fears with respect to the ways that genetic science has manifested in the real world. In accompanying supplemental material, we offer some thought questions to guide group discussions inside and outside of the classroom.

Psychiatric polygenic risk scores: Child and adolescent psychiatrists' knowledge, attitudes, and experiences

Psychiatric polygenic risk scores (PRS) have potential utility in psychiatric care and prevention, but there are concerns about their implementation. We surveyed 960 US-based practicing child and adolescent psychiatrists' (CAP) about their experiences, perspectives, and potential uses of psychiatric PRS. While 23% of CAP reported that they had never heard of PRS, 10 % of respondents have had a patient/family bring PRS to them and 4% have generated PRS for patients. Though 25% stated they would request PRS if a patient/caregiver asked, 35% indicated that nothing would prompt them to request PRS. Most respondents (54%) believed psychiatric PRS are currently at least slightly useful and 87% believed they will be so in 5 years. More than 70% indicated they would take action in response to a child with a top fifth percentile psychiatric PRS but no diagnosis: 48% would increase monitoring of symptoms, 42% would evaluate for current symptoms, and 4% would prescribe medications. Yet, most respondents were concerned that high-PRS results could lead to overtreatment and negatively impact patients' emotional well-being. Findings indicate emerging use of psychiatric PRS within child and adolescent psychiatry in the US. It is critical to examine the ethical and clinical challenges that PRS may generate and begin efforts to promote their informed and responsible use.

Concerns about the use of polygenic embryo screening for psychiatric and cognitive traits

Private companies have begun offering services to allow parents undergoing in-vitro fertilisation to screen embryos for genetic risk of complex diseases, including psychiatric disorders. This procedure, called polygenic embryo screening, raises several difficult scientific and ethical issues, as discussed in this Personal View. Polygenic embryo screening depends on the statistical properties of polygenic risk scores, which are complex and not well studied in the context of this proposed clinical application. The clinical, social, and ethical implications of polygenic embryo screening have barely been discussed among relevant stakeholders. To our knowledge, the International Society of Psychiatric Genetics is the first professional biomedical organisation to issue a statement regarding polygenic embryo screening. For the reasons discussed in this Personal View, the Society urges caution and calls for additional research and oversight on the use of polygenic embryo screening.

SALAI-Net: species-agnostic local ancestry inference network

MOTIVATION

Local ancestry inference (LAI) is the high resolution prediction of ancestry labels along a DNA sequence. LAI is important in the study of human history and migrations, and it is beginning to play a role in precision medicine applications including ancestry-adjusted genome-wide association studies (GWASs) and polygenic risk scores (PRSs). Existing LAI models do not generalize well between species, chromosomes or even ancestry groups, requiring re-training for each different setting. Furthermore, such methods can lack interpretability, which is an important element in each of these applications.

RESULTS

We present SALAI-Net, a portable statistical LAI method that can be applied on any set of species and ancestries (species-agnostic), requiring only haplotype data and no other biological parameters. Inspired by identity by descent methods, SALAI-Net estimates population labels for each segment of DNA by performing a reference matching approach, which leads to an interpretable and fast technique. We benchmark our models on whole-genome data of humans and we test these models' ability to generalize to dog breeds when trained on human data. SALAI-Net outperforms previous methods in terms of balanced accuracy, while generalizing between different settings, species and datasets. Moreover, it is up to two orders of magnitude faster and uses considerably less RAM memory than competing methods.

AVAILABILITY AND IMPLEMENTATION

We provide an open source implementation and links to publicly available data at github.com/AI-sandbox/SALAI-Net. Data is publicly available as follows: https://www.internationalgenome.org (1000 Genomes), https://www.simonsfoundation.org/simons-genome-diversity-project (Simons Genome Diversity Project), https://www.sanger.ac.uk/resources/downloads/human/hapmap3.html (HapMap), ftp://ngs.sanger.ac.uk/production/hgdp/hgdp_wgs.20190516 (Human Genome Diversity Project) and https://www.ncbi.nlm.nih.gov/bioproject/PRJNA448733 (Canid genomes).

SUPPLEMENTARY INFORMATION

Supplementary data are available from Bioinformatics online.

Genetic risk factors have a substantial impact on healthy life years

The impact of genetic variation on overall disease burden has not been comprehensively evaluated. We introduce an approach to estimate the effect of genetic risk factors on disability-adjusted life years (DALYs; 'lost healthy life years'). We use genetic information from 735,748 individuals and consider 80 diseases. Rare variants had the highest effect on DALYs at the individual level. Among common variants, rs3798220 (LPA) had the strongest individual-level effect, with 1.18 DALYs from carrying 1 versus 0 copies. Being in the top 10% versus the bottom 90% of a polygenic score for multisite chronic pain had an effect of 3.63 DALYs. Some common variants had a population-level effect comparable to modifiable risk factors such as high sodium intake and low physical activity. Attributable DALYs vary between males and females for some genetic exposures. Genetic risk factors can explain a sizable number of healthy life years lost both at the individual and population level.

Polygenic scores in biomedical research

Public health strategies aimed at disease prevention or early detection and intervention have the potential to advance human health worldwide. However, their success depends on the identification of risk factors that underlie disease burden in the general population. Genome-wide association studies (GWAS) have implicated thousands of single-nucleotide polymorphisms (SNPs) in common complex diseases or traits. By calculating a weighted sum of the number of trait-associated alleles harboured by an individual, a polygenic score (PGS), also called a polygenic risk score (PRS), can be constructed that reflects an individual’s estimated genetic predisposition for a given phenotype. Here, we ask six experts to give their opinions on the utility of these probabilistic tools, their strengths and limitations, and the remaining barriers that need to be overcome for their equitable use.

Challenges and Opportunities for Developing More Generalizable Polygenic Risk Scores

Polygenic risk scores (PRS) estimate an individual's genetic likelihood of complex traits and diseases by aggregating information across multiple genetic variants identified from genome-wide association studies. PRS can predict a broad spectrum of diseases and have therefore been widely used in research settings. Some work has investigated their potential applications as biomarkers in preventative medicine, but significant work is still needed to definitively establish and communicate absolute risk to patients for genetic and modifiable risk factors across demographic groups. However, the biggest limitation of PRS currently is that they show poor generalizability across diverse ancestries and cohorts. Major efforts are underway through methodological development and data generation initiatives to improve their generalizability. This review aims to comprehensively discuss current progress on the development of PRS, the factors that affect their generalizability, and promising areas for improving their accuracy, portability, and implementation.

Polygenic risk score for embryo selection—not ready for prime time

Numerous chronic diseases have a substantial hereditary component. Recent advances in human genetics have allowed the extent of this to be quantified via genome-wide association studies, producing polygenic risk scores (PRS), which can then be applied to individuals to estimate their risk of developing a disease in question. This technology has recently been applied to embryo selection in the setting of IVF and preimplantation genetic testing, with limited data to support its utility. Furthermore, there are concerns that the inherent limitations of PRS makes it ill-suited for use as a screening test in this setting. There are also serious ethical and moral questions associated with this technology that are yet to be addressed. We conclude that further research and ethical reflection are required before embryo selection based on PRS is offered to patients outside of the research setting.

Polygenic embryo screening: four clinical considerations warrant further attention

Recent advances in developing polygenic scores have made it possible to screen embryos for common, complex conditions and traits. Polygenic embryo screening (PES) is currently offered commercially, and though there has been much recent media and academic coverage, reproductive specialists' points of view have not yet been prominent in these discussions. We convened a roundtable of multidisciplinary experts, including reproductive specialists to discuss PES and its implications. In this Opinion, we describe four clinically relevant issues associated with the use of PES that have not yet been discussed in the literature and warrant consideration.

A review of normative documents on preimplantation genetic testing: Recommendations for PGT-P

PURPOSE

Recently, preimplantation genetic testing (PGT) for polygenic conditions (PGT-P) has been introduced commercially. In view of the lack of specific guidance on this development, we analyzed normative documents on PGT for monogenic conditions (PGT-M) to understand what we can learn from these documents for recommendations for PGT-P.

METHODS

We conducted a systematic review of normative guidelines and recommendations on PGT-M. The aim was to understand what the current consensus and disagreements are on ethical acceptability of PGT-M and how this compares with PGT-P.

RESULTS

We analyzed 38 documents by advisory committees at the national, European, and global level. In total, 2 themes were identified, which included the following: (1) what PGT is considered appropriate for and (2) who can make decisions regarding the use of PGT. Many aspects of PGT-M documents apply to PGT-P as well. Additional factors such as the fact that PGT-P screens for risk indications of multiple polygenic conditions increase ethical difficulties regarding severity, risk, autonomy, and informed decision-making.

CONCLUSION

On the basis of PGT-M normative documents, we conclude that ethical acceptability for PGT-P is limited. Our findings present various factors that have to be considered for the development of guidelines and the appropriateness of PGT.

Investigating the feasibility and ethical implications of phenotypic screening using stem cell-derived tissue models to detect and manage disease

Stem-cell-derived tissue models generated from sick people are being used to understand human development and disease, drug development, and drug screening. However, it is possible to detect disease phenotypes before a patient displays symptoms, allowing for their use as a disease screening tool. This raises numerous issues, some of which can be addressed using similar approaches from genetic screenings, while others are unique. One issue is the relationship between disease disposition, biomarker detection, and patient symptoms and how tissue models could be used to define disease. Other issues include decisions of when to screen, what diseases to screen for, and what treatment options should be offered.

ISPD 2021 Debate - All IVF cycles should involve pre-implantation genetic testing to improve fetal health and pregnancy outcomes

For three decades, couples at increased risk for a genetic disorder have been offered preimplantation genetic testing (PGT). Simultaneously, PGT for aneuploidy (PGT-A) to improve in vitro fertilization (IVF) outcomes was introduced, but evidence of value-added remains inconsistent. Recently, lower genetic testing costs and shorter turnaround time have reinvigorated PGT-A. Additionally, a shift from blastomere (day 3) to blastocyst (day 5) transfer and embryo freezing advances support PGT without the time constraints of immediate transfer. PGT-A transformed from a time-constrained analysis of 1-2 cells to an "add on" study for all IVF. But should it be offered to all IVF patients? And if not, under what conditions? Pre-debate polling found 64% opposed to PGT for all IVF cycles with concerns voiced about cost, informed consent, and a "slippery slope". Leaving aside the inconsistent evidence of IVF improvement whether measured as miscarriage or livebirths with PGT-A, the debaters grappled with patient and provider desires versus the ethical concerns for the unborn child. However, the audience was not swayed; two thirds remained opposed to PGT for all IVF cycles. This article is protected by copyright. All rights reserved.

Whole-genome risk prediction of common diseases in human preimplantation embryos

Preimplantation genetic testing (PGT) of in-vitro-fertilized embryos has been proposed as a method to reduce transmission of common disease; however, more comprehensive embryo genetic assessment, combining the effects of common variants and rare variants, remains unavailable. Here, we used a combination of molecular and statistical techniques to reliably infer inherited genome sequence in 110 embryos and model susceptibility across 12 common conditions. We observed a genotype accuracy of 99.0–99.4% at sites relevant to polygenic risk scoring in cases from day-5 embryo biopsies and 97.2–99.1% in cases from day-3 embryo biopsies. Combining rare variants with polygenic risk score (PRS) magnifies predicted differences across sibling embryos. For example, in a couple with a pathogenic BRCA1 variant, we predicted a 15-fold difference in odds ratio (OR) across siblings when combining versus a 4.5-fold or 3-fold difference with BRCA1 or PRS alone. Our findings may inform the discussion of utility and implementation of genome-based PGT in clinical practice.

A computational approach combining whole-genome sequencing of parental genomes and genotyping of preimplantation embryos allows accurate prediction of the inherited genomes of embryos and calculation of polygenic risk scores.

Testing the talented child: Direct-to-consumer genetic talent tests in China

One controversial area of direct-to-consumer genetic testing in China is "genetic talent testing" for children. In this study, I show that while experts criticize genetic talent testing as unscientific, the persistence of genetic talent testing is not merely a product of parents' scientific illiteracy. Instead, genetic talent testing reflects parents' pragmatic use of technology in response to the parenting pressures in contemporary China. Parents see the results of genetic talent testing as offering an advantage for their children when combined with the intensive parenting strategy of precision education. Drawing on the sociology of testing, I argue how genetic talent testing in China is a product of broader concerns about population quality and can potentially reshape how parents imagine quality children through the theory of multiple intelligences. My study of this "off label" use of direct-to-consumer genetic testing also suggests that scientists need to broaden their imagination of potential misuses of their technologies.

A systematic review of the views of healthcare professionals on the scope of preimplantation genetic testing

Preimplantation genetic testing (PGT) involves testing embryos created through in vitro fertilization for the presence of hereditary genetic disorders and chromosome abnormalities. PGT for monogenic conditions (PGT-M) is generally performed for childhood-onset, lethal disorders, but is increasingly accepted for certain adult-onset conditions, conditions with available treatment options or conditions with lower penetrance. Furthermore, the development of PGT for polygenic conditions (PGT-P) makes ethical questions regarding PGT indications imperative. A systematic review was therefore performed to gather and analyse studies on the perspectives of healthcare professionals on the appropriate scope of PGT, with the aim of getting insights into the concerns about the scope of PGT now and in the near future. PRISMA guidelines were followed. Twelve qualitative articles were included. The main themes extracted were the scope of PGT and decision-making about PGT. Defining 'a serious genetic condition' was seen as complex, but severity, high penetrance and absence of treatability and patients' experience were seen as relevant indications to determine the appropriateness of PGT. In navigating the decision-making processes with patients, professionals experienced friction between setting limits and respecting patients' autonomy. Such friction and ethical dilemmas around seriousness, informed decision-making and preventative medicine show that while expanding the list of possible PGT indications and the development of PGT-P could augment patients' reproductive autonomy, it could also lead to an increased reproductive 'burden' for patients. These insights are crucial for establishing guidelines that help healthcare professionals navigate ethical tensions associated with PGT.

Ancestry may confound genetic machine learning: Candidate-gene prediction of opioid use disorder as an example

BACKGROUND

Machine learning (ML) models are beginning to proliferate in psychiatry, however machine learning models in psychiatric genetics have not always accounted for ancestry. Using an empirical example of a proposed genetic test for OUD, and exploring a similar test for tobacco dependence and a simulated binary phenotype, we show that genetic prediction using ML is vulnerable to ancestral confounding.

METHODS

We utilize five ML algorithms trained with 16 brain reward-derived "candidate" SNPs proposed for commercial use and examine their ability to predict OUD vs. ancestry in an out-of-sample test set (N = 1000, stratified into equal groups of n = 250 cases and controls each of European and African ancestry). We rerun analyses with 8 random sets of allele-frequency matched SNPs. We contrast findings with 11 genome-wide significant variants for tobacco smoking. To document generalizability, we generate and test a random phenotype.

RESULTS

None of the 5 ML algorithms predict OUD better than chance when ancestry was balanced but were confounded with ancestry in an out-of-sample test. In addition, the algorithms preferentially predicted admixed subpopulations. Random sets of variants matched to the candidate SNPs by allele frequency produced similar bias. Genome-wide significant tobacco smoking variants were also confounded by ancestry. Finally, random SNPs predicting a random simulated phenotype show that the bias attributable to ancestral confounding could impact any ML-based genetic prediction.

CONCLUSIONS

Researchers and clinicians are encouraged to be skeptical of claims of high prediction accuracy from ML-derived genetic algorithms for polygenic traits like addiction, particularly when using candidate variants.

Utility of polygenic embryo screening for disease depends on the selection strategy

Polygenic risk scores (PRSs) have been offered since 2019 to screen in vitro fertilization embryos for genetic liability to adult diseases, despite a lack of comprehensive modeling of expected outcomes. Here we predict, based on the liability threshold model, the expected reduction in complex disease risk following polygenic embryo screening for a single disease. A strong determinant of the potential utility of such screening is the selection strategy, a factor that has not been previously studied. When only embryos with a very high PRS are excluded, the achieved risk reduction is minimal. In contrast, selecting the embryo with the lowest PRS can lead to substantial relative risk reductions, given a sufficient number of viable embryos. We systematically examine the impact of several factors on the utility of screening, including: variance explained by the PRS, number of embryos, disease prevalence, parental PRSs, and parental disease status. We consider both relative and absolute risk reductions, as well as population-averaged and per-couple risk reductions, and also examine the risk of pleiotropic effects. Finally, we confirm our theoretical predictions by simulating 'virtual' couples and offspring based on real genomes from schizophrenia and Crohn's disease case-control studies. We discuss the assumptions and limitations of our model, as well as the potential emerging ethical concerns.

Polygenic risk scoring of human embryos: a qualitative study of media coverage

BACKGROUND

Current preimplantation genetic testing (PGT) technologies enable embryo genotyping across the whole genome. This has led to the development of polygenic risk scoring of human embryos (PGT-P). Recent implementation of PGT-P, including screening for intelligence, has been extensively covered by media reports, raising major controversy. Considering the increasing demand for assisted reproduction, we evaluated how information about PGT-P is communicated in press media and explored the diversity of ethical themes present in the public debate.

METHODS

LexisNexis Academic database and Google News were searched to identify articles about polygenic embryo screening. This led to 535 news articles. 59 original articles met the inclusion criteria. Inductive content analysis was used to analyse these articles.

RESULTS

8.8% of articles gave embryo polygenic scoring a positive portrayal, while 36.8% expressed a negative attitude. 54.4% were neutral, mostly highlighting limited practical value of the technology in in vitro fertilization settings. We identified five main ethical themes that are also present in academic literature and the broader debate on reproductive technologies: a slippery slope towards designer babies, well-being of the child and parents, impact on society, deliberate choice and societal readiness.

CONCLUSIONS

Implementation of embryo polygenic profiling engenders a need for specific recommendations. Current media analysis discloses important ethical themes to consider when creating future guidelines for PGT-P.

Problems with Using Polygenic Scores to Select Embryos

Companies have recently begun to sell a new service to patients considering in vitro fertilization: embryo selection based on polygenic scores (ESPS). These scores represent individualized predictions of health and other outcomes derived from genomewide association studies in adults to partially predict these outcomes. This article includes a discussion of many factors that lower the predictive power of polygenic scores in the context of embryo selection and quantifies these effects for a variety of clinical and nonclinical traits. Also discussed are potential unintended consequences of ESPS (including selecting for adverse traits, altering population demographics, exacerbating inequalities in society, and devaluing certain traits). Recommendations for the responsible communication about ESPS by practitioners are provided, and a call for a society-wide conversation about this technology is made. (Funded by the National Institute on Aging and others.).

Estimating genetic nurture with summary statistics of multigenerational genome-wide association studies

Marginal effect estimates in genome-wide association studies (GWAS) are mixtures of direct and indirect genetic effects. Existing methods to dissect these effects require family-based, individual-level genetic, and phenotypic data with large samples, which is difficult to obtain in practice. Here, we propose a statistical framework to estimate direct and indirect genetic effects using summary statistics from GWAS conducted on own and offspring phenotypes. Applied to birth weight, our method showed nearly identical results with those obtained using individual-level data. We also decomposed direct and indirect genetic effects of educational attainment (EA), which showed distinct patterns of genetic correlations with 45 complex traits. The known genetic correlations between EA and higher height, lower body mass index, less-active smoking behavior, and better health outcomes were mostly explained by the indirect genetic component of EA. In contrast, the consistently identified genetic correlation of autism spectrum disorder (ASD) with higher EA resides in the direct genetic component. A polygenic transmission disequilibrium test showed a significant overtransmission of the direct component of EA from healthy parents to ASD probands. Taken together, we demonstrate that traditional GWAS approaches, in conjunction with offspring phenotypic data collection in existing cohorts, could greatly benefit studies on genetic nurture and shed important light on the interpretation of genetic associations for human complex traits.

Statistical genetics and polygenic risk score for precision medicine

The prediction of disease risks is an essential part of personalized medicine, which includes early disease detection, prevention, and intervention. The polygenic risk score (PRS) has become the standard for quantifying genetic liability in predicting disease risks. PRS utilizes single-nucleotide polymorphisms (SNPs) with genetic risks elucidated by genome-wide association studies (GWASs) and is calculated as weighted sum scores of these SNPs with genetic risks using their effect sizes from GWASs as their weights. The utilities of PRS have been explored in many common diseases, such as cancer, coronary artery disease, obesity, and diabetes, and in various non-disease traits, such as clinical biomarkers. These applications demonstrated that PRS could identify a high-risk subgroup of these diseases as a predictive biomarker and provide information on modifiable risk factors driving health outcomes. On the other hand, there are several limitations to implementing PRSs in clinical practice, such as biased sensitivity for the ethnic background of PRS calculation and geographical differences even in the same population groups. Also, it remains unclear which method is the most suitable for the prediction with high accuracy among numerous PRS methods developed so far. Although further improvements of its comprehensiveness and generalizability will be needed for its clinical implementation in the future, PRS will be a powerful tool for therapeutic interventions and lifestyle recommendations in a wide range of diseases. Thus, it may ultimately improve the health of an entire population in the future.

Affecting future individuals: Why and when germline genome editing entails a greater moral obligation towards progeny

Assisted reproductive technologies have greatly increased our control over reproductive choices, leading some bioethicists to argue that we face unprecedented moral obligations towards progeny. Several models attempting to balance the principle of procreative autonomy with these obligations have been proposed. The least demanding is the minimal threshold model (MTM), according to which every reproductive choice is permissible, except creating children whose lives will not be worth living. Hence, as long as the future child is likely to have a life worth living, prospective parents may be allowed to use preimplantation genetic diagnosis (PGD) to select embryos with genetic diseases or disabilities. Assuming a consequentialist person-affecting view of morality, this paper investigates whether the MTM is an appropriate tool to guide procreative decisions given the continuous development of reproductive genetic technologies. In particular, I consider germline genome editing (GGE) and I argue that its application in human reproduction, unlike PGD, should be conceived as person-affecting towards future progeny. I claim that even if we assume the plausibility of the MTM within PGD, we are committed to accepting that a greater moral obligation towards progeny should guide procreative decisions if GGE were available. In this case, the MTM should no longer be considered an appropriate instrument to guide procreative choices. Finally, I investigate when we face this greater moral obligation, concluding that it applies only when prospective parents have already engaged in the in vitro fertilization process.

Polygenic risk scores in the clinic: new perspectives needed on familiar ethical issues

Clinical use of polygenic risk scores (PRS) will look very different to the more familiar monogenic testing. Here we argue that despite these differences, most of the ethical, legal, and social issues (ELSI) raised in the monogenic setting, such as the relevance of results to family members, the approach to secondary and incidental findings, and the role of expert mediators, continue to be relevant in the polygenic context, albeit in modified form. In addition, PRS will reanimate other old debates. Their use has been proposed both in the practice of clinical medicine and of public health, two contexts with differing norms. In each of these domains, it is unclear what endpoints clinical use of PRS should aim to maximize and under what constraints. Reducing health disparities is a key value for public health, but clinical use of PRS could exacerbate race-based health disparities owing to differences in predictive power across ancestry groups. Finally, PRS will force a reckoning with pre-existing questions concerning biomarkers, namely the relevance of self-reported race, ethnicity and ancestry, and the relationship of risk factors to disease diagnoses. In this Opinion, we argue that despite the parallels to the monogenic setting, new work is urgently needed to gather data, consider normative implications, and develop best practices around this emerging branch of genomics.