LlamaTags: A Versatile Tool to Image Transcription Factor Dynamics in Live Embryos.

Embryonic cell fates are defined by transcription factors that are rapidly deployed, yet attempts to visualize these factors in vivo often fail because of slow fluorescent protein maturation. Here, we pioneer a protein tag, LlamaTag, which circumvents this maturation limit by binding mature fluorescent proteins, making it possible to visualize transcription factor concentration dynamics in live embryos. Implementing this approach in the fruit fly Drosophila melanogaster, we discovered stochastic bursts in the concentration of transcription factors that are correlated with bursts in transcription. We further used LlamaTags to show that the concentration of protein in a given nucleus heavily depends on transcription of that gene in neighboring nuclei; we speculate that this inter-nuclear signaling is an important mechanism for coordinating gene expression to delineate straight and sharp boundaries of gene expression. Thus, LlamaTags now make it possible to visualize the flow of information along the central dogma in live embryos.

Opportunities and challenges for the computational interpretation of rare variation in clinically important genes.

Genome sequencing is enabling precision medicine-tailoring treatment to the unique constellation of variants in an individual's genome. The impact of recurrent pathogenic variants is often understood, however there is a long tail of rare genetic variants that are uncharacterized. The problem of uncharacterized rare variation is especially acute when it occurs in genes of known clinical importance with functionally consequential variants and associated mechanisms. Variants of uncertain significance (VUSs) in these genes are discovered at a rate that outpaces current ability to classify them with databases of previous cases, experimental evaluation, and computational predictors. Clinicians are thus left without guidance about the significance of variants that may have actionable consequences. Computational prediction of the impact of rare genetic variation is increasingly becoming an important capability. In this paper, we review the technical and ethical challenges of interpreting the function of rare variants in two settings: inborn errors of metabolism in newborns and pharmacogenomics. We propose a framework for a genomic learning healthcare system with an initial focus on early-onset treatable disease in newborns and actionable pharmacogenomics. We argue that (1) a genomic learning healthcare system must allow for continuous collection and assessment of rare variants, (2) emerging machine learning methods will enable algorithms to predict the clinical impact of rare variants on protein function, and (3) ethical considerations must inform the construction and deployment of all rare-variation triage strategies, particularly with respect to health disparities arising from unbalanced ancestry representation.

The difficulties of broad data sharing in genomic medicine: Empirical evidence from diverse participants in prenatal and pediatric clinical genomics research.

PURPOSE: This study aimed to understand broad data sharing decisions among predominantly underserved families participating in genomic research. METHODS: Drawing on clinic observations, semistructured interviews, and survey data from prenatal and pediatric families enrolled in a genomic medicine study focused on historically underserved and underrepresented populations, this paper expands empirical evidence regarding genomic data sharing communication and decision-making. RESULTS: One-third of parents declined to share family data, and pediatric participants were significantly more likely to decline than prenatal participants. The pediatric population was significantly more socioeconomically disadvantaged and more likely to require interpreters. Opt-in was tied to altruism and participants' perception that data sharing was inherent to research participation. Opt-out was associated with privacy concerns and influenced by clinical staff's presentation of data handling procedures. The ability of participants to make informed choices during enrollment about data sharing was weakened by suboptimal circumstances, which was revealed by poor understanding of data sharing in follow-up interviews as well as discrepancies between expressed participant desires and official recorded choices. CONCLUSION: These empirical data suggest that the context within which informed consent process is conducted in clinical genomics may be inadequate for respecting participants' values and preferences and does not support informed decision-making processes.

Perspectives and preferences regarding genomic secondary findings in underrepresented prenatal and pediatric populations: A mixed-methods approach.

PURPOSE: Patients undergoing clinical exome sequencing (ES) are routinely offered the option to receive secondary findings (SF). However, little is known about the views of individuals from underrepresented minority pediatric or prenatal populations regarding SF. METHODS: We explored the preferences for receiving hypothetical categories of SF (H-SF) and reasons for accepting or declining actual SF through surveying (n = 149) and/or interviewing (n = 47) 190 families undergoing pediatric or prenatal ES. RESULTS: Underrepresented minorities made up 75% of the probands. In total, 150 families (79%) accepted SF as part of their child/fetus's ES. Most families (63%) wanted all categories of H-SF. Those who declined SF as part of ES were less likely to want H-SF across all categories. Interview findings indicate that some families did not recall their SF decision. Preparing for the future was a major motivator for accepting SF, and concerns about privacy, discrimination, and psychological effect drove decliners. CONCLUSION: A notable subset of families (37%) did not want at least 1 category of H-SF, suggesting more hesitancy about receiving all available results than previously reported. The lack of recollection of SF decisions suggests a need for alternative communication approaches. Results highlight the importance of the inclusion of diverse populations in genomic research.

Experts' Views on Children's Access to Community-Based Therapeutic and Education Services After Genomic Sequencing Results.

OBJECTIVE: To evaluate how community-based experts respond to families seeking therapeutic and educational support services after pediatric genomic sequencing for rare conditions. METHODS: We interviewed 15 experts in the provision of community-based services for children with intellectual differences, developmental differences, or both, as part of a large study examining the utility of exome sequencing. RESULTS: Interviewees highlighted the complexity of the overall referral and assessment system for therapeutic or educational needs, that genetic diagnoses are secondary to behavioral observations in respect to eligibility for the provision of services, and that social capital drives service acquisition. Although emphasizing that genetic results do not currently provide sufficient information for determining service eligibility, interviewees also highlighted their hopes that genetics would be increasingly relevant in the future. CONCLUSION: Genomic results do not usually provide information that directly impacts service provision. However, a positive genomic test result can strengthen evidence for behavioral diagnoses and the future trajectory of a child's condition and support needs. Interviewees' comments suggest a need to combine emerging genetic knowledge with existing forms of therapeutic and educational needs assessment, and for additional supports for families struggling to navigate social and therapeutic services.

The Need to Standardize the Reanalysis of Genomic Sequencing Results: Findings from Interviews with Underserved Families in Genomic Research.

The reanalysis of genomic sequencing results has the potential to provide results that are of considerable medical and personal importance to recipients. Employing interviews with forty-seven predominantly medically underserved families and ethnographic observations we argue that there is pressing need to standardize the approach taken to reanalysis. Our findings highlight that study participants were unclear as to the likelihood of reanalysis happening, the process of initiating reanalysis, and whether they would receive revised results. Their reflections mirror the lack a specific focus upon reanalysis within consent and results sessions as observed in clinical settings. Mechanisms need to be put into place that standardize the approach to reanalysis in research and in clinical contexts. This would enable clinicians and genetic counsellors to communicate clearly with research participants with respect to potential for reanalysis of results and the process of reanalysis. We argue that that the role of reanalysis is too important to be referred to in an ad-hoc manner. Furthermore, the ad-hoc nature of the current process may increase health inequities given the likelihood that only those families who have the means to press for reanalysis are likely to receive it.

A bistable autoregulatory module in the developing embryo commits cells to binary expression fates.

Bistable autoactivation has been proposed as a mechanism for cells to adopt binary fates during embryonic development. However, it is unclear whether the autoactivating modules found within developmental gene regulatory networks are bistable, unless their parameters are quantitatively determined. Here, we combine in vivo live imaging with mathematical modeling to dissect the binary cell fate dynamics of the fruit fly pair-rule gene fushi tarazu (ftz), which is regulated by two known enhancers: the early (non-autoregulating) element and the autoregulatory element. Live imaging of transcription and protein concentration in the blastoderm revealed that binary Ftz fates are achieved as Ftz expression rapidly transitions from being dictated by the early element to the autoregulatory element. Moreover, we discovered that Ftz concentration alone is insufficient to activate the autoregulatory element, and that this element only becomes responsive to Ftz at a prescribed developmental time. Based on these observations, we developed a dynamical systems model and quantitated its kinetic parameters directly from experimental measurements. Our model demonstrated that the ftz autoregulatory module is indeed bistable and that the early element transiently establishes the content of the binary cell fate decision to which the autoregulatory module then commits. Further in silico analysis revealed that the autoregulatory element locks the Ftz fate quickly, within 35 min of exposure to the transient signal of the early element. Overall, our work confirms the widely held hypothesis that autoregulation can establish developmental fates through bistability and, most importantly, provides a framework for the quantitative dissection of cellular decision-making.

The Challenge of Recruiting Diverse Populations into Health Research: An embedded social science perspective.

Addressing health disparities has become a central remit for conducting health research. In the following paper, we explore the conceptual and methodological challenges posed by the call to recruit medically underserved populations. This exploration of challenges is undertaken from the perspective of social science researchers embedded in a large within a clinical genomics research study. We suggest that these challenges are found in respect to the development of recruiting strategies, analysis of the data in respect to understanding and interpreting the experiences of being medically underserved, and in comparing the experiences of being medically underserved compared to not being underserved. By way of conclusion, it is argued that there is important role for social scientists with large health research studies which, if achieved successfully, can benefit study teams and society as a whole.

"Let's Just Wait Until She's Born": Temporal Factors That Shape Decision-Making for Prenatal Genomic Sequencing Amongst Families Underrepresented in Genomic Research.

Genomic sequencing has been increasingly utilized for prenatal diagnosis in recent years and this trend is likely to continue. However, decision-making for parents in the prenatal period is particularly fraught, and prenatal sequencing would significantly expand the complexity of managing health risk information, reproductive options, and healthcare access. This qualitative study investigates decision-making processes amongst parents who enrolled or declined to enroll in the prenatal arm of the California-based Program in Prenatal and Pediatric Genome Sequencing (P3EGS), a study in the Clinical Sequencing Evidence-Generating Research (CSER) consortium that offered whole exome sequencing for fetal anomalies with a focus on underrepresented groups in genomic research. Drawing on the views of 18 prenatal families who agreed to be interviewed after enrolling (n = 15) or declining to enroll (n = 3) in P3EGS, we observed that the timing of sequencing, coupled with unique considerations around experiences of time during pregnancy and prenatal testing, intersect with structural supports beyond the clinic to produce preferences for and against prenatal sequencing and to contain the threat of unwelcome, uncertain knowledge. Particularly for those without structural supports, finding out consequential information may be more palatable after the birth, when the first stage of the uncertain future has been revealed. Future research should examine the role of temporality in decision-making around prenatal genomic sequencing across diverse population cohorts, in order to observe more precisely the role that structural barriers play in patient preferences.