Protocol for a Prospective, Observational Cost-effectiveness Analysis of Returning Secondary Findings of Genome Sequencing for Unexplained Suspected Genetic Conditions.

PURPOSE: Although costly, genome-wide sequencing (GWS) detects an extensive range of variants, enhancing our ability to diagnose and assess risk for an increasing number of diseases. In addition to detecting variants related to the indication for testing, GWS can detect secondary variants in BRCA1, BRCA2, and other genes for which early intervention may improve health. As the list of secondary findings grows, there is increased demand for surveillance and management by multiple specialists, adding pressure to constrained health care budgets. Secondary finding testing is actively debated because some consider it opportunistic screening for future health risks that may not manifest. Given the economic implications of secondary finding testing and follow-up and its unproven clinical utility, the objective is to assess the incremental cost-effectiveness of secondary finding ascertainment per case detected and per unit of improved clinical utility in families of children with unexplained suspected genetic conditions undergoing clinical GWS. METHODS: Those undergoing trio genome or exome sequencing are eligible for the study. Positive secondary finding index cases will be matched to negative controls (1:2) based on age group, primary result(s) type, and clinical indication. During the 2-year study, 71 cases and 142 matched controls are expected. Health service use will be collected in patients and 1 adult family member every 6 months. The per-child and per-dyad total cost will be determined by multiplying use of each resource by a corresponding unit price and summing all cost items. Costs will be estimated from the public and societal payer perspectives. The mean cost per child and per dyad for secondary finding-positive and secondary finding-negative groups will be compared statistically. If important demographic differences are observed between groups, ordinary least-squares regression, log transformation, or other nonparametric technique will be used to compare adjusted mean costs. The ratio of the difference in mean cost to the secondary finding yield will be used to estimate incremental cost-effectiveness. In secondary analyses, effectiveness will be estimated using the number of clinical management changes due to secondary findings or the Clinician-Reported Genetic Testing Utility Index (C-GUIDE) score, a validated measure of clinical utility. Sensitivity analysis will be undertaken to assess the robustness of the findings to variation in key parameters. IMPLICATIONS: This study generates key evidence to inform clinical practice and funding allocation related to secondary finding testing. The inclusion of family members and a new measure of clinical utility represent important advancements in economic evaluation in genomics.

Decision impact studies, evidence of clinical utility for genomic assays in cancer: A scoping review.

BACKGROUND: Decision impact studies have become increasingly prevalent in cancer prognostic research in recent years. These studies aim to evaluate the impact of a genomic test on decision-making and appear to be a new form of evidence of clinical utility. The objectives of this review were to identify and characterize decision impact studies in genomic medicine in cancer care and categorize the types of clinical utility outcomes reported. METHODS: We conducted a search of four databases, Medline, Embase, Scopus and Web of Science, from inception to June 2022. Empirical studies that reported a "decision impact" assessment of a genomic assay on treatment decisions or recommendations for cancer patients were included. We followed scoping review methodology and adapted the Fryback and Thornbury Model to collect and analyze data on clinical utility. The database searches identified 1803 unique articles for title/abstract screening; 269 articles moved to full-text review. RESULTS: 87 studies met inclusion criteria. All studies were published in the last 12 years with the majority for breast cancer (72%); followed by other cancers (28%) (lung, prostate, colon). Studies reported on the impact of 19 different proprietary (18) and generic (1) assays. Across all four levels of clinical utility, outcomes were reported for 22 discrete measures, including the impact on provider/team decision-making (100%), provider confidence (31%); change in treatment received (46%); patient psychological impacts (17%); and costing or savings impacts (21%). Based on the data synthesis, we created a comprehensive table of outcomes reported for clinical utility. CONCLUSIONS: This scoping review is a first step in understanding the evolution and uses of decision impact studies and their influence on the integration of emerging genomic technologies in cancer care. The results imply that DIS are positioned to provide evidence of clinical utility and impact clinical practice and reimbursement decision-making in cancer care. Systematic review registration: Open Science Framework osf.io/hm3jr.

Pharmacogenetic profiling via genome sequencing in children with medical complexity.

BACKGROUND: Children with medical complexity (CMC) are a priority pediatric population, with high resource use and associated costs. Genome-wide sequencing is increasingly organized for CMC early in life as a diagnostic test. Polypharmacy becomes common as CMC age. Clinically relevant pharmacogenetic (PGx) information can be extracted from existing genome sequencing (GS) data via GS-PGx profiling. The role of GS-PGx profiling in the CMC population is unclear. METHODS: Prescribed medications were extracted from care plans of 802 eligible CMC enrolled in a structured Complex Care Program over a 10-year period. Drug-gene associations were annotated using curated Clinical Pharmacogenetics Implementation Consortium data. GS-PGx profiling was then performed for a subset of 50 CMC. RESULTS: Overall, 546 CMC (68%) were prescribed at least one medication with an established PGx association. In the GS-PGx subgroup, 24 (48%) carried variants in pharmacogenes with drug-gene guidelines for one or more of their current medications. All had findings of potential relevance to some medications, including 32 (64%) with variants in CYP2C19 that could affect their metabolism of proton-pump inhibitors. CONCLUSION: GS-PGx profiling at the time of diagnostics-focused genetic testing could be an efficient way to incorporate precision prescribing practices into the lifelong care of CMC. IMPACT: Polypharmacy and genetic test utilization are both common in children with medical complexity. The role of repurposing genome sequencing data for pharmacogenetic profiling in children with medical complexity was previously unclear. We identified a high rate of medication use with clinically relevant drug-gene associations in this priority pediatric population and demonstrated that relevant pharmacogenetic information can be extracted from their existing genome sequencing data. Pharmacogenetic profiling at the time of diagnostics-focused genetic testing could be an efficient way to incorporate precision prescribing practices into the lifelong care of children with medical complexity.

Germline variants in tumor suppressor FBXW7 lead to impaired ubiquitination and a neurodevelopmental syndrome.

Neurodevelopmental disorders are highly heterogenous conditions resulting from abnormalities of brain architecture and/or function. FBXW7 (F-box and WD-repeat-domain-containing 7), a recognized developmental regulator and tumor suppressor, has been shown to regulate cell-cycle progression and cell growth and survival by targeting substrates including CYCLIN E1/2 and NOTCH for degradation via the ubiquitin proteasome system. We used a genotype-first approach and global data-sharing platforms to identify 35 individuals harboring de novo and inherited FBXW7 germline monoallelic chromosomal deletions and nonsense, frameshift, splice-site, and missense variants associated with a neurodevelopmental syndrome. The FBXW7 neurodevelopmental syndrome is distinguished by global developmental delay, borderline to severe intellectual disability, hypotonia, and gastrointestinal issues. Brain imaging detailed variable underlying structural abnormalities affecting the cerebellum, corpus collosum, and white matter. A crystal-structure model of FBXW7 predicted that missense variants were clustered at the substrate-binding surface of the WD40 domain and that these might reduce FBXW7 substrate binding affinity. Expression of recombinant FBXW7 missense variants in cultured cells demonstrated impaired CYCLIN E1 and CYCLIN E2 turnover. Pan-neuronal knockdown of the Drosophila ortholog, archipelago, impaired learning and neuronal function. Collectively, the data presented herein provide compelling evidence of an F-Box protein-related, phenotypically variable neurodevelopmental disorder associated with monoallelic variants in FBXW7.

Gene therapy: perspectives from young adults with Leber's congenital amaurosis.

AIMS/PURPOSE: To investigate Leber congenital amaurosis (LCA) patients' expectations, decision-making processes and gene therapy-related concerns. METHODS: Using a qualitative approach, we explored perceptions of gene therapy and clinical trials among individuals with LCA. Young adults with a clinical diagnosis of LCA were recruited through the Ocular Genetics Programme at the Hospital for Sick Children. Semi-structured interviews were conducted with ten patients and analysed following the principles of qualitative description. RESULTS: Study participants were aware of ongoing gene therapy research trials and actively sought information regarding advances in ophthalmology and vision restoration. The majority of participants would enrol or were enrolled in a gene-replacement therapy trial, while a minority was ambivalent or would not enrol if provided an opportunity. Participants attributed different values to clinical trials, which influenced their willingness to participate. Intrinsic factors related to coping, adaptation to vision loss and resilience also influenced decision-making. DISCUSSION: This study highlights the complex factors involved in gene-therapy-related decision-making and acts as a proponent for adopting patient-centred care strategies when counselling individuals considering gene therapy or clinical trial participation.

Cascade health service use in family members following genetic testing in children: a scoping literature review.

Cascade genetic testing is the identification of individuals at risk for a hereditary condition by genetic testing in relatives of people known to possess particular genetic variants. Cascade testing has health system implications, however cascade costs and health effects are not considered in health technology assessments (HTAs) that focus on costs and health consequences in individual patients. Cascade health service use must be better understood to be incorporated in HTA of emerging genetic tests for children. The purpose of this review was to characterise published research related to patterns and costs of cascade health service use by relatives of children with any condition diagnosed through genetic testing. To this end, a scoping literature review was conducted. Citation databases were searched for English-language papers reporting uptake, costs, downstream health service use, or cost-effectiveness of cascade investigations of relatives of children who receive a genetic diagnosis. Included publications were critically appraised, and findings were synthesised. Twenty publications were included. Sixteen had a paediatric proband population; four had a combined paediatric and adult proband population. Uptake of cascade testing varied across diseases, from 37% for cystic fibrosis, 39% to 65% for hypertrophic cardiomyopathy, and 90% for rare monogenic conditions. Two studies evaluated costs. It was concluded that cascade testing in the child-to-parent direction has been reported in a variety of diseases, and that understanding the scope of cascade testing will aid in the design and conduct of HTA of emerging genetic technologies to better inform funding and policy decisions.

Primary care providers' role in newborn screening result notification for cystic fibrosis.

OBJECTIVE: To explore primary care providers' (PCPs') role in result notification for newborn screening (NBS) for cystic fibrosis (CF), given that expanded NBS has increased the number of positive screening test results, drawing attention to the role of PCPs in supporting families. DESIGN: Cross-sectional survey and qualitative interviews. SETTING: Ontario. PARTICIPANTS: Primary care providers (FPs, pediatricians, and midwives) who received a positive CF NBS result for an infant in their practice in the 6 months before the study. MAIN OUTCOME MEASURES: Whether the PCP notified the family of the initial positive CF screening result. RESULTS: Data from 321 PCP surveys (response rate of 51%) are reported, including 208 FPs, 68 pediatricians, and 45 midwives. Interviews were completed with 34 PCPs. Most (65%) surveyed PCPs reported notifying the infant's family of the initial positive screening result; 81% agreed that they have an important role to play in NBS; and 88% said it was important for PCPs, rather than the NBS centre, to notify families of initial positive results. With support and information from NBS centres, 68% would be extremely or very confident in doing so; this dropped to 54% when reflecting on their recent reporting experience. More than half (58%) of all PCPs said written point-of-care information from the NBS centre was the most helpful format. Adjusted for relevant factors, written educational information was associated with a lower rate of notifying families than written plus verbal information (risk ratio of 0.79; 95% CI 0.69 to 0.92). In the interviews, PCPs emphasized the challenge of balancing required content knowledge with the desire for the news to come from a familiar provider. CONCLUSION: Most PCPs notify families of NBS results and value this role. These data are relevant as NBS programs and other genomic services expand and consider ways of keeping PCPs confident and actively involved.

Newborn screening for cystic fibrosis: Role of primary care providers in caring for infants with positive screening results.

OBJECTIVE: To explore primary care providers' (PCPs') preferred roles and confidence in caring for infants receiving a positive cystic fibrosis (CF) newborn screening (NBS) result, as well as management of CF family planning issues, given that expanded NBS has resulted in an increase in positive results. DESIGN: Mailed questionnaire. SETTING: Ontario. PARTICIPANTS: Ontario FPs, pediatricians, and midwives identified by Newborn Screening Ontario as having had an infant with a positive CF NBS result in their practice in the previous 6 months. MAIN OUTCOME MEASURE: Primary care providers' preferred roles in providing well-baby care for infants with positive CF screening results. RESULTS: Overall, 321 of 628 (51%) completed surveys (208 FPs, 68 pediatricians, 45 midwives). For well-baby care for infants confirmed to have CF, 77% of PCPs indicated they would not provide total care (ie, 68% would share care with other specialists and 9% would refer to specialists completely); for infants with an inconclusive CF diagnosis, 50% of PCPs would provide total care, 45% would provide shared care, and 5% would refer to a specialist; for CF carriers, 89% of PCPs would provide total care, 9% would provide shared care, and 2% would refer. Half (54%) of PCPs were extremely or very confident in providing reassurance about CF carriers' health. Only 25% knew how to order parents' CF carrier testing; 67% knew how to refer for prenatal diagnosis. Confidence in reassuring parents about the health of CF carrier children was associated with providing total well-baby care for CF carriers (risk ratio of 1.50; 95% CI 1.14 to 1.97) and infants with an inconclusive diagnosis (risk ratio of 3.30; 95% CI 1.34 to 8.16). CONCLUSION: Most PCPs indicated willingness to treat infants with a range of CF NBS results in some capacity. It is concerning that some indicated CF carriers should have specialist involvement and only half were extremely or very confident about reassuring families about carrier status. This raises issues about possible medicalization of those with carrier status, prompting the need for PCP education about genetic disorders and the meaning of genetic test results.

Expanding Clinical Presentations Due to Variations in THOC2 mRNA Nuclear Export Factor.

Multiple TREX mRNA export complex subunits (e.g., THOC1, THOC2, THOC5, THOC6, THOC7) have now been implicated in neurodevelopmental disorders (NDDs), neurodegeneration and cancer. We previously implicated missense and splicing-defective THOC2 variants in NDDs and a broad range of other clinical features. Here we report 10 individuals from nine families with rare missense THOC2 variants including the first case of a recurrent variant (p.Arg77Cys), and an additional individual with an intragenic THOC2 microdeletion (Del-Ex37-38). Ex vivo missense variant testing and patient-derived cell line data from current and published studies show 9 of the 14 missense THOC2 variants result in reduced protein stability. The splicing-defective and deletion variants result in a loss of small regions of the C-terminal THOC2 RNA binding domain (RBD). Interestingly, reduced stability of THOC2 variant proteins has a flow-on effect on the stability of the multi-protein TREX complex; specifically on the other NDD-associated THOC subunits. Our current, expanded cohort refines the core phenotype of THOC2 NDDs to language disorder and/or ID, with a variable severity, and disorders of growth. A subset of affected individuals' has severe-profound ID, persistent hypotonia and respiratory abnormalities. Further investigations to elucidate the pathophysiological basis for this severe phenotype are warranted.

De novo missense variants in RAC3 cause a novel neurodevelopmental syndrome.

PURPOSE: RAC3 is an underexamined member of the Rho GTPase gene family that is expressed in the developing brain and linked to key cellular functions. De novo missense variants in the homolog RAC1 were recently associated with developmental disorders. In the RAC subfamily, transforming missense changes at certain shared residues have been observed in human cancers and previously characterized in experimental studies. The purpose of this study was to determine whether constitutional dysregulation of RAC3 is associated with human disease. METHODS: We discovered a RAC3 variant in the index case using genome sequencing, and searched for additional variants using international data-sharing initiatives. Functional effects of the variants were assessed using a multifaceted approach generalizable to most clinical laboratory settings. RESULTS: We rapidly identified five individuals with de novo monoallelic missense variants in RAC3, including one recurrent change. Every participant had severe intellectual disability and brain malformations. In silico protein modeling, and prior in vivo and in situ experiments, supported a transforming effect for each of the three different RAC3 variants. All variants were observed in databases of somatic variation in cancer. CONCLUSIONS: Missense variants in RAC3 cause a novel brain disorder, likely through a mechanism of constitutive protein activation.

False-Positive Newborn Screening for Cystic Fibrosis and Health Care Use.

OBJECTIVES: Evidence is mixed regarding the impact of false-positive (FP) newborn bloodspot screening (NBS) results on health care use. Using cystic fibrosis (CF) as an example, we determined the association of FP NBS results with health care use in infants and their mothers in Ontario, Canada. METHODS: We conducted a population-based cohort study of all infants with FP CF results (N = 1564) and screen-negative matched controls (N = 6256) born between April 2008 and November 2012 using linked health administrative data. Outcomes included maternal and infant physician and emergency visits and inpatient hospitalizations from the infant's third to 15th month of age. Negative binomial regression tested associations of NBS status with outcomes, adjusting for infant and maternal characteristics. RESULTS: A greater proportion of infants with FP results had >2 outpatient visits (16.2% vs 13.2%) and >2 hospital admissions (1.5% vs 0.7%) compared with controls; CF-related admissions and emergency department visits were not different from controls. Differences persisted after adjustment, with higher rates of outpatient visits (relative risk 1.39; 95% confidence interval 1.20-1.60) and hospital admissions (relative risk 1.67; 95% confidence interval 1.21-2.31) for FP infants. Stratified models indicated the effect of FP status was greater among those whose primary care provider was a pediatrician. No differences in health care use among mothers were detected. CONCLUSIONS: Higher use of outpatient services among FP infants may relate to a lengthy confirmatory testing process or follow-up carrier testing. However, increased rates of hospitalization might signal heightened perceptions of vulnerability among healthy infants.

Psychosocial Response to Uncertain Newborn Screening Results for Cystic Fibrosis.

OBJECTIVE: To explore the psychosocial implications of diagnostic uncertainty that result from inconclusive results generated by newborn bloodspot screening (NBS) for cystic fibrosis (CF). STUDY DESIGN: Using a mixed methods prospective cohort study of children who received NBS for CF, we compared psychosocial outcomes of parents whose children who received persistently inconclusive results with those whose children received true positive or screen-negative results. RESULTS: Mothers of infants who received inconclusive results (n = 17), diagnoses of CF (n = 15), and screen-negative results (n = 411) were surveyed; 23 parent interviews were completed. Compared with mothers of infants with true positive/screen-negative results, mothers of infants with inconclusive results reported greater perceived uncertainty (P < .006) but no differences in anxiety or vulnerability (P > .05). Qualitatively, parents valued being connected to experts but struggled with the meaning of an uncertain diagnosis, worried about their infant's health-related vulnerability, and had mixed views about surveillance. CONCLUSION: Inconclusive CF NBS results were not associated with anxiety or vulnerability but led to health-related uncertainty and qualitative concerns. Findings should be considered alongside efforts to optimize protocols for CF screening and surveillance. Educational and psychosocial supports are warranted for these families.

A secondary benefit: the reproductive impact of carrier results from newborn screening for cystic fibrosis.

PURPOSE: Newborn screening (NBS) for cystic fibrosis (CF) can identify carriers, which is considered a benefit that enables reproductive planning. We examined the reproductive impact of carrier result disclosure of NBS for CF. METHODS: We surveyed mothers of carrier infants after NBS (Time 1) and 1 year later (Time 2) to ascertain intended and reported communication of their infants' carrier results to relatives, carrier testing for themselves/other children, and reproductive decisions. A sub-sample of mothers was also interviewed at Time 1 and Time 2. RESULTS: The response rate was 54%. A little more than half (55%) of mothers underwent carrier testing at Time 1; another 40% of those who intended to undergo testing at Time 1 underwent testing at Time 2. Carrier result communication to relatives was high (92%), but a majority of participants did not expect the results to influence family planning (65%). All interviewed mothers valued learning their infants' carrier results. Some underwent carrier testing and then shared results with family. Others did not use the results or used them in unintended ways. CONCLUSION: Although mothers valued learning carrier results from NBS, they reported moderate uptake of carrier testing and limited influence on family planning. Our study highlights the secondary nature of the benefit of disclosing carrier results of NBS.Genet Med 19 4, 403-411.

Parent Experience With False-Positive Newborn Screening Results for Cystic Fibrosis.

BACKGROUND: The risk of psychosocial harm in families of infants with false-positive (FP) newborn bloodspot screening (NBS) results for cystic fibrosis (CF) is a longstanding concern. Whether well designed retrieval and confirmatory testing systems can mitigate risks remains unknown. METHODS: Using a mixed-methods cohort design, we obtained prospective self-report data from mothers of infants with FP CF NBS results 2 to 3 months after confirmatory testing at Ontario's largest follow-up center, and from a randomly selected control sample of mothers of screen negative infants from the same region. Mothers completed a questionnaire assessing experience and psychosocial response. A sample of mothers of FP infants completed qualitative interviews. RESULTS: One hundred thirty-four mothers of FP infants (response rate, 55%) and 411 controls (response rate, 47%) completed questionnaires; 54 mothers of FP infants were interviewed. Selected psychosocial response measures did not detect psychosocial distress in newborns or 1 year later (P > .05). Mothers recalled distress during notification of the positive result and in the follow-up testing period related to fear of chronic illness, but valued the screening system of care in mitigating concerns. CONCLUSIONS: Although immediate distress was reported among mothers of FP infants, selected psychometric tools did not detect these concerns. The NBS center from which mothers were recruited minimizes delay between notification and confirmatory testing and ensures trained professionals are communicating results and facilitating follow-up. These factors may explain the presence of minimal psychosocial burden. The screening system reflected herein may be a model for NBS programs working to minimize FP-related psychosocial harm.

Testing personalized medicine: patient and physician expectations of next-generation genomic sequencing in late-stage cancer care.

Developments in genomics, including next-generation sequencing technologies, are expected to enable a more personalized approach to clinical care, with improved risk stratification and treatment selection. In oncology, personalized medicine is particularly advanced and increasingly used to identify oncogenic variants in tumor tissue that predict responsiveness to specific drugs. Yet, the translational research needed to validate these technologies will be conducted in patients with late-stage cancer and is expected to produce results of variable clinical significance and incidentally identify genetic risks. To explore the experiential context in which much of personalized cancer care will be developed and evaluated, we conducted a qualitative interview study alongside a pilot feasibility study of targeted DNA sequencing of metastatic tumor biopsies in adult patients with advanced solid malignancies. We recruited 29/73 patients and 14/17 physicians; transcripts from semi-structured interviews were analyzed for thematic patterns using an interpretive descriptive approach. Patient hopes of benefit from research participation were enhanced by the promise of novel and targeted treatment but challenged by non-findings or by limited access to relevant trials. Family obligations informed a willingness to receive genetic information, which was perceived as burdensome given disease stage or as inconsequential given faced challenges. Physicians were optimistic about long-term potential but conservative about immediate benefits and mindful of elevated patient expectations; consent and counseling processes were expected to mitigate challenges from incidental findings. These findings suggest the need for information and decision tools to support physicians in communicating realistic prospects of benefit, and for cautious approaches to the generation of incidental genetic information.