Preconception Carrier Screening by Genome Sequencing: Results from the Clinical Laboratory.

Advances in sequencing technologies permit the analysis of a larger selection of genes for preconception carrier screening. The study was designed as a sequential carrier screen using genome sequencing to analyze 728 gene-disorder pairs for carrier and medically actionable conditions in 131 women and their partners (n = 71) who were planning a pregnancy. We report here on the clinical laboratory results from this expanded carrier screening program. Variants were filtered and classified using the latest American College of Medical Genetics and Genomics (ACMG) guideline; only pathogenic and likely pathogenic variants were confirmed by orthologous methods before being reported. Novel missense variants were classified as variants of uncertain significance. We reported 304 variants in 202 participants. Twelve carrier couples (12/71 couples tested) were identified for common conditions; eight were carriers for hereditary hemochromatosis. Although both known and novel variants were reported, 48% of all reported variants were missense. For novel splice-site variants, RNA-splicing assays were performed to aid in classification. We reported ten copy-number variants and five variants in non-coding regions. One novel variant was reported in F8, associated with hemophilia A; prenatal testing showed that the male fetus harbored this variant and the neonate suffered a life-threatening hemorrhage which was anticipated and appropriately managed. Moreover, 3% of participants had variants that were medically actionable. Compared with targeted mutation screening, genome sequencing improves the sensitivity of detecting clinically significant variants. While certain novel variant interpretation remains challenging, the ACMG guidelines are useful to classify variants in a healthy population.

Time Costs for Genetic Counseling in Preconception Carrier Screening with Genome Sequencing.

Advances in technology and the promise of personalized health care are driving greater use of genome sequencing (GS) for a variety of clinical scenarios. As health systems consider adopting GS, they need to understand the impact of GS on the organization and cost of care. While research has documented a dramatic decrease in the cost of sequencing and interpreting GS, few studies have examined how GS impacts genetic counseling workloads. This study examined the time needed to provide genetic counseling for GS in the context of preconception carrier screening. Genetic counselors prospectively reported on the time spent in the results disclosure process with 107 study participants who were part of the NextGen study. We found that the median time for results disclosure was 64 min (ranged from 5 to 229 min). Preparation work was the most time-consuming activity. Qualitative data from journal entries, debrief interviews with genetic counselors, and detailed case conference notes provided information on factors influencing time for results disclosure and implications for practice. Results suggest that expanded carrier screening could require significant increases in genetic counseling time, unless we are able to generate new resources to reduce preparation work or develop other strategies such as the creation of new models to deliver this type of service.

Genome sequencing and carrier testing: decisions on categorization and whether to disclose results of carrier testing.

PURPOSE: We investigated the use of genome sequencing for preconception carrier testing. Genome sequencing could identify one or more of thousands of X-linked or autosomal recessive conditions that could be disclosed during preconception or prenatal counseling. Therefore, a framework that helps both clinicians and patients understand the possible range of findings is needed to respect patient preferences by ensuring that information about only the desired types of genetic conditions are provided to a given patient. METHODS: We categorized gene-condition pairs into groups using a previously developed taxonomy of genetic conditions. Patients could elect to receive results from these categories. A Return of Results Committee (RORC) developed inclusion and exclusion criteria for each category. RESULTS: To date, the RORC has categorized 728 gene-condition pairs: 177 are categorized as life span-limiting, 406 are categorized as serious, 93 are categorized as mild, 41 are categorized as unpredictable, and 11 are categorized as adult-onset. An additional 64 gene-condition pairs were excluded from reporting to patients or put on a watch list, generally because evidence that a gene and condition were associated was limited. CONCLUSION: Categorization of gene-condition pairs using our taxonomy simplifies communication regarding patient preferences for carrier information from a genomic test.Genet Med advance online publication 12 January 2017.

Reasons for Declining Preconception Expanded Carrier Screening Using Genome Sequencing.

Genomic carrier screening can identify more disease-associated variants than existing carrier screening methodologies, but its utility from patients' perspective is not yet established. A randomized controlled trial for preconception genomic carrier screening provided an opportunity to understand patients' decisions about whether to accept or decline testing. We administered a survey to potential genomic carrier screening recipients who declined participation (N = 240) to evaluate their reasons for doing so. Two thirds of women declined participation. We identified major themes describing reasons these individuals declined to participate; the most common were time limitation, lack of interest, not wanting to know the information, and potential cause of worry or anxiety. Most women eligible for genomic carrier screening indicated that their reasons for opting out were due to logistical issues rather than opposing the rationale for testing. As expanded carrier screening and genomic sequencing become a more routine part of clinical care, it is anticipated there will be variable uptake from individuals for this testing. Thus, the advancement of clinical carrier screening from single genes, to expanded screening panels, to an exome- or genome-wide platform, will require approaches that respect individual choice to receive genetic testing for reproductive risk assessment.

Patients' ratings of genetic conditions validate a taxonomy to simplify decisions about preconception carrier screening via genome sequencing.

Advances in genome sequencing and gene discovery have created opportunities to efficiently assess more genetic conditions than ever before. Given the large number of conditions that can be screened, the implementation of expanded carrier screening using genome sequencing will require practical methods of simplifying decisions about the conditions for which patients want to be screened. One method to simplify decision making is to generate a taxonomy based on expert judgment. However, expert perceptions of condition attributes used to classify these conditions may differ from those used by patients. To understand whether expert and patient perceptions differ, we asked women who had received preconception genetic carrier screening in the last 3 years to fill out a survey to rate the attributes (predictability, controllability, visibility, and severity) of several autosomal recessive or X-linked genetic conditions. These conditions were classified into one of five taxonomy categories developed by subject experts (significantly shortened lifespan, serious medical problems, mild medical problems, unpredictable medical outcomes, and adult-onset conditions). A total of 193 women provided 739 usable ratings across 20 conditions. The mean ratings and correlations demonstrated that participants made distinctions across both attributes and categories. Aggregated mean attribute ratings across categories demonstrated logical consistency between the key features of each attribute and category, although participants perceived little difference between the mild and serious categories. This study provides empirical evidence for the validity of our proposed taxonomy, which will simplify patient decisions for results they would like to receive from preconception carrier screening via genome sequencing.

Genotype-phenotype characterization in 13 individuals with chromosome Xp11.22 duplications.

We report 13 new individuals with duplications in Xp11.22-p11.23. The index family has one male and two female members in three generations with mild-severe intellectual disability (ID), speech delay, dysmorphic features, early puberty, constipation, and/or hand and foot abnormalities. Affected individuals were found to have two small duplications in Xp11.22 at nucleotide position (hg19) 50,112,063-50,456,458 bp (distal) and 53,160,114-53,713,154 bp (proximal). Collectively, these two regions include 14 RefSeq genes, prompting collection of a larger cohort of patients, in an attempt to delineate critical genes associated with the observed phenotype. In total, we have collected data on nine individuals with duplications overlapping the distal duplication region containing SHROOM4 and DGKK and eight individuals overlapping the proximal region including HUWE1. Duplications of HUWE1 have been previously associated with non-syndromic ID. Our data, with previously published reports, suggest that duplications involving SHROOM4 and DGKK may represent a new syndromic X-linked ID critical region associated with mild to severe ID, speech delay +/- dysarthria, attention deficit disorder, precocious puberty, constipation, and motor delay. We frequently observed foot abnormalities, 5th finger clinodactyly, tapering fingers, constipation, and exercise intolerance in patients with duplications of these two genes. Regarding duplications including the proximal region, our observations agree with previous studies, which have found associations with intellectual disability. In addition, expressive language delay, failure to thrive, motor delay, and 5th finger clinodactyly were also frequently observed in patients with the proximal duplication.

Generating a taxonomy for genetic conditions relevant to reproductive planning.

As genome or exome sequencing (hereafter genome-scale sequencing) becomes more integrated into standard care, carrier testing is an important possible application. Carrier testing using genome-scale sequencing can identify a large number of conditions, but choosing which conditions/genes to evaluate as well as which results to disclose can be complicated. Carrier testing generally occurs in the context of reproductive decision-making and involves patient values in a way that other types of genetic testing may not. The Kaiser Permanente Clinical Sequencing Exploratory Research program is conducting a randomized clinical trial of preconception carrier testing that allows participants to select their preferences for results from among broad descriptive categories rather than selecting individual conditions. This paper describes (1) the criteria developed by the research team, the return of results committee (RORC), and stakeholders for defining the categories; (2) the process of refining the categories based on input from patient focus groups and validation through a patient survey; and (3) how the RORC then assigned specific gene-condition pairs to taxonomy categories being piloted in the trial. The development of four categories (serious, moderate/mild, unpredictable, late onset) for sharing results allows patients to select results based on their values without separately deciding their interest in knowing their carrier status for hundreds of conditions. A fifth category, lifespan limiting, was always shared. The lessons learned may be applicable in other results disclosure situations, such as incidental findings.

"Is It Worth Knowing?" Focus Group Participants' Perceived Utility of Genomic Preconception Carrier Screening.

As genome sequencing technology advances, research is needed to guide decision-making about what results can or should be offered to patients in different clinical settings. We conducted three focus groups with individuals who had prior preconception genetic testing experience to explore perceived advantages and disadvantages of genome sequencing for preconception carrier screening, compared to usual care. Using a discussion guide, a trained qualitative moderator facilitated the audio-recorded focus groups. Sixteen individuals participated. Thematic analysis of transcripts started with a grounded approach and subsequently focused on participants' perceptions of the value of genetic information. Analysis uncovered two orientations toward genomic preconception carrier screening: "certain" individuals desiring all possible screening information; and "hesitant" individuals who were more cautious about its value. Participants revealed valuable information about barriers to screening: fear/anxiety about results; concerns about the method of returning results; concerns about screening necessity; and concerns about partner participation. All participants recommended offering choice to patients to enhance the value of screening and reduce barriers. Overall, two groups of likely users of genome sequencing for preconception carrier screening demonstrated different perceptions of the advantages or disadvantages of screening, suggesting tailored approaches to education, consent, and counseling may be warranted with each group.

Impact of expanded carrier screening on health care utilization.

OBJECTIVES: To evaluate potential consequences of expanded carrier screening (ECS) for reproductive risk on health care utilization among women who are not at increased reproductive risk. STUDY DESIGN: Women planning pregnancy were randomized to usual care carrier screening or ECS to assess reproductive risks. Electronic health record (EHR) data were used to evaluate the effects of ECS on pregnancy-related utilization and general health care utilization among all study participants who did not receive positive ECS results of at least a 25% risk (ie, received negative [normal] ECS results). METHODS: EHR data were extracted through research-ready databases and extensive chart review for 304 participants. We analyzed the effect of ECS for women who were not found to be at increased reproductive risk on (1) utilization of mental health services in the period between randomization and initial results disclosure; (2) utilization of general outpatient and inpatient services, specialty services, and mental health-related services in the year following randomization; and (3) utilization and refusal of pregnancy-related services among pregnant women (n = 129) prior to and following randomization. RESULTS: No significant differences in health care utilization were found between women randomized to receive ECS and those receiving usual care. Women who received negative ECS results did not refuse recommended screening for conditions that are not identified via ECS at a higher rate than women in the usual care arm. CONCLUSIONS: These results suggest that ECS does not have unintended negative impacts on the health care system for the majority of patients who are not at increased reproductive risk.

Lessons Learned From A Study Of Genomics-Based Carrier Screening For Reproductive Decision Making.

Genomics-based carrier screening is one of many opportunities to use genomic information to inform medical decision making, but clinicians, health care delivery systems, and payers need to determine whether to offer screening and how to do so in an efficient, ethical way. To shed light on this issue, we conducted a study in the period 2014-17 to inform the design of clinical screening programs and guide further health services research. Many of our results have been published elsewhere; this article summarizes the lessons we learned from that study and offers policy insights. Our experience can inform understanding of the potential impact of expanded carrier screening services on health system workflows and workforces-impacts that depend on the details of the screening approach. We found limited patient or health system harms from expanded screening. We also found that some patients valued the information they learned from the process. Future policy discussions should consider the value of offering such expanded carrier screening in health delivery systems with limited resources.

The NextGen Study: patient motivation for participation in genome sequencing for carrier status.

BACKGROUND: While translational genomic sequencing research is increasing, few studies have been limited to healthy individuals; most have focused on patients with a disease or a strong family history of a disorder. The limited studies that have included healthy individuals have focused on the disclosure of medically actionable secondary results, rather than carrier status, to assess reproductive risks. To address this important gap, we conducted the NextGen study, which focuses on carrier status and medically actionable secondary findings in a population of women planning a pregnancy. METHODS: We assessed 310 participants' motivations for receiving genome sequencing for expanded carrier screening and experiences with familial genetic conditions that may relate to study participation. RESULTS: Most participants reported that obtaining general health information from genome sequencing was their primary motivator, even though they were recruited to join a study to learn more about carrier status. Forty-two percent of enrolled women became pregnant prior to obtaining sequencing results. CONCLUSION: Genomic carrier testing may need to be offered to women prior to active pregnancy efforts to be useful for reproductive planning.

Illustrative case studies in the return of exome and genome sequencing results.

Whole genome and exome sequencing tests are increasingly being ordered in clinical practice, creating a need for research exploring the return of results from these tests. A goal of the Clinical Sequencing and Exploratory Research (CSER) consortium is to gain experience with this process to develop best practice recommendations for offering exome and genome testing and returning results. Genetic counselors in the CSER consortium have an integral role in the return of results from these genomic sequencing tests and have gained valuable insight. We present seven emerging themes related to return of exome and genome sequencing results accompanied by case descriptions illustrating important lessons learned, counseling challenges specific to these tests and considerations for future research and practice.