Expanded carrier screening panels-does bigger mean better?

Cost-effectiveness of population-based expanded reproductive carrier screening for genetic diseases in Australia: a microsimulation analysis

Using the Australian Census survey 2021 as base population, a microsimulation model, PreconMOD was developed to evaluate the cost-effectiveness of population-based expanded reproductive carrier screening (RCS) for 569 recessive conditions from the health service and societal perspectives. The model simulated the effect of expanded RCS including the downstream interventions for at-risk couples on cost and outcomes. The comparators were (i) no population screening (ii) limited screening for cystic fibrosis, spinal muscular atrophy, and fragile X syndrome and (iii) a 300 conditions screening panel. Averted affected births and health service cost with expanded RCS were projected to year 2061. At a 50% uptake, our model predicts that expanded RCS is cost saving (i.e., higher quality-adjusted life-years and lower costs) compared with other screening strategies in the model from the health service and societal perspectives. The number of affected births averted in a single cohort would increase from 84 [95% confidence interval (CI) 60-116] with limited screening to 2067 (95%CI 1808-2376) with expanded RCS. Expanded RCS was cost-saving compared to the 300-conditions screening panel. Indirect cost accounted for about one-third of the total costs associated with recessive disorders. Our model predicts that the direct treatment cost associated with current limited 3 genes screening would increase by 20% each year to A$73.4 billion to the health system by 2061. Our findings contribute insights on the cost burden of genetic diseases and the economic benefits of expanded RCS to better informed resource allocation decisions.

The potential impact of implementation of expanded carrier screening on pediatric patient diagnoses: A retrospective chart review of patients who receive care in an outpatient genetics clinic in the northeast

The use of expanded carrier screening (ECS) to assess reproductive risk for autosomal recessive (AR) or X-linked recessive (XLR) conditions has been increasingly integrated into obstetrical care. The aim of this study was to determine what proportion of pediatric patients seen by a medical genetics practice could have had their diagnosis predicted if the parent(s) had undergone currently available ECS at the time of data collection in 2021. A retrospective chart review of patients seen for a medical genetic evaluation at a large academic institution was performed from June 1, 2017, through June 1, 2020. At this institution, 8% of patients were diagnosed with an AR or XLR condition. Of these patients, 61% of the diagnoses could have been predicted in advance if the parent(s) had undergone ECS via the panel referenced in this study. The results of this study highlight the broad range of conditions currently seen in a clinical setting that could be identified as a risk prior to or during pregnancy via ECS. In the prenatal setting, ascertainment of reproductive risk via ECS enables prospective parents to undertake interventions such as prenatal and preimplantation genetic diagnosis. For parents who decline reproductive risk-reducing measures, knowledge about neonatal risk allows for prompt confirmatory testing. In the pediatric setting, the option of early and focused testing can benefit affected individuals and their families.

Clinical application value of pre-pregnancy carrier screening in Chinese Han childbearing population

BACKGROUND

To explore the clinical application value of pre-conception expanded carrier screening (PECS) in the Chinese Han ethnicity population of childbearing age.

METHODS

The results of genetic testing of infertile parents who underwent PECS in the Reproductive Medicine Center of the Second Affiliated Hospital of Zhengzhou University, China, from September 2019 to December 2021, were retrospectively analyzed. The carrier rate of single gene disease, the detection rate of high-risk parents, and the clinical outcome of high-risk parents were statistically analyzed.

RESULTS

A total of 1372 Chinese Han ethnicity patients underwent PECS, among which 458 patients underwent the extended 108-gene test, their overall carrier rate was 31.7%, and the detection rate of high-risk parents was 0.3%. The highest carrier rates were SLC22A (2.4%), ATP7B (2.4%), MMACHC (2.2%), PAH (1.8%), GALC (1.8%), MLC1 (1.3%), UNC13D (1.1%), CAPN3 (1.1%), and PKHD1 (1.1%). There were 488 women with fragile X syndrome-FMR1 gene detection, and 6 patients (1.2%) had FMR1 gene mutation. A total of 426 patients were screened for spinal muscular atrophy-SMN1, and the carrier rate was 3.5%, and the detection rate of parents' co-carrier was 0.5%.

CONCLUSION

Monogenic recessive hereditary diseases had a high carrier rate in the population. Pre-pregnancy screening could provide good prenatal and postnatal care guidance for patients and preimplantation genetic testing for monogenic/single gene disorders (PGT-M) and prenatal diagnosis could provide more precise reproductive choices for high-risk parents.

Before Is Better: Innovative Multidisciplinary Preconception Care in Different Clinical Contexts

CONTEXT

Implementation of pre-conception care units is still very limited in Italy. Nowadays, the population's awareness of the reproductive risks that can be reduced or prevented is very low. Purpose and main findings: We presented a new personalized multidisciplinary model of preconception care aimed at identifying and possibly reducing adverse reproductive events. We analyzed three cohorts of population: couples from the general population, infertile or subfertile couples, and couples with a previous history of adverse reproductive events. The proposal involves a deep investigation regarding family history, the personal histories of both partners, and reproductive history.

PRINCIPAL CONCLUSIONS

Preconception care is still neglected in Italy and under-evaluated by clinicians involved in natural or in vitro reproduction. Adequate preconception counseling will improve maternal and fetal obstetrical outcomes.

A capillary electrophoresis-based multiplex PCR assay for expanded carrier screening in the eastern Han Chinese population

Expanded carrier screening, a type of reproductive genetic testing for couples, has gained tremendous popularity for assessing the risk of passing on certain genetic conditions to offspring. Here, a carrier screening assay for 448 pathogenic variants was developed using capillary electrophoresis-based multiplex PCR technology. The capillary electrophoresis-based multiplex PCR assay achieved a sensitivity, specificity, and accuracy of 97.4%, 100%, and 99.6%, respectively, in detecting the specific variants. Among the 1915 couples (3830 individuals), 708 individuals (18.5%) were identified as carriers for at least one condition. Of the 708 carriers, 633 (89.4%) were heterozygous for one condition, 71 (10.0%) for two disorders, 3 (0.4%) for three disorders, and 1 (0.1%) for four disorders. Meanwhile, 30 (1.57%) couples were identified as at‐risk couples. This study describes an inexpensive and effective method for expanded carrier screening. The simplicity and accuracy of this approach will facilitate the clinical implementation of expanded carrier screening.

Utility of expanded carrier screening in pregnancies with ultrasound abnormalities

OBJECTIVE

Explore the utility of expanded carrier screening in evaluating heritable causes of congenital anomalies detected by prenatal ultrasound.

METHOD

A retrospective chart review was conducted to collect structural abnormality and genetic testing data on infants who were evaluated postnatally by a medical geneticist. These were used to determine if expanded carrier screening could have determined the etiology prior to delivery. Additionally, recessive and X-linked conditions on clinically available carrier screening panels were evaluated to determine the number of conditions associated with abnormal ultrasound findings.

RESULTS

Our retrospective chart review found 222 patients with genetic etiologies, including eight unique autosomal recessive conditions and six X-linked conditions in the 23% who underwent exome sequencing. Of these 14 unique conditions detected, three were included on a list of 271 conditions for which screening was available in 2019 and five were included on a 500 condition panel available in 2020. A literature review was performed on the list of 271 conditions and 88 were reported to be associated with one or more ultrasound abnormalities.

CONCLUSION

This study demonstrates limited but potential utility for expanded carrier screening to determine the underlying etiology of congenital anomalies.

Ethical considerations in gene selection for reproductive carrier screening

Genetic carrier screening for reproductive purposes has existed for half a century. It was originally offered to particular ethnic groups with a higher prevalence of certain severe recessive or X-linked genetic conditions, or (as carrier testing) to those with a family history of a particular genetic condition. Commercial providers are increasingly offering carrier screening on a user-pays basis. Some countries are also trialing or offering public reproductive genetic carrier screening with whole populations, rather than only to those known to have a higher chance of having a child with an inherited genetic condition. Such programs broaden the ethical and practical challenges that arise in clinical carrier testing. In this paper we consider three aspects of selecting genes for population reproductive genetic carrier screening panels that give rise to important ethical considerations: severity, variable penetrance and expressivity, and scalability; we also draw on three exemplar genes to illustrate the ethical issues raised: CFTR, GALT and SERPINA1. We argue that such issues are important to attend to at the point of gene selection for RGCS. These factors warrant a cautious approach to screening panel design, one that takes into account the likely value of the information generated by screening and the feasibility of implementation in large and diverse populations. Given the highly complex and uncertain nature of some genetic variants, careful consideration needs to be given to the balance between delivering potentially burdensome or harmful information, and providing valuable information to inform reproductive decisions.

Variants of SERPINA1 and the increasing complexity of testing for alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin deficiency (AATD) is caused by mutations in the SERPINA1 gene, which encodes the alpha-1 antitrypsin (AAT) protein. Currently, over 200 SERPINA1 variants have been identified, many of which cause the quantitative and/or qualitative changes in AAT responsible for AATD-associated lung and liver disease. The types of these pathogenic mutations are varied, often resulting in misfolding, or truncating of the AAT amino acid sequence, and improvements in sequencing technology are helping to identify known and novel genetic variants. However, due to the diversity and novelty of rare variants, the clinical significance of many is largely unknown. There is, therefore, a lack of guidance on how patients should be monitored and treated when the clinical significance of their variant combination is unclear or variable. Nevertheless, it is important that physicians understand the advantages and disadvantages of the different testing methodologies available to diagnose AATD. Owing to the autosomal inheritance of the genetic mutations responsible for AATD, genetic testing should be offered not only to patients at increased AATD risk (e.g. patients with chronic obstructive pulmonary disease), but also to relatives of those with an abnormal result. Genetic counseling may help patients and family members understand the possible outcomes of testing and the implications for the family. While stress/anxiety can arise from genetic diagnosis or confirmation of carrier status, there can be positive consequences to genetic testing, including improved lifestyle choices, directed medical care, and empowered family planning. As genetic testing technology grows and becomes more popular, testing without physician referral is becoming more prevalent, irrespective of the availability of genetic counseling. Therefore, the Alpha-1 Foundation offers genetic counseling, as well as other support and educational material, for patients with AATD, as well as their families and physicians, to help improve the understanding of potential benefits and consequences of genetic testing.

Cases in Precision Medicine: Genetic Testing to Predict Future Risk for Disease in a Healthy Patient

Genetic testing is performed more routinely in clinical practice, and direct-to-consumer tests are widely available. It has obvious appeal as a preventive health measure. Clinicians and their healthy patients increasingly inquire about genetic testing as a tool for predicting diseases, such as cancer, heart disease, or dementia. Despite demonstrated utility for diagnosis in the setting of many diseases, genetic testing still has many limitations as a predictive tool for healthy persons. This article uses a hypothetical case to review key considerations for predictive genetic testing.

Clinical Implementation of Expanded Carrier Screening in Pregnant Women at Early Gestational Weeks: A Chinese Cohort Study

Demands for expanded carrier screening (ECS) are growing and ECS is becoming an important part of obstetrics practice and reproductive planning. The aim of this study is to evaluate the feasibility of a small-size ECS panel in clinical implementation and investigate Chinese couples’ attitudes towards ECS. An ECS panel containing 11 recessive conditions was offered to Chinese pregnant women below 16 gestational weeks. Sequential testing of their partners was recommended for women with a positive carrier status. The reproductive decision and pregnancy outcome were surveyed for at-risk couples. A total of 1321 women performed ECS successfully and the overall carrier rate was 19.23%. The estimated at-risk couple rate was 0.83%. Sequential testing was performed in less than half of male partners. Eight at-risk couples were identified and four of them performed prenatal diagnosis. Our study demonstrated that a small-size ECS panel could yield comparable clinical value to a larger-size panel when the carrier rate of the individual condition is equal or greater than 1%. In addition, more than half of male partners whose wives were carriers declined any types of sequential testing possibly due to a lack of awareness and knowledge of genetic disorders. Genetic education is warranted for the better implementation of ECS.

Current attitudes and preconceptions towards expanded carrier screening in the Eastern Chinese reproductive-aged population

PURPOSE

A growing number of Chinese individuals of reproductive age will face the choice of accepting or refusing expanded carrier screening (ECS). This study aimed to explore the awareness, wishes, and possible misconceptions of ECS among this population, as well as factors affecting their decision-making.

METHODS

Chinese reproductive-aged individuals in Eastern China who sought cell-free fetal DNA screening and peripheral blood karyotype were invited to complete a 31-item ECS survey by scanning a specific quick response code. We evaluated the relationship between awareness, attitudes, and intentions to participate in ECS, along with possible misconceptions.

RESULTS

Overall, 93.1% of participants intended to undergo ECS at their expenses, and 53.6% indicated they would pay less than 1000 CNY (approximately 145 USD) for the test. Around 96.5% of participants had misconceptions about ECS and genetic diseases. Participants whose first reaction was interest, who had prior awareness of the test, or who perceived benefits were more likely to intend to use ECS (p < 0.001). Participants with a bachelor's degree or above or with a household income over 150,000 CNY (approximately 21,700 USD) would be more likely to pay ≥ 1000 CNY (p < 0.05).

CONCLUSIONS

Our study indicates that overall, the Eastern Chinese reproductive-aged population has positive attitudes towards ECS, although there are some misconceptions about ECS and genetic disorders. Population-based ECS appears to be desired by the reproductive-aged people in Eastern China. Steps should be taken to offer ECS along with pre- and post-test education and genetic counseling to raise awareness and to reduce misconceptions.

Assessing clinical education tools for expanded carrier screening

Expanded carrier screening (ECS) is increasingly offered to a broader population and raises challenges of how to best educate and counsel the volume of screened individuals. For this study, we compared three educational tools (brochure, video and comic) about ECS on knowledge and decision making. A convenience online sample of 151 pregnant women was randomized to one of three groups (Video, n = 42; Comic n = 54; Brochure n = 55). Knowledge scores were significantly higher for the comic group compared to the video or the brochure groups (p < .001). No significant differences in preparation for decision making, decisional conflict, or perceptions of shared decision making were identified between the study groups. This study suggests that a comic about ECS may improve patient attention and retention of information. The use of graphic narratives may enable individuals to better understand medical information in general.

Reproductive male partner testing when the female is identified to be a genetic disease carrier

OBJECTIVE

To quantify carrier testing uptake rates for male partners of women found to be a carrier(s) for autosomal recessive conditions and to understand reasons for declining testing (uptake rate).

METHODS

A retrospective chart review of 513 female patients seen at Rutgers-Robert Wood Johnson Medical School found to be carriers through expanded carrier screening (ECS) panels. The aims of this study were to determine how often their male partner chose testing, reasons for declining and the type of methodology chosen for their screening.

RESULTS

Male partner uptake rate was 77%. We identified that the most significant barrier to male partner testing is female patients not following up on their own carrier screening results, thus missing the opportunity for partner testing. When male partners were provided options for testing, the most reported reason for declining is the belief it would have no impact on pregnancy management (20%). A carrier couple rate of 8.3% was identified of partners tested.

CONCLUSION

Despite a relatively high male testing uptake rate, a quarter of carrier females did not proceed with testing their partner. To ascertain fetal risk, results for both parents is necessary. Pretest counseling should stress need for potential male partner follow-up testing.

Optimizing clinical exome design and parallel gene-testing for recessive genetic conditions in preconception carrier screening: Translational research genomic data from 14,125 exomes

Limited translational genomic research data have been reported on the application of exome sequencing and parallel gene testing for preconception carrier screening (PCS). Here, we present individual-level data from a large PCS program in which exome sequencing was routinely performed on either gamete donors (5,845) or infertile patients (8,280) undergoing in vitro fertilization (IVF) treatment without any known family history of inheritable genetic conditions. Individual-level data on pathogenic variants were used to define conditions for PCS based on criteria for severity, penetrance, inheritance pattern, and age of onset. Fetal risk was defined based on actual carrier frequency data accounting for the specific inheritance pattern (fetal disease risk, FDR). In addition, large-scale application of exome sequencing for PCS allowed a deep investigation of the incidence of medically actionable secondary findings in this population. Exome sequencing achieved remarkable clinical sensitivity for reproductive risk of highly penetrant childhood-onset disorders (1/337 conceptions) through analysis of 114 selected gene-condition pairs. A significant contribution to fetal disease risk was observed for rare (carrier rate < 1:100) and X-linked conditions (16.7% and 41.2% of total FDR, respectively). Subgroup analysis of 776 IVF couples identified 37 at increased reproductive risk (4.8%; 95% CI = 3.4–6.5). Further, two additional couples had increased risk for very rare conditions when both members of a parental pair were treated as a unit and the search was extended to the entire exome. About 2.3% of participants showed at least one pathogenic variant for genes included in the updated American College of Medical Genetics and Genomics v2.0 list of secondary findings. Gamete donors and IVF couples showed similar carrier burden for both carrier screening and secondary findings, indicating no causal relationship to fertility. These translational research data will facilitate development of more effective PCS strategies that maximize clinical sensitivity with minimal counterproductive effects.

We provide here crucial information for optimizing the gene-panel design for preconception carrier screening based on the analysis of a large exome sequencing dataset from infertile individuals and gamete donors. Sequencing the entire coding portion of the human genome combined with separate analysis for few relevant genes offers the possibility to detect most of the pathogenetic variants associated with recessive Mendelian diseases and to develop preconception screening strategies that maximise clinical sensitivity with minimal counterproductive effects. Using a large dataset of individual-level exome sequencing data, we have defined gene specific and aggregate fetal risk detectable for conditions selected on discrete criteria of severity, penetrance, inheritance pattern, and age of onset. About 1 out of 300 affected pregnancies can be detected based on a gene-panel of 114 conditions and ~5% of the couples analysed showed an increased risk that warrant consideration from a reproductive viewpoint. These results suggest the use of exome sequencing and parallel gene testing is clinically effective and feasible for preconception carrier screening after proper validation and translational research has been carried out. However, further studies are necessary to define the best framework for clinical implementation and the actual detection rate of at risk couples.

Should Clinicians Leave "Expanded" Carrier Screening Decisions to Patients?

Many patients choose to undergo some type of carrier screening when pregnant or planning to become pregnant. "Expanded" carrier screening products test all patients for the same conditions, regardless of family history, race, or ethnicity. Proponents of expanded screening argue that testing everyone for everything can identify more couples at risk of having an affected fetus. However, most conditions on expanded carrier screening panels do not adhere to criteria recommended by professional organizations and can leave patients with a positive test result but little helpful information about actual clinical risk for their future baby. Confusion persists about whether clinicians should leave carrier screening decisions to patients.

A data-driven evaluation of the size and content of expanded carrier screening panels

PURPOSE

The American College of Obstetricians and Gynecologists (ACOG) proposed seven criteria for expanded carrier screening (ECS) panel design. To ensure that screening for a condition is sufficiently sensitive to identify carriers and reduce residual risk of noncarriers, one criterion requires a per-condition carrier rate greater than 1 in 100. However, it is unestablished whether this threshold corresponds with a loss in clinical detection. The impact of the proposed panel design criteria on at-risk couple detection warrants data-driven evaluation.

METHODS

Carrier rates and at-risk couple rates were calculated in 56,281 patients who underwent a 176-condition ECS and were evaluated for panels satisfying various criteria. Condition-specific clinical detection rates were estimated via simulation.

RESULTS

Different interpretations of the 1-in-100 criterion have variable impact: a compliant panel would include between 3 and 38 conditions, identify 11-81% fewer at-risk couples, and detect 36-79% fewer carriers than a 176-condition panel. If the carrier rate threshold must be exceeded in all ethnicities, ECS panels would lack prevalent conditions like cystic fibrosis. Simulations suggest that the clinical detection rate remains >84% for conditions with carrier rates as low as 1 in 1000.

CONCLUSION

The 1-in-100 criterion limits at-risk couple detection and should be reconsidered.

"A perfect society"- Swedish policymakers' ethical and social views on preconception expanded carrier screening

To improve healthcare policymaking, commentators have recommended the use of evidence, health technology assessment, priority setting, and public engagement in the process of policymaking. Preconception expanded carrier screening, according to the World Health Organization's definition, is a novel health technology and therefore warrants assessment, part of which involves evaluating ethical and social implications. We examined ten Swedish policymakers' perspectives on ethical and social aspects of preconception expanded screening through in-depth expert interviewing, using a semi-structured questionnaire. Respondents were affiliated to governmental and non-governmental institutions that directly influence healthcare policymaking in Sweden. The interviews were recorded, transcribed verbatim, and analyzed via inductive thematic analysis method, which generated seven themes and several subthemes. Policymakers harbored concerns regarding the economics, Swedish and international political respects, implementation procedures, and societal effects, which included long-term ones. Moreover, participants detailed the role of public engagement, research, and responsibility in regard to preconception expanded carrier screening implementation. Since this is a qualitative study, with a small non-random sample, the results may not be generalizable to all policymakers in Sweden. However, the results give a profound insight into the process and interpretative knowledge of experts, in the Swedish milieu and the extent of readiness of Sweden to implement a preconception expanded carrier screening program.

The evolving landscape of expanded carrier screening: challenges and opportunities

Carrier screening allows individuals to learn their chance of passing on an autosomal or X-linked condition to their offspring. Initially introduced as single-disease, ancestry-based screening, technological advances now allow for the possibility of multi-disease, pan-ethnic carrier screening, which we refer to as “expanded carrier screening.” There are numerous potential benefits to expanded carrier screening, including maximizing the opportunity for couples to make autonomous reproductive decisions, and efficiency and marginal additional costs of including more conditions if the test is already being offered. While numerous laboratories currently offer expanded carrier screening services, it is not yet commonly used in clinical practice, and there is a lack of consensus among experts about the service, including whether this should be offered to individuals and couples, whether this should be offered preconception or prenatally, and what conditions to include in screening programs. Challenges for expanded carrier screening programs include a lack of demand from the public, low prioritization by health systems, the potential for pressure to undergo screening, the possibility of disability-based discrimination, needed adaptations to pre- and post-test counseling, technical limitations, and the evolving technological and socio-political landscape.

Structurating Expanded Genetic Carrier Screening: A Longitudinal Analysis of Online News Coverage

Expanded carrier screening (ECS) is a genetic test that is designed to assess the risk of a healthy person passing down a genetic disorder, such as spinal muscular atrophy, to future children. ECS screens for up to several hundred disorders in one test, expanding on traditional carrier screening tests that target one or a few genetic disorders. However, little is known about how this health technology is being presented to the public in media coverage. Accordingly, this study is a qualitative content analysis of online news and information of ECS over a 6-year period, beginning in 2010 when the technology was publicly available. Results indicate that major coverage themes were consistent across the years included, although content within those themes changed over time. Using structuration theory to guide analysis, results reveal that online news and information from 2010 to 2015 structurated ECS as a health technology innovation, an opportunity for business and investment, and a tool for family planning. Results are discussed in terms of implications for future research, for health journalism practice, and for clinical interactions.

Patient actions and reactions after receiving negative results from expanded carrier screening

With the expansion of carrier screening to general preconception and prenatal patient populations, most patients will receive negative results, which we define as indicating <25% risk of having a child with a genetic condition. Because there is limited experience with expanded carrier screening, it is important to understand how receiving negative results affects patients, especially as providers, payers, and policymakers consider whether to offer it. In this mixed-methods study, we asked preconception patients enrolled in the NextGen study about their expectations and experiences receiving negative expanded carrier screening results. Participants completed surveys at study enrollment (n = 110 women, 51 male partners), after receiving carrier results (n = 100 women, 38 male partners), after receiving secondary findings (n = 98 women, 36 male partners), and 6 months after receiving results (n = 95 women, 28 male partners). We also interviewed a subset of participants 12 to 24 months after receiving results (n = 24 women, 12 male partners). We found minimal negative emotional impact and privacy concerns, increased confidence in reproductive plans, and few changes to health behaviors, although some patients made health decisions based on misunderstandings of their results. These findings suggest that expanded carrier screening causes minimal psychosocial harms, but systems are needed to reduce the risk of misinterpreting results.

Business and Breakthrough: Framing (Expanded) Genetic Carrier Screening for the Public

A growing body of research has given attention to issues surrounding genetic testing, including expanded carrier screening (ECS), an elective medical test that allows planning or expecting parents to consider the potential occurrence of genetic diseases and disorders in their children. These studies have noted the role of the mass media in driving public perceptions about such testing, giving particular attention to ways in which coverage of genetics and genetic testing broadly may drive public attitudes and choices concerning the morality, legality, ethics, and parental well-being involved in genetic technologies. However, few studies have explored how mass media are covering the newer test, ECS. Drawing on health-related framing studies that have shown in varying degrees the impact particular frames such as gain/loss and thematic/episodic can have on the public, this study examines the frame selection employed by online media in its coverage of ECS. This analysis-combined with an analysis of the sources and topics used in such coverage and how they relate to selected frames-helps to clarify how mass media are covering an increasingly important medical test and offers considerations of how such coverage may inform mass media scholarship as well as health-related practices.

Pre- and post-testing counseling considerations for the provision of expanded carrier screening: exploration of European geneticists' views

Background

Carrier screening is generally performed with the aim of identifying healthy couples at risk of having a child affected with a monogenic disorder to provide them with reproductive options. Expanded carrier screening (ECS), which provides the opportunity for multiple conditions to be screened in one test, offers a more cost-effective and comprehensive option than screening for single disorders. However, implementation of ECS at a population level would have implications for genetic counseling practice.

Methods

We conducted semi-structured interviews with sixteen European clinical and molecular geneticists with expertise in carrier screening to explore their views on the implementation of ECS in the clinical setting.

Results

Using inductive content analysis, we identified content categories relevant to the pre- and post-test settings. Participants believed ECS would ideally be targeted at couples before pregnancy. There was some disagreement regarding the acceptability of performing ECS in individuals, with several participants actively opposing individual-based screening. In addition, participants discussed the importance of ensuring informed and voluntary participation in ECS, recommending measures to minimize external pressure on prospective parents to undergo testing. A need for adequate counseling to foster informed, autonomous reproductive decision-making and provide support for couples found to be at risk was emphasized.

Conclusions

Practical challenges in optimizing pre-test education and post-test counseling should not be underestimated and they should be carefully addressed before implementing ECS in the clinical setting.

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.

Attitudes of European Geneticists Regarding Expanded Carrier Screening

OBJECTIVE

To explore attitudes of clinical and molecular geneticists about the implementation of multi-disease or expanded carrier screening (ECS) for monogenic recessive disorders.

DESIGN

Qualitative; semistructured interviews.

SETTING

In person or via Skype. Interviews were audiorecorded and transcribed verbatim.

PARTICIPANTS

European clinical and molecular geneticists with expertise in carrier screening (N = 16).

METHODS

Inductive content analysis was used to identify common content categories in the data.

RESULTS

Participants recognized important benefits of ECS, but they also identified major challenges, including limited benefit of ECS for most couples in the general population, lack of knowledge on carrier screening among nongenetic health care providers and the general public, potential negative implications of ECS for society, and limited economic resources. Participants favored an evidence-based approach to the implementation of population-wide ECS and were reluctant to actively offer ECS in the absence of demonstrable benefits. However, there was a consensus among the participants that ECS should be made available to couples who request the test. In addition, they believed ECS could be routinely offered to all people who use assisted reproduction.

CONCLUSION

Although a limited ECS offer is practical, it also raises concerns over equality in access to screening. A comprehensive risk-benefit analysis is needed to determine the desirability of systematic population-wide ECS.

Designing expanded carrier screening panels: results of a qualitative study with European geneticists

Aim: To explore the views of clinical and molecular geneticists on the inclusion of disorders and specific pathogenic mutations into expanded carrier screening (ECS) tests for reproductive purposes. Materials & methods: In-depth semistructured interviews were conducted with 16 European geneticists between April and September 2014. Results: All participants supported carrier screening for severe, childhood-onset autosomal recessive disorders with known natural history. Some participants were also in favor of screening for late-onset and X-linked disorders. Regarding selection of specific pathogenic mutations, our participants argued that ECS should include highly penetrant pathogenic mutations with known genotype–phenotype associations. Conclusion: This study highlights main challenges surrounding the development of ECS panels and offers suggestions for future research in this rapidly advancing field.

Experiences among Women with Positive Prenatal Expanded Carrier Screening Results

The offering and acceptance of expanded carrier screening is increasing among pregnant women including women without an increased risk based on race, ethnicity or family history. The chances of a positive screening test have been reported to be as high as 24 % when multiple conditions are screened. Yet, little is known about the way these tests are offered and how patients are affected by a positive test result. To explore this area of genetic testing, interviews (n = 17) were conducted among women who received positive expanded carrier results in the context of obstetric care. A content analysis was conducted on the transcript data from the interviews. Outcomes of this research suggest that educational interventions are needed to improve maternal understanding of positive carrier screening results. Most of the participants in this study confused the results with other prenatal screening test options. In addition, the way the results were discussed varied greatly, and influenced participants' thoughts about reproductive decisions that led to a range of emotional uncertainty. Our data suggests that genetic counseling improved participants' understanding of positive results. More research is needed to further understand if our results are consistent within a larger, more diverse sample, and to explore how to best provide education about expanded carrier screening.

Evaluation of ACMG-Guideline-Based Variant Classification of Cancer Susceptibility and Non-Cancer-Associated Genes in Families Affected by Breast Cancer

Sequencing tests assaying panels of genes or whole exomes are widely available for cancer risk evaluation. However, methods for classification of variants resulting from this testing are not well studied. We evaluated the ability of a variant-classification methodology based on American College of Medical Genetics and Genomics (ACMG) guidelines to define the rate of mutations and variants of uncertain significance (VUS) in 180 medically relevant genes, including all ACMG-designated reportable cancer and non-cancer-associated genes, in individuals who met guidelines for hereditary cancer risk evaluation. We performed whole-exome sequencing in 404 individuals in 253 families and classified 1,640 variants. Potentially clinically actionable (likely pathogenic [LP] or pathogenic [P]) versus nonactionable (VUS, likely benign, or benign) calls were 95% concordant with locus-specific databases and Clinvar. LP or P mutations were identified in 12 of 25 breast cancer susceptibility genes in 26 families without identified BRCA1/2 mutations (11%). Evaluation of 84 additional genes associated with autosomal-dominant cancer susceptibility identified LP or P mutations in only two additional families (0.8%). However, individuals from 10 of 253 families (3.9%) had incidental LP or P mutations in 32 non-cancer-associated genes, and 9% of individuals were monoallelic carriers of a rare LP or P mutation in 39 genes associated with autosomal-recessive cancer susceptibility. Furthermore, 95% of individuals had at least one VUS. In summary, these data support the clinical utility of ACMG variant-classification guidelines. Additionally, evaluation of extended panels of cancer-associated genes in breast/ovarian cancer families leads to only an incremental clinical benefit but substantially increases the complexity of the results.

Pre- and post-test genetic counseling for chromosomal and Mendelian disorders

Genetic carrier screening, prenatal screening for aneuploidy, and prenatal diagnostic testing have expanded dramatically over the past 2 decades. Driven in part by powerful market forces, new complex testing modalities have become available after limited clinical research. The responsibility for offering these tests lies primarily on the obstetrical care provider and has become more burdensome as the number of testing options expands. Genetic testing in pregnancy is optional, and decisions about undergoing tests, as well as follow-up testing, should be informed and based on individual patients' values and needs. Careful pre- and post-test counseling is central to supporting informed decision-making. This article explores three areas of technical expansion in genetic testing: expanded carrier screening, non-invasive prenatal screening for fetal aneuploidies using cell-free DNA, and diagnostic testing using fetal chromosomal microarray testing, and provides insights aimed at enabling the obstetrical practitioner to better support patients considering these tests.

Kinderwunsch als genetisches Risiko?

Erweiterte präkonzeptionelle Anlageträgerscreenings auf seltene, rezessive Erkrankungen haben sich in jüngster Zeit als neuartige Form genetischer Diagnostik herausgebildet. Bisher werden Tests auf mehr als 100 Anlageträgerschaften von kommerziellen Unternehmen angeboten, eine künftige Übernahme in öffentliche Gesundheitssysteme wird jedoch bereits diskutiert. Falls Mann und Frau die gleiche rezessive Anlage tragen, eröffnet die Diagnostik ihnen verschiedene Alternativen, um die Geburt eines kranken Kindes zu vermeiden. Erweiterte Trägerscreenings haben jedoch problematische gesellschaftliche Implikationen und werfen ungelöste Fragen auf, u. a. wie die getesteten Krankheiten ausgewählt werden und wie eine angemessene genetische Beratung zu gewährleisten ist. Die Vermutung, die Etablierung solcher Screenings sei unvermeidbar, könnte sich als vorschnell erweisen.