Population-based carrier screening for cystic fibrosis: a systematic review of 23 years of research

The Need to Consider Context: A Systematic Review of Factors Involved in the Consent Process for Genetic Tests from the Perspective of Patients

Background: Informed consent for genetic tests is a well-established practice. It should be based on good quality information and in keeping with the patient's values. Existing informed consent assessment tools assess knowledge and values. Nevertheless, there is no consensus on what specific elements need to be discussed or considered in the consent process for genetic tests.Methods: We performed a systematic review to identify all factors involved in the decision-making and consent process about genetic testing, from the perspective of patients. Through public databases, we identified studies reporting factors that influence the decision to accept or decline genetic testing. Studies were included if they reported the perspective of patients or at-risk individuals. All articles were thematically coded.Results: 1989 articles were reviewed: 70 met inclusion criteria and 12 additional articles were identified through the references of included studies. Coding of the 82 articles led to the identification of 45 factors involved in decision-making and consent, which were initially divided into three domains: in favor of, against or with an undetermined influence on genetic testing. Each factor was also divided into three subdomains relating to the informed choice concept: knowledge, values or other. The factors in the "other" subdomain were all related to the context of testing (e.g. timing, cost, influence of family members, etc), and were present in all three domains.Conclusions: We describe the network of factors contributing to decision-making and consent process and identify the context of genetic testing as a third component to influence this process. Future studies should consider the evaluation of contextual factors as an important and relevant component of the consent and decision-making process about genetic tests. Based on these results, we plan to develop and test a more comprehensive tool to assess informed consent for genetic testing.

Prenatal Testing for Variants in Genes Associated with Hereditary Cancer Risk: Laboratory Experience and Considerations

Prenatal molecular genetic testing for familial variants that cause inherited disorders has been performed for decades and is accepted as standard of care. However, the spectrum of genes considered for prenatal testing is expanding because of genetic testing for hereditary cancer risk (HCR) and inclusion of conditions with associated cancer risk in carrier screening panels. A few of these disorders, such as ataxia telangiectasia and Bloom syndrome, include increased cancer risk as part of the phenotype, already meet professional guidelines for prenatal testing, and may be associated with increased cancer risk in heterozygous carriers. In addition, recent studies implicate heterozygosity for variants in lysosomal storage disease genes in HCR etiology. Currently, there is no specific professional guidance regarding prenatal testing for HCR. To determine the prevalence of such testing, we reviewed 1345 consecutive prenatal specimens received in our laboratory for familial variant-specific testing and identified 65 (4.8%) with a known or likely HCR component, plus 210 (15.6%) for lysosomal storage disease. These specimens were classified into five distinct categories for clarity and to enable evaluation. Our experience assessing prenatal specimens for variants associated with HCR, with or without a constitutional phenotype, provides metrics for and contributes to the points to consider in prenatal testing for HCR.

Clinical and genetic features of cystic fibrosis in Japan

Cystic fibrosis (CF) is an autosomal recessive disease caused by pathogenic variants in CF transmembrane conductance regulator (CFTR). While CF is the most common hereditary disease in Caucasians, it is rare in East Asia. In the present study, we have examined clinical features and the spectrum of CFTR variants of CF patients in Japan. Clinical data of 132 CF patients were obtained from the national epidemiological survey since 1994 and CF registry. From 2007 to 2022, 46 patients with definite CF were analyzed for CFTR variants. All exons, their boundaries, and part of promoter region of CFTR were sequenced and the presence of large deletion and duplications were examined by multiplex ligation-dependent probe amplification. CF patients in Japan were found to have chronic sinopulmonary disease (85.6%), exocrine pancreatic insufficiency (66.7%), meconium ileus (35.6%), electrolyte imbalance (21.2%), CF-associated liver disease (14.4%), and CF-related diabetes (6.1%). The median survival age was 25.0 years. The mean BMI percentile was 30.3%ile in definite CF patients aged < 18 years whose CFTR genotypes were known. In 70 CF alleles of East Asia/Japan origin, CFTR-dele16-17a-17b was detected in 24 alleles, the other variants were novel or very rare, and no pathogenic variants were detected in 8 alleles. In 22 CF alleles of Europe origin, F508del was detected in 11 alleles. In summary, clinical phenotype of Japanese CF patients is similar to European patients, but the prognosis is worse. The spectrum of CFTR variants in Japanese CF alleles is entirely different from that in European CF alleles.

Comprehensive analysis of recessive carrier status using exome and genome sequencing data in 1543 Southern Chinese

Traditional carrier screening has been utilized for the detection of carriers of genetic disorders. Since a comprehensive assessment of the carrier frequencies of recessive conditions in the Southern Chinese population is not yet available, we performed a secondary analysis on the spectrum and carrier status for 315 genes causing autosomal recessive disorders in 1543 Southern Chinese individuals with next-generation sequencing data, 1116 with exome sequencing and 427 with genome sequencing data. Our data revealed that 1 in 2 people (47.8% of the population) was a carrier for one or more recessive conditions, and 1 in 12 individuals (8.30% of the population) was a carrier for treatable inherited conditions. In alignment with current American College of Obstetricians and Gynecologists (ACOG) pan-ethnic carrier recommendations, 1 in 26 individuals were identified as carriers of cystic fibrosis, thalassemia, and spinal muscular atrophy in the Southern Chinese population. When the >1% expanded carrier screening rate recommendation by ACOG was used, 11 diseases were found to meet the criteria in the Southern Chinese population. Approximately 1 in 3 individuals (35.5% of the population) were carriers of these 11 conditions. If the 1 in 200 carrier frequency threshold is used, and additional seven genes would meet the criteria, and 2 in 5 individuals (38.7% of the population) would be detected as a carrier. This study provides a comprehensive catalogue of the carrier spectrum and frequency in the Southern Chinese population and can serve as a reference for careful evaluation of the conditions to be included in expanded carrier screening for Southern Chinese people.

Systematic review of outcomes in studies of reproductive genetic carrier screening: Towards development of a core outcome set

PURPOSE

Current practice recommendations support the widespread implementation of reproductive genetic carrier screening (RGCS). These consensus-based recommendations highlight a research gap, with findings from current studies being insufficient to meet the standard required for more rigorous evidence-based recommendations. This systematic review assessed methodological aspects of studies on RGCS to inform the need for a core outcome set.

METHODS

We conducted a systematic search to identify peer-reviewed published studies offering population-based RGCS. Study designs, outcomes, and measurement methods were extracted. A narrative synthesis was conducting using an existing outcome taxonomy and criteria used in the evaluation of genetic screening programs as frameworks.

RESULTS

Sixty-five publications were included. We extracted 120 outcomes representing 24 outcome domains. Heterogeneity in outcome selection, measurement methods and time points of assessment was extensive. Quality appraisal raised concerns for bias. We found that reported outcomes had limited applicability to criteria used to evaluate genetic screening programs.

CONCLUSION

Despite a large body of literature, diverse approaches to research have limited the conclusions that can be cumulatively drawn from this body of evidence. Consensus regarding meaningful outcomes for evaluation of RGCS would be a valuable first step in working towards evidence-based practice recommendations, supporting the development of a core outcome set.

The cost-effectiveness of genotyping versus sequencing for prenatal cystic fibrosis carrier screening

OBJECTIVE

We investigated the cost-effectiveness of three sequential prenatal cystic fibrosis (CF) carrier screening strategies: genotyping both partners, genotyping one partner then sequencing the second, and sequencing both partners.

METHOD

A decision-analytic model compared the strategies in a theoretical cohort of four million pregnant couples in the US population and five racial/ethnic sub-populations. Inputs were obtained from literature and varied in sensitivity analysis. Outcomes included cost per quality-adjusted life year (QALY), missed carrier couples, affected newborns, missed prenatal diagnoses, terminations, and procedure-related losses. The cost-effectiveness threshold was $100,000/QALY.

RESULTS

Sequencing both partners identified 1099 carrier couples that were missed by genotyping both partners, leading to 273 fewer missed prenatal diagnoses, 152 more terminations, and 152 fewer affected newborns. A similar trend was observed in the genotyping followed by sequencing strategy. The incremental cost-effectiveness ratio of genotyping followed by sequencing compared to genotyping both partners was $180,004/QALY and the incremental cost-effectiveness ratio of sequencing both partners compared to genotyping followed by sequencing was $17.6 million/QALY. Sequencing both partners was cost-effective below $339 per test, genotyping/sequencing between $340 and $1837, and genotyping both partners above $1838. Sequencing was not cost-effective among five racial/ethnic sub-populations.

CONCLUSION

Despite improved outcomes, sequencing for prenatal CF carrier screening was not cost-effective compared to genotyping. The clinical significance of the incremental cost-effectiveness of CF carrier screening is a matter of deliberation for public policy debate.

Couples' experiences with expanded carrier screening: evaluation of a university hospital screening offer

Preconception carrier screening offers couples the possibility to receive information about the risk of having a child with a recessive disorder. Since 2016, an expanded carrier screening (ECS) test for 50 severe autosomal recessive disorders has been available at Amsterdam Medical Center, a Dutch university hospital. This mixed-methods study evaluated the experiences of couples that participated in the carrier screening offer, including high-risk participants, as well as participants with a general population risk. All participants received genetic counselling, and pre- (n = 132) and post-test (n = 86) questionnaires and semi-structured interviews (n = 16) were administered. The most important reason to have ECS was to spare a future child a life with a severe disorder (47%). The majority of survey respondents made an informed decision (86%), as assessed by the Multidimensional Measure of Informed Choice. Among the 86 respondents, 27 individual carriers and no new carrier couples were identified. Turn-around time of the test results was considered too long and costs were perceived as too high. Overall, mean levels of anxiety were not clinically elevated. High-risk respondents (n = 89) and pregnant respondents (n = 13) experienced higher levels of anxiety before testing, which decreased after receiving the test result. Although not clinically significant, distress was on average higher for carriers compared to non-carriers (p < 0.0001). All respondents would opt for the test again, and 80.2% would recommend it to others. The results suggest that ECS should ideally be offered before pregnancy, to minimise anxiety. This study could inform current and future implementation initiatives of preconception ECS.

The Core Outcome DEvelopment for Carrier Screening (CODECS) study: protocol for development of a core outcome set

Background

Reproductive genetic carrier screening is a type of genetic testing available to those planning a pregnancy, or during their first trimester, to understand their risk of having a child with a severe genetic condition. There is a lack of consensus for ‘what to measure’ in studies on this intervention, leading to heterogeneity in choice of outcomes and methods of measurement. Such outcome heterogeneity has implications for the quality and comparability of these studies and has led to a lack of robust research evidence in the literature to inform policy and decision-making around the offer of this screening. As reproductive genetic carrier screening becomes increasingly accessible within the general population, it is timely to investigate the outcomes of this intervention.

Objectives

The development of a core outcome set is an established methodology to address issues with outcome heterogeneity in research. We aim to develop a core outcome set for reproductive genetic carrier screening to clarify and standardise outcomes for research and practice.

Methods

In accordance with guidance from the COMET (Core Outcome Measures in Effectiveness Trials) Initiative, this study will consist of five steps: (i) a systematic review of quantitative studies, using narrative synthesis to identify previously reported outcomes, their definitions, and methods of measurement; (ii) a systematic review of qualitative studies using content analysis to identify excerpts related to patient experience and perspectives that can be interpreted as outcomes; (iii) semi-structured focus groups and interviews with patients who have undertaken reproductive genetic carrier screening to identify outcomes of importance to them; (iv) Delphi survey of key stakeholders, including patients, clinicians, and researchers, to refine and prioritise the list of outcomes generated from the previous steps; and (v) a virtual consensus meeting with a purposive sample of key stakeholders to finalise the core outcome set for reporting.

Discussion

This protocol outlines the core outcome set development process and its novel application in the setting of genetic testing. This core outcome set will support the standardisation of outcome reporting in reproductive carrier screening research and contribute to an evolving literature on outcomes to evaluate genetic testing and genetic counselling as health interventions.

COMET core outcome set registration

http://www.comet-initiative.org/Studies/Details/1381.

Couple-based expanded carrier screening provided by general practitioners to couples in the Dutch general population: psychological outcomes and reproductive intentions

Purpose

The aim of expanded preconception carrier screening (ECS) is to inform any couple wishing to conceive about their chances of having children with severe autosomal or X-linked recessive conditions. Responsible implementation of ECS as reproductive genetic screening in routine care requires assessment of benefits and harms. We examined the psychological outcomes of couple-based ECS for 50 autosomal recessive (AR) conditions provided by general practitioners (GPs) to couples from the Dutch general population.

Methods

Dutch GPs invited 4,295 women aged 18–40. We examined anxiety (State-Trait Anxiety Inventory, STAI-6), worry, decisional conflict (DCS) over time in participants declining GP counseling or attending GP counseling with/without testing.

Results

One hundred ninety couples participated; 130 attended counseling, of whom 117 proceeded with testing. No carrier couples were identified. Before counseling, worry (median 6.0) and anxiety (mean 30–34) were low and lower than the population reference (36.4), although some individuals reported increased anxiety or worry. At follow-up, test acceptors reported less anxiety than test decliners (mean 29 vs. 35); differences in anxiety after testing compared to before counseling were not meaningful. Most participants (90%) were satisfied with their decision (not) to undergo testing.

Conclusion

Some individuals reported temporarily clinically relevant distress. Overall, the psychological outcomes are acceptable and no barrier to population-wide implementation.

The prevalence, genetic complexity and population-specific founder effects of human autosomal recessive disorders

Autosomal recessive (AR) disorders pose a significant burden for public health. However, despite their clinical importance, epidemiology and molecular genetics of many AR diseases remain poorly characterized. Here, we analyzed the genetic variability of 508 genes associated with AR disorders based on sequencing data from 141,456 individuals across seven ethnogeographic groups by integrating variants with documented pathogenicity from ClinVar, with stringent functionality predictions for variants with unknown pathogenicity. We first validated our model using 85 diseases for which population-specific prevalence data were available and found that our estimates strongly correlated with the respective clinically observed disease frequencies (r = 0.68; p < 0.0001). We found striking differences in population-specific disease prevalence with 101 AR diseases (27%) being limited to specific populations, while an additional 305 diseases (68%) differed more than tenfold across major ethnogeographic groups. Furthermore, by analyzing genetic AR disease complexity, we confirm founder effects for cystic fibrosis and Stargardt disease, and provide strong evidences for >25 additional population-specific founder mutations. The presented analyses reveal the molecular genetics of AR diseases with unprecedented resolution and provide insights into epidemiology, complexity, and population-specific founder effects. These data can serve as a powerful resource for clinical geneticists to inform population-adjusted genetic screening programs, particularly in otherwise understudied ethnogeographic groups.

Preconception expanded carrier screening: Impact of information presented by text or video on genetic knowledge and attitudes

Preconception expanded carrier screening (ECS) aims to identify couples with an increased risk of having a child with an autosomal recessive (AR) disorder before pregnancy, thereby enabling reproductive choices. Genetic knowledge and experiential knowledge both influence the uptake of ECS. As people in the general public often lack such knowledge, it is essential to provide appropriate and understandable information when offering ECS. This study investigated the effect of an educational video, compared to an educational text, on the knowledge and attitudes toward preconception ECS in the general population. Both the text and video consisted of a brief educational summary on AR inheritance and on the type of disorders included in ECS, with the progressive neurodegenerative condition mucopolysaccharidosis type III (MPS III) as an example. Participants in the reproductive age were invited in collaboration with a research agency. Respondents (N = 789) were offered an educational video prior to completing an online questionnaire that examined genetic knowledge, the perceived severity of MPS III, perceived risk, and attitudes toward ECS. Outcomes were compared to reference data collected previously in which respondents had been offered an educational text (N = 781). We first again studied the attitudes toward ECS in a smaller educational text group (N = 266) in order to assess whether attitudes had changed over time due to increased media coverage on ECS, which did not reveal any significant changes. Respondents who were offered the video had a better genetic knowledge, perceived MPS III as more severe, perceived their risks higher and were more likely to participate in ECS compared to those who were offered text. Online video may well be used as supportive tool to the genetic counseling process, creating more knowledge on ECS and severe genetic disorders included in preconception screening panels.

Bridging the Gap between Scientific Advancement and Real-World Application: Pediatric Genetic Counseling for Common Syndromes and Single-Gene Disorders

Screening and diagnostic testing for single-gene disorders and common syndromes in the pediatric setting frequently generate data that are challenging to interpret, and the ability to diagnose genetic conditions has outpaced the development of successful treatments or cures. Genetic testing is now integrated purposefully into a variety of primary and specialty care clinics, creating an increased requirement for genetic literacy among providers and patients, as well as a growing need to incorporate genetic counseling services into mainstream clinical practice. The practice of pediatric genetic counseling encompasses a unique combination of skills and training designed to address the evolving psychological, social, educational, medical, and reproductive concerns of patients and their families, which complements the multidisciplinary services of physicians, nurses, and other allied health professionals caring for patients with pediatric-onset genetic conditions. The potential range of genetic counseling needs in the pediatric setting transcends the diagnostic period. The sustained nature of pediatric care presents opportunities for development of trusting and longstanding professional relationships that permit the evolving genetic counseling needs of patients and families to be met. A discussion of cystic fibrosis, a common autosomal recessive single-gene disorder with an increasingly broad clinical spectrum and genotype-phenotype variability, serves as a useful case study to illustrate the current and emerging genetic counseling practices, goals, and challenges impacting patients and their families.

Which types of conditions should be included in reproductive genetic carrier screening? Views of parents of children with a genetic condition

Reproductive genetic carrier screening identifies couples with an increased chance of having children with autosomal and X-linked recessive conditions. Initially only offered for single conditions to people with a high priori risk, carrier screening is becoming increasingly offered to individuals/couples in the general population for a wider range of genetic conditions. Despite advances in genomic testing technology and greater availability of carrier screening panels, there is no consensus around which types of conditions to include in carrier screening panels. This study sought to identify which types of conditions parents of children with a genetic condition believe should be included in carrier screening. Participants (n = 150) were recruited through Royal Children's Hospital (RCH) Melbourne outpatient clinics, the Genetic Support Network of Victoria (GSNV) and a databank of children with hearing loss (VicCHILD). This study found that the majority of participants support offering carrier screening for: neuromuscular conditions (n = 128/134, 95.5%), early fatal neurodegenerative conditions (n = 130/141, 92.2%), chronic multi-system disorders (n = 124/135, 91.9%), conditions which cause intellectual disability (n = 128/139, 92.1%) and treatable metabolic conditions (n = 120/138, 87.0%). Views towards the inclusion of non-syndromic hearing loss (n = 88/135, 65.2%) and preventable adult-onset conditions (n = 75/135, 55.6%) were more mixed. Most participants indicated that they would use reproductive options to avoid having a child with the more clinically severe conditions, but most would not do so for clinically milder conditions. A recurring association was observed between participants' views towards carrier screening and their lived experience of having a child with a genetic condition.

Cost-effectiveness of the CFTR gene-sequencing test for asymptomatic carriers in the Colombian population

Introducción.

La fibrosis quística es una enfermedad genética de carácter autosómico recesivo clasificada como enfermedad huérfana de alto costo.

Objetivo.

Determinar la razón de costo-efectividad de la prueba diagnóstica de secuenciación del gen CFTR para los portadores asintomáticos familiares en primer, segundo y tercer grados de consanguinidad.

Materiales y métodos.

Se hizo una búsqueda sistemática sobre la evaluación de las características operativas de la prueba diagnóstica y los modelos de árbol de decisiones en estudios de costo-efectividad. Se elaboró un modelo de árbol de decisiones tomando como unidad de análisis la prevención de futuras concepciones. Los costos de la enfermedad se obtuvieron del reporte de alto costo del Ministerio de Salud de Colombia. Los costos de la prueba se obtuvieron de laboratorios nacionales. Se hizo un análisis de sensibilidad, determinístico y probabilístico, con la perspectiva del tercer pagador y horizonte a un año.

Resultados.

Se obtuvo una razón incremental de costo-efectividad (RICE) de USD$ 5.051,10 por obtener 10,89 % más de probabilidades de evitar el nacimiento de un niño enfermo con fibrosis quística por pareja. Para los familiares de segundo y tercer grados, se encontró una RICE de USD$ 19.380,94 y USD$ 55.913,53, respectivamente, al aplicar el PIB per cápita. Esta tecnología fue costo-efectiva en 39 %, 61,18 % y 74,36 % para 1, 2 y 3 PIB per cápita en familiares de primer grado de consanguinidad.

Conclusiones.

La prueba genética de detección de portadores del gen CFTR resultó costo-efectiva dependiendo del umbral de la disponibilidad de pagar, y de los supuestos y limitaciones establecidas en el modelo.

Characterization of Ancestral Origin of Cystic Fibrosis of Patients with New Reported Mutations in CFTR

The incidence of cystic fibrosis (CF) and the frequency of the variants reported for CFTR depend on the population; furthermore, CF symptomatology is characterized by obstructive lung disease and pancreatic insufficiency among other symptoms, which are reliant on the individual's genotype. The Ecuadorian population is a mixture of Native Americans, Europeans, and Africans. That population admixture could be the reason for the new mutations reported in a previous study by Ruiz et al. (2019). A panel of 46 Ancestry Informative Markers was used to estimate the ancestral proportions of each available sample (12 samples in total). As a result, the Native American ancestry proportion was the most prevalent in almost all individuals, except for three patients from Guayaquil with the mutation [c.757G>A:p.Gly253Arg; c.1352G>T:p.Gly451Val] who had the highest European composition.

Attitudes of relatives of mucopolysaccharidosis type III patients toward preconception expanded carrier screening

Preconception expanded carrier screening (ECS) aims to detect carrier couples of autosomal recessive (AR) disorders before pregnancy in order to increase reproductive autonomy of prospective parents. Genetic knowledge and knowledge gained from experience influence decision making on participation in genetic testing and understanding carrier test results. In this study we assessed whether parents and relatives of patients with the severe AR condition mucopolysaccharidosis type III (MPS III), who are expected to have genetic and experiential knowledge, have more positive attitudes toward ECS than the Dutch reference group. Parents of all MPS III patients known to the Dutch expert center were invited to participate and asked to invite first and second degree relatives. The online questionnaire started with an educational text, and assessed attitudes toward ECS, genetic knowledge and perceived MPS III severity. Results were compared with the Dutch population. Parents and relatives of MPS III patients (n = 159) scored higher on the genetic knowledge test and perceived MPS III as more severe compared with the general Dutch population (n = 781). Parents and relatives reported to be more likely to participate in ECS (84.3% and 62.5%, respectively) compared with the public (31%) (p < 0.001). Being a relative of a MPS III patient was the strongest variable in the regression analyses for intended ECS participation. Our results show that genetic knowledge influences ECS decision making. Therefore, appropriate information on ECS and genetic counseling is needed to enable prospective parents from the general population, including relatives of patients with severe hereditary disorders, to make informed decisions.

Interest in expanded carrier screening among individuals and couples in the general population: systematic review of the literature

BACKGROUND

Through carrier screening, prospective parents can acquire information about whether they have an increased risk of conceiving a child affected with an autosomal recessive or X-linked condition. Within the last decade, advances in genomic technologies have facilitated a shift from condition-directed carrier screening to expanded carrier screening (ECS). Following the introduction of ECS, several studies have been performed to gauge the interest in this new technology among individuals and couples in the general population.

OBJECTIVE AND RATIONALE

The aim of this systematic review was to synthesize evidence from empirical studies that assess the interest in ECS among individuals and couples in the general population. As the availability and accessibility of ECS grow, more couples who are a priori not at risk based on their personal or family history will be presented with the choice to accept or decline such an offer. Their attitudes and beliefs, as well as the perceived usefulness of this screening modality, will likely determine whether ECS is to become a widespread reproductive genetic test.

SEARCH METHODS

Four databases (Pubmed, Web of Science, CINAHL, Cochrane Library) were systematically searched to identify English language studies performed between January 2009 and January 2019 using the following search terms: carrier screening, carrier testing, attitudes, intention, interest, views, opinions, perspectives and uptake. Studies were eligible for inclusion if they reported on intentions to undergo a (hypothetical) ECS test, uptake of an actual ECS offer or both. Two researchers performed a multistep selection process independently for validation purposes.

OUTCOMES

Twelve empirical studies performed between 2015 and 2019 were included for analysis. The studies originated from the USA (n = 6), the Netherlands (n = 3), Belgium (n = 1), Sweden (n = 1) and Australia (n = 1). The sample size of the studies varied from 80 to 1669. In the included studies, 32%–76% of respondents were interested in a (hypothetical) ECS test, while uptake rates for actual ECS offers ranged from 8% to 50%. The highest overall uptake was observed when ECS was offered to pregnant women (50%). By contrast, studies focusing on the preconception population reported lower overall uptake rates (8–34%) with the exception of one study where women were counseled preconception in preparation for IVF (68.7%).

WIDER IMPLICATIONS

Our findings suggest that there may be discrepancies between prospective parents’ reported intentions to undergo ECS and their actual uptake, particularly during the preconception period. As ECS is a new and relatively unknown test for most future parents, the awareness and comprehension within the general population could be rather limited. Adequate pre- and post-test counseling services should be made available to couples offered ECS to ensure informed reproductive decision-making, together with guidelines for primary health care professionals. Due to restricted nature of the samples and methods of the underlying primary studies, some of the reported results might not be transferable to a broader population. More research is needed to see if the observed trends also apply to a broader and more diverse population.

Sequencing as a first-line methodology for cystic fibrosis carrier screening

Purpose

Medical society guidelines recommend offering genotyping-based cystic fibrosis (CF) carrier screening to pregnant women or women considering pregnancy. We assessed the performance of sequencing-based CF screening relative to genotyping, in terms of analytical validity, clinical validity, clinical impact, and clinical utility.

Methods

Analytical validity was assessed using orthogonal confirmation and reference samples. Clinical validity was evaluated using the CFTR2 database. Clinical impact was assessed using ~100,000 screened patients. Three screening strategies were compared: genotyping 23 guideline-recommended variants (“CF23”), sequencing all coding bases in CFTR (“NGS”), and sequencing with large copy-number variant (CNV) identification (“NGS + CNV”). Clinical utility was determined via self-reported actions of at-risk couples (ARCs).

Results

Analytical accuracy of NGS + CNV was 100% for SNVs, indels, and CNVs; interpretive clinical specificity relative to CFTR2 was 99.5%. NGS + CNV detected 58 ARCs, 18 of whom would have gone undetected with CF23 alone. Most ARCs (89% screened preconceptionally, 56% prenatally) altered pregnancy management, and no significant differences were observed between ARCs with or without at least one non-CF23 variant.

Conclusion

Modern NGS and variant interpretation enable accurate sequencing-based CF screening. Limiting screening to 23 variants does not improve analytical validity, clinical validity, or clinical utility, but does fail to detect approximately 30% (18/58) of ARCs.

Giving adolescents a voice: the types of genetic information adolescents choose to learn and why

PURPOSE

The American College of Medical Genetics and Genomics supports parents' opting in or out of secondary analysis of 59 genes when their child has clinical exome/genome sequencing. We explored the reasons adolescents choose to learn certain types of results and the reasons they want to involve or not involve parents in decision-making.

METHODS

Adolescents recruited without clinical indication were offered independent, followed by joint choices with a parent to learn genomic results. After making independent choices, adolescent/parent dyads were interviewed to explore the reasons for their choices. Interviews were audio-recorded and transcribed. The constant comparative method was used to analyze 64 purposefully selected transcripts that included 31 from adolescents who excluded some or all potential results.

RESULTS

Three major themes informed adolescents' choices: (1) actionability of information, (2) knowledge seeking, and (3) psychological impact. Of adolescents who independently excluded some conditions (n=31), 58% changed their initial choices during the joint interview due to parental influence or improved understanding. Nearly all adolescents (98%) wanted to be involved in the decision-making process, and 53% wanted to make choices independently.

CONCLUSIONS

Our findings contribute empirical evidence to support the refinement of professional guidelines for adolescents' engagement and preferences in genetic testing decisions.

Attitudes of the general population towards preconception expanded carrier screening for autosomal recessive disorders including inborn errors of metabolism

BACKGROUND

A substantial number of severely debilitating and often ultimately fatal inborn errors of metabolism (IEMs) still lack an effective disease-modifying treatment. Informing couples before a pregnancy about an increased risk of having a child with an inherited disorder is now feasible by preconception expanded carrier screening (ECS). While knowledge about carrier status enhances reproductive autonomy, it may also result in ethical dilemmas. The purpose of this study was to assess the attitudes of the general Dutch population towards preconception ECS and to investigate which factors influence these attitudes.

METHODS

Data collection was carried out in collaboration with a market research agency. In total, 1188 Dutch individuals of reproductive age (18-45 years) were invited by email to complete an online ECS questionnaire in 2016. Prior to the start of the questionnaire, a written explanation of the concepts of autosomal recessive (AR) inheritance, carrier status and ECS was presented.

RESULTS

The questionnaire was completed by 781 individuals (65.7%), of whom 31% indicated they would take an ECS test themselves. In addition, 55% agreed that ECS should be offered to all prospective parents. The most frequently selected argument in favor of ECS (47.2%) was that participants want to spare a child from a life with a severe hereditary disorder. The reason most often mentioned not to participate in ECS (48%) was that participants reported not having a hereditary disorder in the family. The majority preferred receiving individual test results above a couple-based disclosure method in which participants receive the carrier status results only when they are a carrier couple of the same disorder. Participants with religious beliefs were less likely to participate in ECS, whereas participants who were considering a (future) pregnancy were more likely to participate.

CONCLUSION

Our study demonstrates an overall positive attitude among participants of reproductive age in the general Dutch population towards preconception ECS. A striking misconception is that many of the participants believe that ECS is of interest only for those with a positive family history of one of the hereditary disorders. This finding emphasizes the importance of providing understandable, balanced information and education to the general public regarding the concepts of inheritance when presenting the option of carrier screening. Our results provide valuable insights that can be used in the debate about the responsible implementation of preconception ECS for AR disorders, including IEMs.

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.

Direct-to-consumer carrier screening for cystic fibrosis via a hospital website: a 6-year evaluation

A Dutch university hospital started offering cystic fibrosis (CF) carrier screening directly to consumers (DTC) through their website in 2010. A 6-year process evaluation was conducted to evaluate the offer. Screening was implemented as intended. However, uptake was lower than expected. Forty-four tests have been requested, partly by couples with a positive family history for CF, which was not the intended target group. Users were generally positive about the screening offer, citing accessibility, ease of testing, anonymity, and perceived shortcomings of regular healthcare as reasons for requesting screening. DTC CF carrier screening via a university hospital website is feasible, but is seldom used. Considering technological advances, continuation of this specific offer is questionable.

Approaches to carrier testing and results disclosure in translational genomics research: The clinical sequencing exploratory research consortium experience

Background

Clinical genome and exome sequencing (CGES) is primarily used to address specific clinical concerns by detecting risk of future disease, clarifying diagnosis, or directing treatment. Additionally, CGES makes possible the disclosure of autosomal recessive and X‐linked carrier results as additional secondary findings, and research about the impact of carrier results disclosure in this context is needed.

Methods

Representatives from 11 projects in the clinical sequencing exploratory research (CSER) consortium collected data from their projects using a structured survey. The survey focused on project characteristics, which variants were offered and/or disclosed to participants as carrier results, methods for carrier results disclosure, and project‐specific outcomes. We recorded quantitative responses and report descriptive statistics with the aim of describing the variability in approaches to disclosing carrier results in translational genomics research projects.

Results

The proportion of participants with carrier results was related to the number of genes included, ranging from 3% (three genes) to 92% (4,600 genes). Between one and seven results were disclosed to those participants who received any positive result. Most projects offered participants choices about whether to receive some or all of the carrier results. There were a range of approaches to communicate results, and many projects used separate approaches for disclosing positive and negative results.

Conclusion

Future translational genomics research projects will need to make decisions regarding whether and how to disclose carrier results. The CSER consortium experience identifies approaches that balance potential participant interest while limiting impact on project resources.

Measuring the impact of genetic knowledge on intentions and attitudes of the community towards expanded preconception carrier screening

BACKGROUND

Preconception carrier screening (PCS) provides the potential to empower couples to make reproductive choices before having an affected child. An important question is what factors influence the decision to use or not use PCS.

METHODS

We analysed the relationship between knowledge, attitudes and intentions to participate in PCS using logistic regression in 832 participants in Western Australia.

RESULTS

Two-thirds of participants said they would take the test, with 92% of these supporting screening for diseases reducing the lifespan of children and infants. Those who had good genetic knowledge were seven times more likely to intend to use PCS (p≤0.001), while those with high genetic knowledge were four times more likely to (p=0.002) and raised concerns such as insurance and confidentiality.Decreasing genetic knowledge correlated positively with religiosity and apprehension (p≤0.001), which correlated negatively with intention to use PCS (p≤0.001). Increasing genetic knowledge correlated positively with factors representing positive attitudes (p≤0.001), which correlated positively with intention to use PCS (p≤0.001). Many participants with good genetic knowledge nevertheless answered questions that tested understanding incorrectly.80% of participants stated they would prefer to access the test through their general practitioners and 30% would pay up to $A200.

CONCLUSIONS

Knowledge is instrumental in influencing participation. Having good genetic knowledge may not be enough to understand core concepts of PCS and may impact informed decision-making. This study recommends that continuous education of health professionals and thus the community, in PCS is crucial to reduce misconceptions.

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.

Joint SOGC-CCMG Opinion for Reproductive Genetic Carrier Screening: An Update for All Canadian Providers of Maternity and Reproductive Healthcare in the Era of Direct-to-Consumer Testing

OBJECTIVE

This guideline was written to update Canadian maternity care and reproductive healthcare providers on pre- and postconceptional reproductive carrier screening for women or couples who may be at risk of being carriers for autosomal recessive (AR), autosomal dominant (AD), or X-linked (XL) conditions, with risk of transmission to the fetus. Four previous SOGC- Canadian College of Medical Geneticists (CCMG) guidelines are updated and merged into the current document.

INTENDED USERS

All maternity care (most responsible health provider [MRHP]) and paediatric providers; maternity nursing; nurse practitioner; provincial maternity care administrator; medical student; and postgraduate resident year 1-7.

TARGET POPULATION

Fertile, sexually active females and their fertile, sexually active male partners who are either planning a pregnancy or are pregnant (preferably in the first trimester of pregnancy, but any gestational age is acceptable).

OPTIONS

Women and their partners will be able to obtain appropriate genetic carrier screening information and possible diagnosis of AR, AD, or XL disorders (preferably pre-conception), thereby allowing an informed choice regarding genetic carrier screening and reproductive options (e.g., prenatal diagnosis, preimplantation genetic diagnosis, egg or sperm donation, or adoption).

OUTCOMES

Informed reproductive decisions related to genetic carrier screening and reproductive outcomes based on family history, ethnic background, past obstetrical history, known carrier status, or genetic diagnosis. SOGC REPRODUCTIVE CARRIER SCREENING SUMMARY STATEMENT (2016): Pre-conception or prenatal education and counselling for reproductive carrier screening requires a discussion about testing within the three perinatal genetic carrier screening/diagnosis time periods, which include pre-conception, prenatal, and neonatal for conditions currently being screened for and diagnosed. This new information should be added to the standard reproductive carrier screening protocols that are already being utilized by the most responsible maternity provider through the informed consent process with the patient. (III-A; GRADE low/moderate) SOGC OVERVIEW OF RECOMMENDATIONS QUALITY AND GRADE: There was a strong observational/expert opinion (quality and grade) for the genetic carrier literature with randomized controlled trial evidence being available only for the invasive testing. Both the Canadian Task Force on Preventive Health Care quality and classification and the GRADE evidence quality and grade are provided.

EVIDENCE

MEDLINE; PubMed; government neonatal screening websites; key words/common reproductive genetic carrier screened diseases/previous SOGC Guidelines/medical academic societies (Society of Maternal-Fetal Medicine [SMFM]; American College of Medical Genetics and Genomics; American College of Obstetricians and Gynecologists [ACOG]; CCMG; Royal College Obstetrics and Gynaecology [RCOG] [UK]; American Society of Human Genetics [ASHG]; International Society of Prenatal Diagnosis [ISPD])/provincial neonatal screening policies and programs; search terms (carrier screening, prenatal screening, neonatal genetic/metabolic screening, cystic fibrosis (CF), thalassemia, hemoglobinopathy, hemophilia, Fragile X syndrome (FXS), spinal muscular atrophy, Ashkenazi Jewish carrier screening, genetic carrier screening protocols, AR, AD, XL).

SEARCH PERIOD

10 years (June 2005-September 2015); initial search dates June 30, 2015 and September 15, 2015; completed final search January 4, 2016. Validation of articles was completed by primary authors RD Wilson and I De Bie.

BENEFITS, HARMS, AND COST

Benefits are to provide an evidenced based reproductive genetic carrier screening update consensus based on international opinions and publications for the use of Canadian women, who are planning a pregnancy or who are pregnant and have been identified to be at risk (personal or male partner family or reproductive history) for the transmission of a clinically significant genetic condition to their offspring with associated morbidity and/or mortality. Harm may arise from having counselling and informed testing of the carrier status of the mother, their partner, or their fetus, as well as from declining to have this counselling and informed testing or from not having the opportunity for counselling and informed testing. Costs will ensue both from the provision of opportunities for counselling and testing, as well as when no such opportunities are offered or are declined and the birth of a child with a significant inherited condition and resulting morbidity/mortality occurs; these comprise not only the health care costs to the system but also the social/financial/psychological/emotional costs to the family. These recommendations are based on expert opinion and have not been subjected to a health economics assessment and local or provincial implementation will be required.

GUIDELINE UPDATE

This guideline is an update of four previous joint SOGC-CCMG Genetic Screening Guidelines dated 2002, 2006, 2008, and 2008 developed by the SOGC Genetic Committee in collaboration with the CCMG Prenatal Diagnosis Committee (now Clinical Practice Committee). 2016 CARRIER SCREENING RECOMMENDATIONS.

Preconception carrier screening for multiple disorders: evaluation of a screening offer in a Dutch founder population

Technological developments have enabled carrier screening for multiple disorders. This study evaluated experiences with a preconception carrier screening offer for four recessive disorders in a Dutch founder population. Questionnaires were completed by 182 attendees pretesting and posttesting and by 137 non-attendees. Semistructured interviews were conducted with seven of the eight carrier couples. Attendees were mainly informed about the existence of screening by friends/colleagues (49%) and family members (44%). Familiarity with the genetic disorders was high. Knowledge after counseling increased (p < 0.001); however, still 9%, compared to 29% before counseling, wrongly mentioned an increased risk of having an affected child if both parents are carriers of different disorders. Most attendees (97%) recalled their test results correctly, but two couples reported being carrier of another disorder than reported. Overall, 63% felt worried while waiting for results but anxiety levels returned to normal afterwards. In all, 2/39 (5%) carriers felt less healthy. Screened individuals were very satisfied; they did not regret testing (97%) and would recommend testing to others (97%). The majority (94%) stated that couples should always have a pretest consultation, preferably by a genetic counselor rather than their general practitioner (83%). All carrier couples made reproductive decisions based on their results. Main reason for non-attendance was unawareness of the screening offer. With expanded carrier screening, adequately informing couples pretest and posttesting is of foremost importance. Close influencers (family/friends) can be used to raise awareness of a screening offer. Our findings provide lessons for the implementation of expanded carrier screening panels in other communities and other settings.

Factors for successful implementation of population-based expanded carrier screening: learning from existing initiatives

Background: Carrier screening for autosomal recessive disorders aims to facilitate reproductive decision-making by identifying couples with a 1-in-4 risk in every pregnancy of having an affected child. Except for a few countries or regions, carrier screening is not widely offered and is mostly ancestry-based. Technological advances enable carrier screening for multiple diseases simultaneously allowing universal screening regardless of ancestry (population-based expanded carrier screening). It is important to study how this can be successfully implemented. This study therefore aims to identify critical factors involved in successful implementation, from a user perspective, by learning from already implemented initiatives. Methods: Factors associated with successful implementation were identified by: (i) a literature review and (ii) two case studies; studying experiences with carrier screening in two high-risk communities (a Dutch founder population and the Ashkenazi Jewish population), including a survey among community members. Results: Factors identified were familiarity with (specific) genetic diseases and its availability, high perceived benefits of screening (e.g. screening avoids much suffering), acceptance of reproductive options, perceived risk of being a carrier and low perceived social barriers (e.g. stigmatization). In contrast to the Jewish community, the initial demand for screening in the Dutch founder population did not entirely come from the community itself. However, the large social cohesion of the community facilitated the implementation process. Conclusion: To ensure successful implementation of population-based expanded carrier screening, efforts should be made to increase knowledge about genetic diseases, create awareness and address personal benefits of screening in a non-directive way.

Experiences of a High-Risk Population with Prenatal Hemoglobinopathy Carrier Screening in a Primary Care Setting: a Qualitative Study

Carrier screening for hemoglobinopathies (HbPs; sickle cell disease and thalassemia) aims to facilitate autonomous reproductive decision-making. In the absence of a Dutch national HbP carrier screening program, some primary care midwives offer screening on an ad hoc basis. This qualitative descriptive study explores how pregnant women perceive an offer of HbP carrier screening by their midwife. Semi-structured interviews (n = 26) were conducted with pregnant women at risk of being a HbP carrier, and whom were offered screening at their booking appointment in one of two midwifery practices in Amsterdam. The results showed that half of the respondents were familiar with HbPs. Generally, women perceived the offer of HbP carrier screening as positive, and most women (n = 19) accepted screening. Seven declined, of whom two already knew their carrier status. Important reasons to accept screening were to obtain knowledge about their own carrier status and health of their unborn child, and the ease of the procedure. A multistep process of decision-making was observed, as many women did not give follow-up testing (e.g. partner, invasive diagnostics) much consideration while deciding on accepting or declining HbP screening. Women experienced information overload, and preferred receiving the information at a different moment (e.g. before the intake by a leaflet, or preconceptionally). In conclusion, while prenatal HbP carrier screening is perceived as positive, informed decision-making seems to be suboptimal, and both the content and timing of the information provided needs improvement.

Expanded carrier screening: what determines intended participation and can this be influenced by message framing and narrative information?

Next-generation sequencing enabled us to create a population-based expanded carrier screening (ECS) test that simultaneously tests for 50 serious autosomal recessive diseases. Before offering this test universally, we wanted to know what factors are related to intended participation and how the general public can be informed about the test without being influenced in their intention to participate. We studied this by measuring to what extent 'message framing' and 'narrative information' can influence people's intended participation. Data were collected by means of an online survey of 504 potential users, and the factors examined were based on the Theory of Planned Behaviour and on previous research on intended participation in preconception carrier screening. Message framing was manipulated by explaining the risk of couple carriership in different ways, while narrative information was provided to only half of the respondents. The factors most positively related to intended participation were perceiving benefits of the screening, having a positive attitude towards the screening, having no religion, having an actual child wish and experiencing the choice to participate as easy. Perceived benefits and a positive attitude were most influential factors by far. Message framing and narrative information had no significant effect on intended participation, reinforcing that message framing and narrative information can help to inform the general public about ECS without influencing their intended participation. Future research should study if the importance of perceived benefits and a positive attitude can be replicated when other factors are included and when actual participation is measured instead of intended participation.

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.

Outcomes of an International Workshop on Preconception Expanded Carrier Screening: Some Considerations for Governments

Background

Consideration of expanded carrier screening has become an emerging issue for governments. However, traditional criteria for decision-making regarding screening programs do not incorporate all the issues relevant to expanded carrier screening. Further, there is a lack of consistent guidance in the literature regarding the development of appropriate criteria for government assessment of expanded carrier screening. Given this, a workshop was held to identify key public policy issues related to preconception expanded carrier screening, which governments should consider when deciding whether to publicly fund such programs.

Methods

In June 2015, a satellite workshop was held at the European Society of Human Genetics Conference. It was structured around two design features: (1) the provision of information from a range of perspectives and (2) small group deliberations on the key issues that governments need to consider and the benefits, risks, and challenges of implementing publicly funded whole-population preconception carrier screening.

Results

Forty-one international experts attended the workshop. The deliberations centered primarily on the conditions to be tested and the elements of the screening program itself. Participants expected only severe conditions to be screened but were concerned about the lack of a consensus definition of “severe.” Issues raised regarding the screening program included the purpose, benefits, harms, target population, program acceptability, components of a program, and economic evaluation. Participants also made arguments for consideration of the accuracy of screening tests.

Conclusion

A wide range of issues require careful consideration by governments that want to assess expanded carrier screening. Traditional criteria for government decision-making regarding screening programs are not a “best fit” for expanded carrier screening and new models of decision-making with appropriate criteria are required. There is a need to define what a “severe” condition is, to build evidence regarding the reliability and accuracy of screening tests, to consider the equitable availability and downstream effects on and costs of follow-up interventions for those identified as carriers, and to explore the ways in which the components of a screening program would be impacted by unique features of expanded carrier screening.

Swedish parents' interest in preconception genetic carrier screening

INTRODUCTION

Genetic technologies advance rapidly. It is possible to undergo genetic carrier screening before pregnancy to examine genetic risks to future offspring. We aimed to investigate parents' interest and motives towards preconception genetic carrier screening (PCS) as well as factors associated with interest in PCS.

MATERIAL AND METHODS

Our study sample consists of 777 parent couples within the longitudinal Swedish Pregnancy Planning study. Women responded to questionnaires at three occasions: in early pregnancy, late pregnancy, and one year after childbirth. Male partners responded to one questionnaire one year after childbirth.

RESULTS

One-third of the parents were positive (30% versus 34% of women and men, respectively), less than a third were negative (26% versus 28%), and 45% versus 38% were uncertain about whether to consider PCS before a future pregnancy. No differences in PCS interest were found between women and men (P = 0.091), but a higher proportion of women were concerned about negative consequences (53% versus 46%, P < 0.003) and were 'opposed to such a way of child selection' (31.8% versus 25.2%, P = 0.002). Factors associated with PCS interest were experiences of prenatal diagnostics and positive attitudes towards finding out or choosing sex of one's child (women), and prenatal diagnostics, self-rated poor health, and pregnancy planning (men).

CONCLUSION

Both women and men had relatively high uncertainty towards PCS, but women were more concerned about negative consequences. The future extent of the clinical utility of PCS is currently unknown, but parents' interests and doubts are important aspects to consider.

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.

Population-based preconception carrier screening: how potential users from the general population view a test for 50 serious diseases

With the increased international focus on personalized health care and preventive medicine, next-generation sequencing (NGS) has substantially expanded the options for carrier screening of serious, recessively inherited diseases. NGS screening tests not only offer reproductive options not previously available to couples, but they may also ultimately reduce the number of children born with devastating disorders. To date, preconception carrier screening (PCS) has largely targeted single diseases such as cystic fibrosis, but NGS allows the testing of many genes or diseases simultaneously. We have developed an expanded NGS PCS test for couples; simultaneously it covers 50 very serious, early-onset, autosomal recessive diseases that are untreatable. This is the first, noncommercial, population-based, expanded PCS test to be offered prospectively to couples in a health-care setting in Europe. So far, little is known about how potential users view such a PCS test. We therefore performed an online survey in 2014 among 500 people from the target population in the Netherlands. We enquired about their intention to take an expanded PCS test if one was offered, and through which provider they would like to see it offered. One-third of the respondents said they would take such a test were it to be offered. The majority (44%) preferred the test to be offered via their general practitioner (GP) and 58% would be willing to pay for the test, with a median cost of [euro ]75. Our next step is to perform an implementation study in which this PCS test will be provided via selected GPs in the Northern Netherlands.

Responsible implementation of expanded carrier screening

This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines.

"It gives them more options": preferences for preconception genetic carrier screening for fragile X syndrome in primary healthcare

This study aims to explore stakeholder views about offering population-based genetic carrier screening for fragile X syndrome. A qualitative study using interviews and focus groups with stakeholders was undertaken to allow for an in-depth exploration of views and perceptions about practicalities of, and strategies for, offering carrier screening for fragile X syndrome to the general population in healthcare settings. A total of 188 stakeholders took part including healthcare providers (n = 81), relatives of people with fragile X syndrome (n = 29), and members of the general community (n = 78). The importance of raising community awareness about screening and providing appropriate support for carriers was emphasized. There was a preference for preconception carrier screening and for providing people with the opportunity to make an informed decision about screening. Primary care was highlighted as a setting which would ensure screening is accessible; however, challenges of offering screening in primary care were identified including time to discuss screening, knowledge about the test and possible outcomes, and the health professionals' approach to offering screening. With the increasing availability of genetic carrier tests, it is essential that research now focuses on evaluating approaches for the delivery of carrier screening programs. Primary healthcare is perceived as an appropriate setting through which to access the target population, and raising awareness is essential to making genetic screening more accessible to the general community.

The impact of a national population carrier screening program on cystic fibrosis birth rate and age at diagnosis: Implications for newborn screening

BACKGROUND

Population carrier screening (PCS) has been available in Israel since 1999 and universally subsidized since 2008. We sought to evaluate its impact.

METHODS

A retrospective review of governmental databanks, the national CF registry and CF centers.

RESULTS

CF rate per 100,000 live births has decreased from 14.5 in 1990 to 6 in 2011. From 2004-2011 there were 95 CF births: 22 utilized PCS; 68 (72%) had 2 known CFTR mutations; 37% were pancreatic sufficient. At diagnosis, age was 6 (0-98) months; 53/95 had respiratory symptoms, 41/95 failure to thrive and 19/95 pseudomonas. Thirty-four (36%) were Arabs and 19 (20%) orthodox Jews, compared to 20% and 8% respectively, in the general population.

CONCLUSIONS

PCS markedly reduced CF birth rates with a shift towards milder mutations, but was often avoided for cultural reasons. As children regularly have significant disease at diagnosis, we suggest a balanced approach, utilizing both PCS and newborn screening.

"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.

Human Genetics Society of Australasia position statement: population-based carrier screening for cystic fibrosis

Since the discovery in 1989 that mutations in cystic fibrosis transmembrane conductance regulator (CFTR) underlie cystic fibrosis (CF), the most common life shortening genetic disorder in Caucasians, it has been possible to identify heterozygous mutation carriers at risk of having affected children. The Human Genetics Society of Australasia has produced a position statement with recommendations in relation to population-based screening for CF. These include: (1) that screening should be offered to all relatives of people with or carriers of CF (cascade testing) as well as to all couples planning to have children or who are pregnant; (2) the minimum CFTR mutation panel to be tested consists of 17 mutations which are those mutations that are associated with typical CF and occur with a frequency of 0.1% or higher among individuals diagnosed with CF in Australasia; (3) that genetic counselling is offered to all couples where both members are known to have one or two CFTR mutations and that such couples are given the opportunity to meet with a physician with expertise in the management of CF as well as a family/individual affected by the condition.

Next-generation carrier screening: are we ready?

Next-generation sequencing (NGS) methodology allows for a major expansion in current carrier screening tests. NGS testing has been shown to be analytically accurate and cost-effective, but major challenges include educational and counseling issues.