Benchmarks for Cystic Fibrosis carrier screening: A European consensus document

The new face of cystic fibrosis in the era of population genetic carrier screening

BACKGROUND

Population genetic carrier screening (PGCS) for cystic fibrosis (CF) has been offered to couples in Israel since 1999 and was included in a fully subsidized national program in 2008. We evaluated the impact of PGCS on CF incidence, genetic and clinical features.

METHODS

This was a retrospective national study. Demographic and clinical characteristics of children with CF born in Israel between 2008 and 2018 were obtained from the national CF registry and from patients' medical records. Data on CF births, preimplantation genetic testing (PGT), pregnancy termination and de-identified data from the PGCS program were collected.

RESULTS

CF births per 100,000 live births decreased from 8.29 in 2008 to 0.54 in 2018 (IRR = 0.84, p < 0.001). The CF pregnancy termination rate did not change (IRR = 1, p=  0.9) while the CF-related PGT rate increased markedly (IRR = 1.33, p < 0.001). One hundred and two children were born with CF between 2008 and 2018 with a median age at diagnosis of 4.8 months, range 0-111 months. Unlike the generally high uptake nationally, 65/102 had not performed PGCS. Even if all had utilized PGCS, only 51 would have been detected by the existing genetic screening panel. Clinically, 34 % of children were pancreatic sufficient compared to 23 % before 2008 (p = 0.04).

CONCLUSIONS

Since institution of a nationwide PGCS program, the birth of children with CF decreased markedly. Residual function variants and pancreatic sufficiency were more common. A broader genetic screening panel and increased PGCS utilization may further decrease the birth of children with CF.

Respiratory Infection and Inflammation in Cystic Fibrosis: A Dynamic Interplay among the Host, Microbes, and Environment for the Ages

The interplay between airway inflammation and infection is now recognized as a major factor in the pathobiology in cystic fibrosis (CF). A proinflammatory environment is seen throughout the CF airway resulting in classic marked and enduring neutrophilic infiltrations, irreversibly damaging the lung. Although this is seen to occur early, independent of infection, respiratory microbes arising at different timepoints in life and the world environment perpetuate this hyperinflammatory state. Several selective pressures have allowed for the CF gene to persist until today despite an early mortality. Comprehensive care systems, which have been a cornerstone of therapy for the past few decades, are now revolutionized by CF transmembrane conductance regulator (CTFR) modulators. The effects of these small-molecule agents cannot be overstated and can be seen as early as in utero. For an understanding of the future, this review looks into CF studies spanning the historical and present period.

The inequity of targeted cystic fibrosis reproductive carrier screening tests in Australia

OBJECTIVE

European and Australian guidelines for cystic fibrosis (CF) reproductive carrier screening recommend testing a small number of high frequency CF causing variants, rather than comprehensive CFTR sequencing. The study objective was to determine variant detection rates of commercially available targeted reproductive carrier screening tests in Australia.

METHODS

Next-generation DNA sequencing of the CFTR gene was performed on 2552 individuals from a whole population sample to identify CF causing variants. The variant detection rates of two commercially available Australian reproductive carrier screening tests, which target 50 or 175 CF causing variants, in this population were calculated. The ethnicity of individuals was determined using principal component analysis.

RESULTS

Variant detection rates of the tests for 50 and 175 CF causing variants were 88.2% and 90.8%, respectively. No CF causing variants in individuals of East Asian ethnicity (n = 3) were detected by either test, while >86.6% (n = 69) of CF causing variants in Europeans would be identified by either test.

CONCLUSIONS

Reproductive carrier screening tests for a targeted set of high frequency CF variants are unable to detect approximately 10% of CF variants in a multiethnic Australian population, and individuals of East Asian ethnicity are disproportionally affected by this test limitation.

Carrier detection probabilities for autosomal recessive variants in unrelated and consanguineous couples - an evaluation of the 86 genes of the ACMG 'Tier 3' panel

Carrier screening for autosomal recessive variants has become a cornerstone of community and public health genetics. While the first carrier screening programs were confined to conditions with relatively high prevalence, and hence well-known carrier frequency, the number of candidate genes has increased greatly since the advent of high-throughput DNA sequencing technologies. The epidemiological database of the ensuing gene panels is mostly sparse, and judgement of their performance is, therefore, anything but straightforward. We therefore derived estimates of the carrier detection probabilities among non-consanguineous and consanguineous couples as expected using the ‘Tier 3’ carrier screening gene panel recently recommended by the American College of Medical Genetics (ACMG). For non-Finnish Europeans, the respective estimate for unrelated couples equals 0.63%, implying that the ACMG Tier 3 panel accounts for over 90% of the genetic load for autosomal recessive diseases in this population. Among the offspring of first cousins, the corresponding incidence is expected to be tenfold higher, an increase still consistent with previous estimates of the overall risk of birth defects for this type of mating. Our considerations are intended to aid the implementation of carrier screening programs and to provide additional support to reproductive counselling and to obtaining informed consent.

Neglected impacts of patient decision-making associated with genetic testing

We highlight non-health-related impacts associated with genetic testing (GT) and knowing one’s genetic status so that health technology assessment (HTA) analysts and HTA audiences may more appropriately consider the pros and cons of GT. Whereas health-related impacts of GT (e.g., increased healthy behaviors and avoidance of harms of unnecessary treatment) are frequently assessed in HTA, some non-health-related impacts are less often considered and are more difficult to measure. This presents a challenge for accurately assessing whether a genetic test should be funded. In health systems where HTA understandably places emphasis on measurable clinical outcomes, there is a risk of creating a GT culture that is pro-testing without sufficient recognition of the burdens of GT. There is also a risk of not funding a genetic test that provides little clinical benefit but nonetheless may be seen by some as autonomy enhancing. The recent development of expanded HTA frameworks that include ethics analyses helps to address this gap in the evidence and bring awareness to non-health-related impacts of GT. The HTA analyst should be aware of these impacts, choose appropriate frameworks for assessing genetic tests, and use methods for evaluating impacts. A new reporting tool presented here may assist in such evaluations.

Preconception risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease

BACKGROUND

Globally, about 6% of children are born with a serious birth defect of genetic or partially genetic origin. Carrier screening or testing is one way to identify couples at increased risk of having a child with an autosomal recessive condition. The most common autosomal recessive conditions are thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease, with higher carrier rates in high-risk populations of specific ancestral backgrounds. Identifying and counselling couples at genetic risk of the conditions before pregnancy enables them to make fully informed reproductive decisions, with some of these choices not being available if testing is only offered in an antenatal setting. This is an update of a previously published review.

OBJECTIVES

To assess the effectiveness of systematic preconception genetic risk assessment to enable autonomous reproductive choice and to improve reproductive outcomes  in women and their partners who are both identified as carriers of thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease in healthcare settings when compared to usual care.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Registers. Date of latest search of the registers: 04 August 2021. In addition, we searched for all relevant trials from 1970 (or the date at which the database was first available if after 1970) to date using electronic databases (MEDLINE, Embase, CINAHL, PsycINFO), clinical trial databases (National Institutes of Health, Clinical Trials Search portal of the World Health Organization, metaRegister of controlled clinical trials), and hand searching of key journals and conference abstract books from 1998 to date (European Journal of Human Genetics, Genetics in Medicine, Journal of Community Genetics). We also searched the reference lists of relevant articles, reviews and guidelines and also contacted subject experts in the field to request any unpublished or other published trials. Date of latest search of all these sources: 25 June 2021.  SELECTION CRITERIA: Any randomised controlled trials (RCTs) or quasi-RCTs (published or unpublished) comparing reproductive outcomes of systematic preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease when compared to usual care.

DATA COLLECTION AND ANALYSIS

We identified 37 papers, describing 22 unique trials which were potentially eligible for inclusion in the review. However, after assessment, we found no RCTs of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease.

MAIN RESULTS

No RCTs of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease are included. A trial identified earlier has published its results and has subsequently been listed as excluded in this review.

AUTHORS' CONCLUSIONS

As there are no RCTs of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis, or Tay-Sachs disease included in either the earlier or current versions of this review, we recommend considering potential non-RCTs studies (for example prospective cohorts or before-and-after studies) for future reviews. While RCTs are desirable to inform evidence-based practice and robust recommendations, the ethical, legal and social implications associated with using this trial design to evaluate the implementation of preconception genetic risk assessment involving carrier testing and reproductive autonomy must also be considered.  In addition, rather than focusing on single gene-by-gene carrier testing for specific autosomal-recessive conditions as the intervention being evaluated, preconception expanded genetic screening should also be included in future searches as this has received much attention in recent years as a more pragmatic strategy. The research evidence for current international policy recommendations is limited to non-randomised studies.

Addressing the dark matter of gene therapy: technical and ethical barriers to clinical application

Gene therapies for genetic diseases have been sought for decades, and the relatively recent development of the CRISPR/Cas9 gene-editing system has encouraged a new wave of interest in the field. There have nonetheless been significant setbacks to gene therapy, including unintended biological consequences, ethical scandals, and death. The major focus of research has been on technological problems such as delivery, potential immune responses, and both on and off-target effects in an effort to avoid negative clinical outcomes. While the field has concentrated on how we can better achieve gene therapies and gene editing techniques, there has been less focus on when and why we should use such technology. Here we combine discussion of both the technical and ethical barriers to the widespread clinical application of gene therapy and gene editing, providing a resource for gene therapy experts and novices alike. We discuss ethical problems and solutions, using cystic fibrosis and beta-thalassemia as case studies where gene therapy might be suitable, and provide examples of situations where human germline gene editing may be ethically permissible. Using such examples, we propose criteria to guide researchers and clinicians in deciding whether or not to pursue gene therapy as a treatment. Finally, we summarize how current progress in the field adheres to principles of biomedical ethics and highlight how this approach might fall short of ethical rigour using examples in the bioethics literature. Ultimately by addressing both the technical and ethical aspects of gene therapy and editing, new frameworks can be developed for the fair application of these potentially life-saving treatments.

Factors influencing medical practitioner participation in population carrier screening for cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) carrier screening should be offered to people planning a pregnancy or in early pregnancy, according to current recommendations. However, research indicates rates of offering CF carrier screening are low. Health professionals (HPs) play an important role in offering population carrier screening.

AIMS

To determine the opinions, knowledge and practice patterns of HPs with regard to the routine offering of population carrier screening for CF.

MATERIALS AND METHODS

Five key informant interviews informed the development of an online questionnaire which was distributed to a select group of HPs involved in prenatal care in Victoria, Australia.

RESULTS

Of the participants who completed the questionnaire (n = 87), 35.6% reported offering CF carrier screening to all patients attending for preconception or early pregnancy consultations. High referrers of CF carrier screening were more likely to be female, work in the private sector, in metropolitan areas and specialise as an obstetrician. High referrers demonstrated a greater level of knowledge of CF and carrier screening than low referrers (t = -3.779, P < 0.001). Low referrers perceived more barriers to offering carrier screening than high referrers (t = 2.125, P = 0.037). Low referrers were more likely to perceive lack of community awareness and HP knowledge as a barrier to offering CF carrier screening, compared to high referrers, who were more likely to perceive time constraints as a barrier.

CONCLUSIONS

To promote routine offering of population CF carrier screening, resources are needed to improve knowledge and provide clinical support thereby reducing perceived barriers.

IVS8-5T Allele of CFTR is the Risk Factor in Chronic Pancreatitis, Especially in Idiopathic Chronic Pancreatitis

BACKGROUND

Cystic fibrosis transmembrane conductance regulator IVS8-5T gene variation appears to be associated with a higher risk of chronic pancreatitis (CP); however, there is inconsistency between previous reported studies. Here, we performed a meta-analysis to investigate this relationship.

MATERIALS AND METHODS

PubMed and WANFANG databases were searched for the case-control studies that contained Patients with CP with IVS8-5T variation. Odd ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relevance of IVS8-5T gene variation and CP.

RESULTS

Analysis showed that the frequency of the 5T allele was significantly higher in CP subjects than that in control subjects (OR = 1.43, 95% CI: 1.13-1.81, I² = 1.2%). Based on the subgroup analysis stratified by etiology, the 5T allele was associated with a higher risk of idiopathic chronic pancreatitis (ICP) (OR = 1.80, 95% CI: 1.18-2.76, I² = 0.0%) and not alcoholic CP (OR = 2.14, 95% CI: 0.98-4.66, I² = 0.0%). Further study indicated that the 5T allele was related to higher ICP prevalence in the European population (OR = 1.79, 95% CI: 1.06-3.03, I² = 0.0%). In contrast, there was no significant difference between ICP subjects and healthy controls within the Asian population (OR = 1.84, 95% CI: 0.91-3.72, I² = 38.0%).

CONCLUSIONS

Cystic fibrosis transmembrane conductance regulator IVS8-5T is a risk factor in patients with CP. IVS8-5T variation may play a significant role in the occurrence of ICP, especially in the European population.

Deciding on cystic fibrosis carrier screening: three citizens' juries and an online survey

Background

Health technology assessment and ethical issues have to be dealt with in deciding on national carrier screening for cystic fibrosis (CF)—the most frequent severe autosomal recessive disease in Caucasian populations and several stakeholders need to be involved. A citizens’ jury is one way to ask citizens to deliberate on controversial topics in the interests of a society. The aims of this project were to gather opinions about CF carrier screening through citizens' jury deliberations and to match them with the findings of a large online consultation survey open to the general population, people with CF and families and health professionals.

Methods

Three citizens’ juries and an online survey were asked: ‘Should the Health Service organize screening of the population with the aim of identifying healthy people who may have children with CF?’ The jurors had no medical background and no personal or family CF history. The survey was open to people with CF, families, and healthcare professionals.

Results

Jurors and survey respondents were in favour of CF carrier screening, mainly considering the severity of CF, the value of informed reproductive choices and the equality of the screening. All the citizens’ juries felt positively about the health service actively offer CF carrier screening to provide women and couples of reproductive age equal access and standardized information on the pros and cons.

Conclusion

Considering the favourable attitude towards CF screening, the feasibility of CF screening, in terms of best setting, target age and healthcare professionals providing it, should be tested in a clinical trial.

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.

Noninvasive paternal exclusion testing for cystic fibrosis in the first five to eight weeks of gestation

Prenatal genetic testing is not generally applicable to the very early stages of pregnancy (prior to week 8 gestation), a time period that is crucial to pregnant couples with high risk for transmission of genetic disease to their fetus. Therefore, we developed a new ultra-sensitive targeted next generation sequencing method for noninvasive haplotype-based paternal allele exclusion testing of the cystic fibrosis-associated gene, CFTR. This new method was compared to a conventional library prep and sequencing analysis method and all test results were validated by amniotic fluid testing at later stages of pregnancy. Out of 7 enrolled couples, who provided at least two blood samples (at least one week apart) for noninvasive CFTR testing, a result was obtained for 6 fetuses. Using the new hypersensitive method, all six couples (100%) received a correct diagnosis for the paternal allele as opposed to 3/6 (50%) when tested with the conventional strategy. Among 4 couples who provided just one early pregnancy blood draw for analysis, diagnosis was possible in one fetus, but only using the ultra-sensitive method. Thus, we describe a novel noninvasive CFTR screening method which demonstrates unprecedented fetal allele typing accuracy in the earliest stages of pregnancy.

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.

How do genetically disabled adults view selective reproduction? Impairment, identity, and genetic screening

Background

Genomic medicine is rapidly evolving, particularly in the domain of reproduction. Population carrier screening for a range of disorders is becoming possible using whole genome/exome sequencing. However, very little is known about the views of genetically disabled adults toward selective reproduction.

Methods

Forty‐three in‐depth qualitative interviews were carried out with adults living with different types of genetic condition, recruited through support groups and clinics. Interviews covered participants’ experiences of their condition and their views toward genetic intervention in reproduction. Thematic analysis of the data using NVivo 11 was undertaken, and participants were assigned categories as either supporting, not‐supporting, or having ambivalent views toward selective reproduction.

Results

The majority of participants (65%) expressed either disapproval of, or held ambivalent views toward, selective reproduction. Key reasons for non‐support included regarding genetic impairment as part of personal identity and the prioritization of social and environmental barrier removal. Key reasons for support of selective reproduction included negative and externalizing attitudes toward genetic impairment and a belief in the importance of informed reproductive decision‐making.

Conclusion

The degree to which participants identified with their impairment, more so than how they valued it, was significant in determining attitudes toward selective reproduction. Those who supported genetic screening viewed their impairment as separate to themselves, while participants who considered their impairment as integral to their identity were most likely to report ambivalent or negative attitudes. Policymakers and stakeholders considering the role of genetic carrier screening panels might usefully engage with adults affected by heritable disease as well as disability identity politics when considering the acceptability and social impact of genetic screening programs.

Preconception risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease

BACKGROUND

Globally, about five per cent of children are born with congenital or genetic disorders. The most common autosomal recessive conditions are thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease, with higher carrier rates in specific patient populations. Identifying and counselling couples at genetic risk of the conditions before pregnancy enables them to make fully informed reproductive decisions, with some of these choices not being available if genetic counselling is only offered in an antenatal setting. This is an update of a previously published review.

OBJECTIVES

To assess the effectiveness of systematic preconception genetic risk assessment to improve reproductive outcomes in women and their partners who are identified as carriers of thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease in healthcare settings when compared to usual care.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Registers. In addition, we searched for all relevant trials from 1970 (or the date at which the database was first available if after 1970) to date using electronic databases (MEDLINE, Embase, CINAHL, PsycINFO), clinical trial databases (National Institutes of Health, Clinical Trials Search portal of the World Health Organization, metaRegister of controlled clinical trials), and hand searching of key journals and conference abstract books from 1998 to date (European Journal of Human Genetics, Genetics in Medicine, Journal of Community Genetics). We also searched the reference lists of relevant articles, reviews and guidelines and also contacted subject experts in the field to request any unpublished or other published trials.Date of latest search of the registers: 20 June 2017.Date of latest search of all other sources: 16 November 2017.

SELECTION CRITERIA

Any randomised or quasi-randomised controlled trials (published or unpublished) comparing reproductive outcomes of systematic preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease when compared to usual care.

DATA COLLECTION AND ANALYSIS

We identified 25 papers, describing 16 unique trials which were potentially eligible for inclusion in the review. However, after assessment, no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were found.

MAIN RESULTS

No randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were included. One ongoing trial has been identified which may potentially eligible for inclusion once completed.

AUTHORS' CONCLUSIONS

As no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis, or Tay-Sachs disease were found for inclusion in this review, the research evidence for current policy recommendations is limited to non-randomised studies.Information from well-designed, adequately powered, randomised trials is desirable in order to make more robust recommendations for practice. However, such trials must also consider the legal, ethical, and cultural barriers to implementation of preconception genetic risk assessment.

Cystic fibrosis carriership and tuberculosis: hints toward an evolutionary selective advantage based on data from the Brazilian territory

Background

The reason why Cystic Fibrosis (CF) is the most common fatal genetic disease among Caucasians has been incompletely studied. We aimed at deepening the hypothesis that CF carriers have a relative protection against Mycobacterium tuberculosis (Mtb) infection.

Methods

Applying spatial epidemiology, we studied the link between CF carriership rate and tuberculosis (TB) incidence in Brazil. We corrected for 5 potential environmental and 2 immunological confounders in this relation: monthly income, sanitary provisions, literacy rates, racial composition and population density along with AIDS incidence rates and diabetes mellitus type 2. Smoking data were incomplete and not available for analysis.

Results

A significant, negative correlation between CF carriership rate and TB incidence, independent of any of the seven confounders was found.

Conclusion

We provide exploratory support for the hypothesis that carrying a single CFTR mutation arms against Mtb infections.

Preconception and prenatal genetic counselling

Identifying individuals at risk of having children affected by genetic conditions or congenital anomalies allows counselling that aims to inform reproductive decisions. This process takes place either at the preconception or early prenatal stage, although more options are available if risks are identified before the pregnancy. Preconception counselling covers issues that can affect the health of the mother and baby including folic acid supplementation. Carrier screening for autosomal recessive diseases, such as beta thalassaemia, has resulted in a significantly reduced incidence in many countries. National organisations, however, advocate more in-depth research before such screening recommendations apply to the general population. Recently, advances in genomic technologies have made it possible to greatly expand the scope of genetic screening, with the aim of providing more comprehensive information to prospective parents. This is a complex field, and research should focus on how the technology can be put to best use in the future.

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.

Nationwide genetic analysis for molecularly unresolved cystic fibrosis patients in a multiethnic society: implications for preconception carrier screening

Background

Preconception carrier screening for cystic fibrosis (CF) is usually performed using ethnically targeted panels of selected mutations. This has been recently challenged by the use of expanded, ethnically indifferent, pan‐population panels. Israel is characterized by genetically heterogeneous populations carrying a wide range of CFTR mutations. To assess the potential of expanding the current Israeli preconception screening program, we sought the subset of molecularly unresolved CF patients listed in the Israeli CF data registry comprising ~650 patients.

Methods

An Israeli nationwide genotyping of 152 CF cases, representing 176 patients lacking molecular diagnosis, was conducted. Molecular analysis included Sanger sequencing for all exons and splice sites, multiplex ligation probe amplification (MLPA), and next‐generation sequencing of the poly‐T/TG tracts.

Results

We identified 54 different mutations, of which only 16 overlapped the 22 mutations included in the Israeli preconception screening program. A total of 29/54 (53.7%) mutations were already listed as CF causing by the CFTR2 database, and only 4/54 (7.4%) were novel. Molecular diagnosis was reached in 78/152 (51.3%) cases. Prenatal diagnosis of 24/78 (30.8%) cases could have been achieved by including all CFTR2‐causing mutations in the Israeli panel.

Conclusions

Our data reveal an overwhelming hidden abundance of CFTR gene mutations suggesting that expanded preconception carrier screening might achieve higher preconception detection rates.

Diagnosis of Cystic Fibrosis in Screened Populations

OBJECTIVE

Cystic fibrosis (CF) can be difficult to diagnose, even when newborn screening (NBS) tests yield positive results. This challenge is exacerbated by the multitude of NBS protocols, misunderstandings about screening vs diagnostic tests, and the lack of guidelines for presumptive diagnoses. There is also confusion regarding the designation of age at diagnosis.

STUDY DESIGN

To improve diagnosis and achieve standardization in definitions worldwide, the CF Foundation convened a committee of 32 experts with a mission to develop clear and actionable consensus guidelines on diagnosis of CF with an emphasis on screened populations, especially the newborn population. A comprehensive literature review was performed with emphasis on relevant articles published during the past decade.

RESULTS

After reviewing the common screening protocols and outcome scenarios, 14 of 27 consensus statements were drafted that apply to screened populations. These were approved by 80% or more of the participants.

CONCLUSIONS

It is recommended that all diagnoses be established by demonstrating dysfunction of the CF transmembrane conductance regulator (CFTR) channel, initially with a sweat chloride test and, when needed, potentially with newer methods assessing membrane transport directly, such as intestinal current measurements. Even in babies with 2 CF-causing mutations detected via NBS, diagnosis must be confirmed by demonstrating CFTR dysfunction. The committee also recommends that the latest classifications identified in the Clinical and Functional Translation of CFTR project [http://www.cftr2.org/index.php] should be used to aid with CF diagnosis. Finally, to avoid delays in treatment, we provide guidelines for presumptive diagnoses and recommend how to determine the age of diagnosis.

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.

Cystic Fibrosis Diagnosis and Newborn Screening

The diagnosis of cystic fibrosis (CF) has evolved over the past decade as newborn screening has become universal in the United States and elsewhere. The heterogeneity of phenotypes associated with CF transmembrane conductance regulator (CFTR) dysfunction and mutations in the CFTR gene has become clearer, ranging from classic pancreatic-insufficient CF to manifestations in only 1 organ system to indeterminate diagnoses identified by newborn screening. The tools available for diagnosis have also expanded. This article reviews the newest diagnostic criteria for CF, newborn screening, prenatal screening and diagnosis, and indeterminate diagnoses in newborn-screened infants and symptomatic adults.

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.

Swedish healthcare providers' perceptions of preconception expanded carrier screening (ECS)-a qualitative study

Reproductive autonomy, medicalization, and discrimination against disabled and parental responsibility are the main ongoing ethical debates concerning reproductive genetic screening. To examine Swedish healthcare professionals' views on preconception expanded carrier screening (ECS), a qualitative study involving academic and clinical institutions in Sweden was conducted in September 2014 to February 2015. Eleven healthcare professionals including clinicians, geneticists, a midwife, and a genetic counselor were interviewed in depth using a semi-structured interview guide. The questionnaire was constructed after reviewing the main literature and meetings with relevant healthcare providers. The interviews were recorded, transcribed verbatim, and content analyzed for categories and subcategories. Participants nurtured many ethical and non-ethical concerns regarding preconception ECS. Among the ethical concerns were the potential for discrimination, medicalization, concerns with prioritization of healthcare resources, and effects on reproductive freedom. The effects of implementation of preconception ECS, its stakeholders, regulations, and motivation are some of non-ethical concerns. These concerns, if not addressed, may affect the uptake and usage of carrier screening within Swedish healthcare system. As this is a qualitative study with a small non-random sample size, the findings cannot be generalized. The participants had little to no working experience with expanded screening panels. Moreover, the interviews were conducted in English, a second language for the participants, which might have limited the expression of their views. However, the authors claim that the findings may be pertinent to similar settings in other Scandinavian countries.

Cystic Fibrosis: A Review of Associated Phenotypes, Use of Molecular Diagnostic Approaches, Genetic Characteristics, Progress, and Dilemmas

Cystic fibrosis (CF) is an autosomal recessive disease with significant associated morbidity and mortality. It is now appreciated that the broad phenotypic CF spectrum is not explained by obvious genotype-phenotype correlations, suggesting that CF transmembrane conductance regulator (CFTR)-related disease may occur because of multiple additive effects. These contributing effects include complex CFTR alleles, modifier genes, mutations in alternative genes that produce CF-like phenotypes, epigenetic factors, and environmental influences. Most patients in the United States are now diagnosed through newborn screening and use of molecular testing methods. We review the molecular testing approaches and laboratory guidelines for carrier screening, prenatal testing, newborn screening, and clinical diagnostic testing, as well as recent developments in CF treatment, and reasons for the lack of a molecular diagnosis in some patients.

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.

Preconception risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease

BACKGROUND

Globally, about five per cent of children are born with congenital or genetic disorders. The most common autosomal recessive conditions are thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease, with higher carrier rates in specific patient populations. Identifying and counselling couples at genetic risk of the conditions before pregnancy enables them to make fully informed reproductive decisions, with some of these choices not being available if genetic counselling is only offered in an antenatal setting.

OBJECTIVES

To assess the effectiveness of systematic preconception genetic risk assessment to improve reproductive outcomes in women and their partners who are identified as carriers of thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease in healthcare settings when compared to usual care.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Registers. In addition, we searched for all relevant trials from 1970 (or the date at which the database was first available if after 1970) to date using electronic databases (MEDLINE, Embase, CINAHL, PsycINFO), clinical trial databases (National Institutes of Health, Clinical Trials Search portal of the World Health Organization, metaRegister of controlled clinical trials), and hand searching of key journals and conference abstract books from 1998 to date (European Journal of Human Genetics, Genetics in Medicine, Journal of Community Genetics). We also searched the reference lists of relevant articles, reviews and guidelines and also contacted subject experts in the field to request any unpublished or other published trials.Date of latest search of the registers: 25 June 2015.Date of latest search of all other sources: 10 December 2014.

SELECTION CRITERIA

Any randomised or quasi-randomised control trials (published or unpublished) comparing reproductive outcomes of systematic preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease when compared to usual care.

DATA COLLECTION AND ANALYSIS

We identified 19 papers, describing 13 unique trials which were potentially eligible for inclusion in the review. However, after assessment, no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were found.

MAIN RESULTS

No randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were found.

AUTHORS' CONCLUSIONS

As no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis, or Tay-Sachs disease were found for inclusion in this review, the research evidence for current policy recommendations is limited to non-randomised studies.Information from well-designed, adequately powered, randomised trials is desirable in order to make more robust recommendations for practice. However, such trials must also consider the legal, ethical, and cultural barriers to implementation of preconception genetic risk assessment.

Attitudes of cystic fibrosis patients and parents toward carrier screening and related reproductive issues

Cystic fibrosis (CF) is a life-limiting autosomal recessive disorder affecting ~1 in 2500-4000 Caucasians. As most CF patients have no family history of the disorder, carrier screening for CF has the potential to prospectively identify couples at risk of conceiving an affected child. At-risk couples may consequently choose to act on the provided information and take steps to avoid the birth of a child with CF. Although carrier screening is widely believed to enhance reproductive autonomy of prospective parents, the practice also raises important ethical questions. A written questionnaire was administered to adult patients and parents of children with CF with the aim to explore participants' attitudes toward CF carrier screening and related reproductive issues. The study population was recruited from a CF patient registry in Belgium and comprised 111 participants (64 parents, 47 patients aged 16 or older). We found that more than 80% of all participants were in favor of preconception carrier screening for CF. However, some were concerned over potential negative consequences of population-wide CF carrier screening. Regarding future reproductive intentions, 43% of the participants indicated a desire to have children. Among these, preimplantation genetic diagnosis was found to be the most preferred reproductive option, closely followed by spontaneous pregnancy and prenatal diagnosis. Although the findings of our study suggest that patients and parents of children with CF support a population-based carrier screening program for CF, they also highlight some issues deserving particular attention when implementing such a program.

Targeted carrier screening for four recessive disorders: high detection rate within a founder population

In a genetically isolated community in the Netherlands four severe recessive genetic disorders occur at relatively high frequency (pontocerebellar hypoplasia type 2 (PCH2), fetal akinesia deformation sequence (FADS), rhizomelic chondrodysplasia punctata type 1 (RCDP1), and osteogenesis imperfecta (OI) type IIB/III. Over the past decades multiple patients with these disorders have been identified. This warranted the start of a preconception outpatient clinic, in 2012, aimed at couples planning a pregnancy. The aim of our study was to evaluate the offer of targeted genetic carrier screening as a method to identify high-risk couples for having affected offspring in this high-risk subpopulation. In one year, 203 individuals (92 couples and 19 individuals) were counseled. In total, 65 of 196 (33.2%) tested individuals were carriers of at least one disease, five (7.7%) of them being carriers of two diseases. Carrier frequencies of PCH2, FADS, RCDP1, and OI were 14.3%, 11.2%, 6.1%, and 4.1% respectively. In individuals with a positive family history for one of the diseases, the carrier frequency was 57.8%; for those with a negative family history this was 25.8%. Four PCH2 carrier-couples were identified. Thus, targeted (preconception) carrier screening in this genetically isolated population in which a high prevalence of specific disorders occurs detects a high number of carriers, and is likely to be more effective compared to cascade genetic testing. Our findings and set-up can be seen as a model for carrier screening in other high-risk subpopulations and contributes to the discussion about the way carrier screening can be offered and organized in the general population.

European Cystic Fibrosis Society Standards of Care: Best Practice guidelines

Specialised CF care has led to a dramatic improvement in survival in CF: in the last four decades, well above what was seen in the general population over the same period. With the implementation of newborn screening in many European countries, centres are increasingly caring for a cohort of patients who have minimal lung disease at diagnosis and therefore have the potential to enjoy an excellent quality of life and an even greater life expectancy than was seen previously. To allow high quality care to be delivered throughout Europe, a landmark document was published in 2005 that sets standards of care. Our current document builds on this work, setting standards for best practice in key aspects of CF care. The objective of our document is to give a broad overview of the standards expected for screening, diagnosis, pre-emptive treatment of lung disease, nutrition, complications, transplant/end of life care and psychological support. For comprehensive details of clinical care of CF, references to the most up to date European Consensus Statements, Guidelines or Position Papers are provided in Table 1. We hope that this best practice document will be useful to clinical teams both in countries where CF care is developing and those with established CF centres.

Differences in immunoreactive trypsin values between type of feeding and ethnicity in neonatal cystic fibrosis screening: a cross-sectional study

BACKGROUND

We studied the differences in immunoreactive trypsin (IRT) in neonatal screening for cystic fibrosis (CF) associated individually with the age of the newborn, ethnicity and environmental temperature. In this study, we determine the overall influence of environmental temperature at birth, gender, feeding, gestational age, maternal age and ethnic origin on an abnormal IRT result.

METHODS

Cross-sectional observational study. A sample was selected of newborns from Alicante (Spain) who underwent neonatal CF screening in 2012-2013. Primary variable: abnormal IRT levels (≥65 ng/ml). Secondary variables: gender, maternal origin, maternal age (years) (<20, 20-40, >40), gestational age (weeks) (<32, 32-37, >37), type of feeding (natural, formula, mixed and special nutrition), >20 days from birth to blood collection, and average temperature during the month of birth (in°C). Using a multivariate logistic regression model the adjusted odds ratios (ORs) were estimated to analyze the association between atypical IRT levels and the study variables. The α error was 5% and confidence intervals (CI) were calculated for the most relevant parameters.

RESULTS

Of a total of 13,310 samples, 199 were abnormal (1.34%). Significant associated factors: feeding method (natural → OR = 1; mixed → OR = 0.53, 95% CI: 0.31-0.89; formula → OR = 0.72, 95% CI: 0.48-1.07; special → OR = 21.88, 95% CI: 6.92-69.14; p < 0.001).

CONCLUSIONS

Newborns receiving special nutrition have a 20-fold higher risk for abnormal IRT levels, and screening is advisable once normalized feeding is initiated. It is advisable to consider ethnic variability. Seasonality was not important.

Prenatal and preconception population carrier screening for cystic fibrosis in Australia: where are we up to?

AIMS

To describe prenatal and preconception population carrier screening for cystic fibrosis (CF) in Australia and consider progress towards establishing a universal program.

METHOD

Medline and Embase databases (1989-2013) were searched for all publications with Australian data. Existing programs for CF carrier screening in Australia were reviewed and professional peak body websites accessed to determine recommendations.

RESULTS

Twenty-two studies met the inclusion criteria. Key stakeholder groups believe that prenatal and preconception carrier screening for CF should be available. Health-economic analyses support that CF carrier screening can be cost-effective. There are small programs for CF carrier screening, in Victoria, New South Wales and Queensland. The Human Genetics Society of Australasia (HGSA) specifically recommend that screening be offered to women and couples planning a pregnancy and in the early stages of pregnancy. Other peak bodies indirectly endorse the availability of CF carrier screening. Barriers to screening include not being offered screening, the cost of testing, inequity of access and an incorrect perception that not having a family history of CF lowers risk.

CONCLUSIONS

There is support for prenatal and preconception CF carrier screening by the community, health professionals and peak professional bodies in Australia. The barriers to development of a national screening program could be overcome with greater physician engagement and government support.

IMPLICATIONS

In the interest of equity, government funded testing should be routinely offered to all pregnant women and couples planning a pregnancy.

Analysis of cystic fibrosis gene mutations in children with cystic fibrosis and in 964 infertile couples within the region of Basilicata, Italy: a research study

INTRODUCTION

Cystic fibrosis is the most common autosomal recessive genetic disease in the Caucasian population. Extending knowledge about the molecular pathology on the one hand allows better delineation of the mutations in the CFTR gene and the other to dramatically increase the predictive power of molecular testing.

METHODS

This study reports the results of a molecular screening of cystic fibrosis using DNA samples of patients enrolled from January 2009 to December 2013. Patients were referred to our laboratory for cystic fibrosis screening for infertile couples. In addition, we identified the gene mutations present in 76 patients affected by cystic fibrosis in the pediatric population of Basilicata.

RESULTS

In the 964 infertile couples examined, 132 subjects (69 women and 63 men) resulted heterozygous for one of the CFTR mutations, with a recurrence of carriers of 6.85%. The recurrence of carriers in infertile couples is significantly higher from the hypothetical value of the general population (4%).

CONCLUSIONS

This study shows that in the Basilicata region of Italy the CFTR phenotype is caused by a small number of mutations. Our aim is to develop a kit able to detect not less than 96% of CTFR gene mutations so that the relative risk for screened couples is superimposable with respect to the general population.

Cystic fibrosis: to screen or not to screen? Involving a Citizens' jury in decisions on screening carrier

Context

In recent years, the continuous improvements in molecular biology techniques have made it possible to detect carriers for several genetic conditions, including cystic fibrosis (CF). In some countries, CF carrier screening is offered to increasing subset of the general population.

Offering of carrier screening at a population level should not be decided by local health authorities only, without consulting citizens' preferences. One way to involve citizens in the decision process might be to a Citizens' jury, a method of deliberative democracy.

Objective

The object of the study is to produce a recommendation statement about CF carrier screening using a Citizens' jury. As this is a new method in the field, the study also provided the opportunity to evaluate its effectiveness.

Design

The project is designed and managed by an executive committee. The whole process is superintended by a multidisciplinary scientific committee. The 16 members of the jury attend a 1 day meeting, assisted by a non‐medical and unbiased facilitator. Informative material was prepared and distributed 15 days before the jury meeting; during the meeting, experts and witnesses interact directly with all the jurors through questions and answers.

Results

All except one member of the jury felt positively about the Health Service actively providing population carrier screening for CF. The final statement was available to public, clinicians, researchers and decision‐makers.

Discussion

In general, a Citizens' jury is a feasible method for involving citizens in public health decision‐making process and in particular for obtaining a community view about CF carrier screening.

Cystic fibrosis carrier screening

Carrier screening for cystic fibrosis (CF) has been available since the early 1990s, yet there are few programs, and none funded as part of a national health care strategy. The aim of this paper is to provide a description of carrier screening for CF and examine the progress that has been made towards the establishment of universal population-based carrier screening programs. This is an evidence based commentary on population-based carrier screening for CF. Peak body recommendations were examined and existing programs for CF carrier screening are reviewed. The attitudes from the non-CF community, CF healthcare professionals and people with CF were studied. Data from health economic assessments is examined. The future of carrier screening for CF in the context of advancing genetic technologies and potentially curative therapies is considered.

Current issues in medically assisted reproduction and genetics in Europe: research, clinical practice, ethics, legal issues and policy. European Society of Human Genetics and European Society of Human Reproduction and Embryology

In March 2005, a group of experts from the European Society of Human Genetics and European Society of Human Reproduction and Embryology met to discuss the interface between genetics and assisted reproductive technology (ART), and published an extended background paper, recommendations and two Editorials. Seven years later, in March 2012, a follow-up interdisciplinary workshop was held, involving representatives of both professional societies, including experts from the European Union Eurogentest2 Coordination Action Project. The main goal of this meeting was to discuss developments at the interface between clinical genetics and ARTs. As more genetic causes of reproductive failure are now recognised and an increasing number of patients undergo testing of their genome before conception, either in regular health care or in the context of direct-to-consumer testing, the need for genetic counselling and preimplantation genetic diagnosis (PGD) may increase. Preimplantation genetic screening (PGS) thus far does not have evidence from randomised clinical trials to substantiate that the technique is both effective and efficient. Whole-genome sequencing may create greater challenges both in the technological and interpretational domains, and requires further reflection about the ethics of genetic testing in ART and PGD/PGS. Diagnostic laboratories should be reporting their results according to internationally accepted accreditation standards (International Standards Organisation - ISO 15189). Further studies are needed in order to address issues related to the impact of ART on epigenetic reprogramming of the early embryo. The legal landscape regarding assisted reproduction is evolving but still remains very heterogeneous and often contradictory. The lack of legal harmonisation and uneven access to infertility treatment and PGD/PGS fosters considerable cross-border reproductive care in Europe and beyond. The aim of this paper is to complement previous publications and provide an update of selected topics that have evolved since 2005.

CFTR protein repair therapy in cystic fibrosis

Cystic fibrosis is a single gene, autosomal recessive disorder, in which more than 1,900 mutations grouped into 6 classes have been described. It is an example a disease that could be well placed to benefit from personalised medicine. There are currently 2 very different approaches that aim to correct the basic defect: gene therapy, aimed at correcting the genetic alteration, and therapy aimed at correcting the defect in the CFTR protein. The latter is beginning to show promising results, with several molecules under development. Ataluren (PTC124) is a molecule designed to make the ribosomes become less sensitive to the premature stop codons responsible for class i mutations. Lumacaftor (VX-809) is a CFTR corrector directed at class ii mutations, among which Phe508del is the most frequent, with encouraging results. Ivacaftor (VX-770) is a potentiator, the only one marketed to date, which has shown good efficacy for the class iii mutation Gly551Asp in children over the age of 6 and adults. These drugs, or a combination of them, are currently undergoing various clinical trials for other less common genetic mutations. In the last 5 years, CFTR has been designated as a therapeutic target. Ivacaftor is the first drug to treat the basic defect in cystic fibrosis, but only provides a response in a small number of patients. New drugs capable of restoring the CFTR protein damaged by the most common mutations are required.

Screening for cystic fibrosis: what every NP should know

In a chronic childhood disease such as cystic fibrosis, it is important for nurse practitioners to be knowledgeable about the disease process, methods of mutation identification, and diagnostic criteria. Multiple studies have shown improved prognosis for patients diagnosed early.

CFTR2: How will it help care?

The Clinical and Functional Translation of CFTR (CFTR2) project presents a novel approach to clinical and functional annotation of mutations identified in disease-causing genes. Phenotype and genotype information on approximately 40,000 cystic fibrosis (CF) patients were collected from registries and large clinics. The disease-liability of the 160 most frequently reported mutations was evaluated by means of a multistage process which involved clinical (sweat chloride average), functional (expression in cell-based systems) and epidemiological (mutation analysis in obligate heterozygotes) steps. The results of this analysis can be consulted in a dedicated website. Data originated by CFTR2 may be valuable in several facets of CF care, including diagnosis, newborn screening, carrier testing, genotype/phenotype correlation and mutation-specific therapeutics.

Attitudes of health care professionals toward carrier screening for cystic fibrosis. A review of the literature

Recent technological developments in molecular genetics facilitate the large-scale detection of inherited genetic disorders and allow an increasing number of genetic conditions to be screened for (American College of Medical Genetics 2012). This technological evolution creates the background which makes reflection necessary about the desirability to offer community-based (preconception) carrier screening in the healthcare system. A positive attitude of potential providers is vital to the success of a screening program. Therefore, the objective of this article is to elaborate a review of the attitudes of healthcare professionals toward carrier screening. Examination of existing carrier screening programs could provide such information. The literature review will be focused on the attitudes toward carrier screening for cystic fibrosis (CF). The databases Pubmed and Web of Science, as well as the interface Google Scholar, were searched using the keywords for the period 1990-2011. Studies were selected if they were published in a peer-reviewed journal in English and described the attitudes of potential providers toward carrier screening. Eleven studies were retrieved describing the attitudes toward carrier screening for CF. In total, seven studies reported attitudes toward the best time for carrier screening; four studies described opinions toward the best setting to offer CF carrier screening; six studies investigated the willingness to be involved in a carrier screening program, and in total 11 articles reported the concerns about offering carrier screening. Ten papers described a general attitude toward carrier screening. We can conclude that health care providers state willingness to be involved in a carrier screening program, but there is need for appropriate education as well as adequate support given the time constraints already present in consultation. The prospect of an increasing number of genetic disorders for which screening becomes possible, and the potential increasing demand for such screening in the future calls for the need for further debate on the desirability of carrier screening and relevant questions such as the conditions screened, the providers involved, the information provision, and counseling.

Preconception care and genetic risk: ethical issues

Preconception care to address genetic risks in reproduction may be offered either individually to couples with a known or suspected increased risk of having a child with a genetic disorder, or systematically to couples or individuals of reproductive age. The identification of couples at risk of transmitting a (serious) genetic disorder allows those couples to refrain from having children or to adapt their reproductive plans (using prenatal or preimplantation diagnosis, donor gametes, or adoption). Ethical issues concern the possible objectives of providing these options through preconception genetic counseling or screening, objections to abortion and embryo-selection, concerns about eugenics and medicalization, and issues arising in the professional–client relationship and/or in the light of the normative framework for population screening. Although enhancing reproductive autonomy rather than prevention should be regarded as the primary aim of preconception care for genetic risks, directive counseling may well be acceptable in exceptional cases, and prevention in the sense of avoiding serious suffering may be an appropriate objective of specific community-based preconception screening programmes. The seemingly unavoidable prospect of comprehensive preconception screening raises further ethical issues.