Neonatal screening for cystic fibrosis in Brittany, France: assessment of 10 years' experience and impact on prenatal diagnosis

Prenatal Diagnosis of Cystic Fibrosis by Celocentesis

Celocentesis is a new sampling tool for prenatal diagnosis available from 7 weeks in case of couples at risk for genetic diseases. In this study, we reported the feasibility of earlier prenatal diagnosis by celocentesis in four cases of cystic fibrosis and one case of cystic fibrosis and β-thalassemia co-inherited in the same fetus. Celomic fluids were aspired from the celomic cavity between 8+2 and 9+3 weeks of gestation and fetal cells were picked up by micromanipulator. Maternal DNA contamination was tested and target regions of fetal DNA containing parental pathogenetic variants of CFTR and HBB genes were amplified and sequenced. Four of the five fetuses resulted as being affected by cystic fibrosis and, in all cases, the women decided to interrupt the pregnancy. In the other case, the fetus presented a healthy carrier of cystic fibrosis. The results were confirmed in three cases on placental tissue. In one case, no abortive tissue was obtained. In the last case, the woman refused the prenatal diagnosis to confirm the celocentesis data; the pregnancy is ongoing without complications. This procedure provides prenatal diagnosis of monogenic diseases at least four weeks earlier than traditional procedures, reducing the anxiety of patients and providing the option for medical termination of the affected fetus at 8-10 weeks of gestation, which is less traumatic and safer than surgical termination in the second trimester.

A novel in vitro model to study prolonged Pseudomonas aeruginosa infection in the cystic fibrosis bronchial epithelium

Pseudomonas aeruginosa (PA) is known to chronically infect airways of people with cystic fibrosis (CF) by early adulthood. PA infections can lead to increased airway inflammation and lung tissue damage, ultimately contributing to decreased lung function and quality of life. Existing models of PA infection in vitro commonly utilize 1-6-hour time courses. However, these relatively early time points may not encompass downstream airway cell signaling in response to the chronic PA infections observed in people with cystic fibrosis. To fill this gap in knowledge, the aim of this study was to establish an in vitro model that allows for PA infection of CF bronchial epithelial cells, cultured at the air liquid interface, for 24 hours. Our model shows with an inoculum of 2 x 102 CFUs of PA for 24 hours pro-inflammatory markers such as interleukin 6 and interleukin 8 are upregulated with little decrease in CF bronchial epithelial cell survival or monolayer confluency. Additionally, immunoblotting for phosphorylated phospholipase C gamma, a well-known downstream protein of fibroblast growth factor receptor signaling, showed significantly elevated levels after 24 hours with PA infection that were not seen at earlier timepoints. Finally, inhibition of phospholipase C shows significant downregulation of interleukin 8. Our data suggest that this newly developed in vitro "prolonged PA infection model" recapitulates the elevated inflammatory markers observed in CF, without compromising cell survival. This extended period of PA growth on CF bronchial epithelial cells will have impact on further studies of cell signaling and microbiological studies that were not possible in previous models using shorter PA exposures.

Psychosocial Issues Related to Newborn Screening: A Systematic Review and Synthesis

Genomic advances have contributed to a proliferation of newborn screening (NBS) programs. Psychosocial consequences of NBS have been identified as risks to these public health initiatives. Following PRISMA guidelines, this systematic review synthesizes findings from 92 evidence-based, peer-reviewed research reports published from 2000 through 2020 regarding psychosocial issues associated with NBS. Results describe parents' knowledge of and attitudes towards NBS, reactions to and understanding of positive NBS results, experiences of communication with health providers, decisions about carrier testing, and future pregnancies. Findings also explain the impact of positive NBS results on parent-child relationships, child development, informing children about carrier status, family burden, quality of life, and disparities. In conclusion, psychosocial consequences of receiving unexpected neonatal screening results and unsolicited genetic information remain significant risks to expansion of NBS. Findings suggest that risks may be mitigated by improved parent NBS education, effective communication, individualized genetic counseling, and anticipatory developmental guidance. Clinicians need to take extra measures to ensure equitable service delivery to marginalized subpopulations. Future investigations should be more inclusive of culturally and socioeconomically diverse families and conducted in low-resource countries. Providing these countries with adequate resources to develop NBS programs is an essential step towards achieving international health equity.

[Cystic fibrosis: From gene discovery to precision medicine]

The discovery in 1989 that cystic fibrosis, the most common life-shortening hereditary disease in Caucasians, was caused by mutations in cystic fibrosis transmembrane conductance regulator (CFTR) gene, put in motion whole new areas of research, diagnosis, and therapeutic development. In this review, we focus on the most important advances in our understanding of the molecular basis of CFTR dysfunction. To date, over 2,000 CFTR mutations belonging to six protein-defect classes have been identified, increasing vastly our understanding of genotype/phenotype correlations. In the last 30 years, major achievements have been made in neonatal screening, antenatal diagnosis, and crucially with recent breakthroughs in the development of CFTR-directed therapies that may be effective for 90% of patients, paving the way for precision medicine.

Comparison between two newborn screening strategies for cystic fibrosis in Argentina: IRT/IRT versus IRT/PAP

BACKGROUND

The benefits of early cystic fibrosis (CF) detection using newborn screening (NBS) has led to widespread use in NBS programs. Since 2002, a two-stage immunoreactive trypsinogen (IRT/IRT) screening strategy has been used as a CFNBS method in all public maternity units in the City of Buenos Aires, Argentina. However, novel screening strategies may be more efficient. The aim of this study is to prospectively compare two CFNBS strategies: IRT/IRT and IRT/PAP (pancreatitis-associated protein).

METHODS

A two-year prospective study was performed. IRT was measured in dried blood samples collected 48-72 h after birth. When an IRT value was abnormal, PAP was determined, and a second visit was scheduled to obtain another sample for IRT before 25 days of life. Newborns with a positive CFNBS were referred for a confirmatory sweat test.

RESULTS

There were 69,827 births in the City of Buenos Aires during the period studied; 918 (1.31%) had an abnormal IRT. A total of 207 children (22.5%) failed to return for the second IRT, but only two PAP (0.2%) were not performed. IRT/IRT was more likely to lead to a referral for sweat testing than IRT/PAP (odds ratio 2.3 [95% confidence interval 1.8-2.9], p < .001). Sensitivity and specificity were: 80% and 100% and 86.5% and 82.6% for IRT/IRT and IRT/PAP strategies, respectively.

CONCLUSION

The IRT/PAP strategy is more sensitive than IRT/IRT and has similar specificity; it avoids a second visit and unnecessary sweat testing, and it reduces loss to follow-up in our population.

Newborn screening for CF in France: An exemplary national experience

Newborn screening (NBS) for cystic fibrosis (CF) was implemented throughout France since 2002, with a 3-tiered strategy consisting in an immunoreactive trypsinogen (IRT) measurement at day-3, a search for the most common mutations responsible for CF when the IRT value is above the cut-off level, and, if necessary, a safetynet retesting of IRT at day-21. Coordination and follow-up are ensured at the national level and NBS is carried out through a regional organization involving NBS centers, biochemical and molecular genetics laboratories. Sweat testing and comprehensive mutation gene analysis are then performed according to a defined algorithm. Between 2002 and 2014, screening for the 30 most common mutations identified 87% of the alleles and comprehensive mutation gene analysis performed when applicable identified more than 300 additional mutations and resulted in a detection rate of 99.8% of the mutated alleles. Program surveillance ensured at a national level allowed to carry out adaptation of cut-off levels and removal of the p.Arg117His mutation. Thanks to these modifications, the performance of the French NBS program for CF meets the European guideline standards regarding positive predictive values, sensitivity and time to initial visit at the CF center, thus making the strategy effective. © 2020 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.

The Changing Epidemiology of Cystic Fibrosis: Incidence, Survival and Impact of the CFTR Gene Discovery

Significant advances in the management of cystic fibrosis (CF) in recentdecades have dramatically changed the epidemiology and prognosis of this serious disease, which is no longer an exclusively pediatric disease. This paper aims to review the changes in the incidence and survival of CF and to assess the impact of the discovery of the responsible gene (the CFTR gene) on these changes. The incidence of CF appears to be decreasing in most countries andpatient survival, which can be monitored by various indicators, has improved substantially, with an estimated median age of survivalof approximately50 years today. Cloning of the CFTR gene 30 years ago and efforts to identify its many mutations have greatly improved the management of CF. Implementation of genetic screening policies hasenabled earlier diagnosis (via newborn screening), in addition to prevention within families or in the general population in some areas (via prenatal diagnosis, family testing or population carrier screening). In the past decade, in-depth knowledge of the molecular bases of CF has also enabled the emergenceof CFTR modulator therapies which have led to major clinical advances in the treatment of CF. All of these phenomena have contributed to changing the face of CF. The advent of targeted therapies has paved the way for precision medicine and is expected to further improve survival in the coming years.

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

Purpose

Newborn screening (NBS) for cystic fibrosis (CF) can identify carriers, which is considered a benefit that enables reproductive planning. We examined the reproductive impact of carrier result disclosure from NBS for CF.

Methods

We surveyed mothers of carrier infants after NBS (Time-1) and one-year later (Time-2) to ascertain intended and reported communication of their infants’ carrier results to relatives, carrier testing for themselves/other children and reproductive decisions. A sub-sample of mothers was also interviewed at Time-1 and Time-2.

Results

Response rate was 54%. Just over half (55%) of mothers carrier tested at Time-1; a further 40% of those who intended to test at Time-1 tested at Time-2. Carrier result communication to relatives was high (92%), but a majority of participants did not expect the results to influence family planning (65%). All interviewed mothers valued learning their infants’ carrier results. Some had carrier testing and shared results with family. Others did not use the results or used them in unintended ways.

Conclusion

While mothers valued learning carrier results from NBS, they reported moderate uptake of carrier testing and limited influence on family planning. Our study highlights the secondary nature of the benefit from disclosing carrier results from NBS.

Highlighting the impact of cascade carrier testing in cystic fibrosis families

BACKGROUND

Cascade carrier testing within cystic fibrosis (CF) affected families offers relatives of CF patients the opportunity to know their status regarding the mutation that segregates within their family, and thus to make informed reproductive choices. As an Australian study has recently shown that this test seemed underused, we searched to assess uptake of this test in a European area where CF is common, and to report its public health implications.

METHODS

This study relied on 40 CF-affected families from western Brittany, France. Investigations included drawing of family trees and registration of carrier tests performed in those families.

RESULTS

Of the 459 relatives eligible for testing, 185 were tested, leading to an adjusted uptake rate of testing of 40.7% (95% CI: [34.1%; 47.3%]). The main predictors for having testing were being female (p=0.031) and having a high prior risk (p<0.001). Planning a pregnancy or expecting a child (reported in at least 38.4% of tested relatives) also appeared critical in choosing to be tested. Overall, carrier testing allowed to reassure more than 1/4 of the relatives and to detect five new 1-in-4 at-risk couples who then requested prenatal diagnosis.

CONCLUSIONS

This observational study assesses, for first time in Europe, uptake of CF cascade carrier testing within CF families, which is a critical tool to reassure non-carriers and to detect early new at-risk couples.

Carrier screening by next-generation sequencing: health benefits and cost effectiveness

BACKGROUND

Compared with conventional genotyping, which typically tests for a limited number of mutations, next-generation DNA sequencing (NGS) provides increased accuracy for carrier screening. The objective of this study was to evaluate the cost effectiveness of carrier screening using NGS versus genotyping for 14 of the recessive disorders for which medical society guidelines recommend screening.

METHODS

Data from published literature, population surveys, and expert opinion were used to develop a decision tree model capturing decisions and outcomes related to carrier screening and reproductive health.

RESULTS

Modeling a population of 1,000,000 couples that was representative of the United States population and that contained 83,421 carriers of pathogenic mutations, carrier screening using NGS averted 21 additional affected births as compared with genotyping, and reduced costs by approximately $13 million. As compared with no screening, NGS carrier screening averted 223 additional affected births. The results are sensitive to assumptions regarding mutation detection rates and carrier frequencies in multiethnic populations.

CONCLUSION

This study demonstrated that NGS-based carrier screening offers the greater benefit in clinical outcomes and lower total healthcare cost as compared with genotyping.

PAP assays in newborn screening for cystic fibrosis: a population-based cost-effectiveness study

Objectives

To compare the cost effectiveness of adding a pancreatitis-associated protein (PAP) assay to common immunoreactive trypsinogen (IRT) and DNA cystic fibrosis (CF) newborn screening strategies.

Methods

Using data collected on 553,167 newborns, PAP cut-offs were calculated based on non-inferiority of the detection rates of classical forms of CF. Cost effectiveness was considered from the third-party payer's perspective using only direct medical costs, and the unit costs of PAP assays were assessed based on a micro-costing study. Robustness of the cost-effectiveness estimates was assessed, taking the secondary outcomes of screening (ie. detecting mild forms and CF carriers) into account.

Results

IRT/DNA, IRT/PAP, and IRT/PAP/DNA strategies had similar detection rates for classical forms of CF, but the strategies involving PAP assays detected smaller numbers of mild forms of CF. The IRT/PAP strategy was cost-effective in comparison with either IRT/DNA or IRT/PAP/DNA. IRT/PAP/DNA screening was cost-effective in comparison with IRT/DNA if relatively low value was assumed to be attached to the identification of CF carriers.

Conclusions

IRT/PAP strategies could be strictly cost-effective, but dropping DNA would mean the test could not detect CF carriers. IRT/PAP/DNA strategies could be a viable option as they are significantly less costly than IRT/DNA, but still allow CF carrier detection.

Variants in Solute Carrier SLC26A9 Modify Prenatal Exocrine Pancreatic Damage in Cystic Fibrosis

OBJECTIVES

To test the hypothesis that multiple constituents of the apical plasma membrane residing alongside the causal cystic fibrosis (CF) transmembrane conductance regulator protein, including known CF modifiers SLC26A9, SLC6A14, and SLC9A3, would be associated with prenatal exocrine pancreatic damage as measured by newborn screened (NBS) immunoreactive trypsinogen (IRT) levels.

STUDY DESIGN

NBS IRT measures and genome-wide genotype data were available on 111 subjects from Colorado, 37 subjects from Wisconsin, and 80 subjects from France. Multiple linear regression was used to determine whether any of 8 single nucleotide polymorphisms (SNPs) in SLC26A9, SLC6A14, and SLC9A3 were associated with IRT and whether other constituents of the apical plasma membrane contributed to IRT.

RESULTS

In the Colorado sample, 3 SLC26A9 SNPs were associated with NBS IRT (min P=1.16×10(-3); rs7512462), but no SLC6A14 or SLC9A3 SNPs were associated (P>.05). The rs7512462 association replicated in the Wisconsin sample (P=.03) but not in the French sample (P=.76). Furthermore, rs7512462 was the top-ranked apical membrane constituent in the combined Colorado and Wisconsin sample.

CONCLUSIONS

NBS IRT is a biomarker of prenatal exocrine pancreatic disease in patients with CF, and a SNP in SLC26A9 accounts for significant IRT variability. This work suggests SLC26A9 as a potential therapeutic target to ameliorate exocrine pancreatic disease.

Non-invasive prenatal diagnosis for cystic fibrosis: detection of paternal mutations, exploration of patient preferences and cost analysis

Objectives

We aim to develop non-invasive prenatal diagnosis (NIPD) for cystic fibrosis (CF) and determine costs and implications for implementation.

Methods

A next-generation sequencing assay was developed to detect ten common CF mutations for exclusion of the paternal mutation in maternal plasma. Using uptake data from a study exploring views on NIPD for CF, total test-related costs were estimated for the current care pathway and compared with those incorporating NIPD.

Results

The assay reliably predicted mutation status in all control and maternal plasma samples. Of carrier or affected adults with CF (n = 142) surveyed, only 43.5% reported willingness to have invasive testing for CF with 94.4% saying they would have NIPD. Using these potential uptake data, the incremental costs of NIPD over invasive testing per 100 pregnancies at risk of CF are £9025 for paternal mutation exclusion, and £26 510 for direct diagnosis.

Conclusions

We have developed NIPD for risk stratification in around a third of CF families. There are economic implications due to potential increased test demand to inform postnatal management rather than to inform decisions around termination of an affected pregnancy. © 2015 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.

Preferences for Prenatal Tests for Cystic Fibrosis: A Discrete Choice Experiment to Compare the Views of Adult Patients, Carriers of Cystic Fibrosis and Health Professionals

As new technologies enable the development of non-invasive prenatal diagnosis (NIPD) for cystic fibrosis (CF), research examining stakeholder views is essential for the preparation of implementation strategies. Here, we compare the views of potential service users with those of health professionals who provide counselling for prenatal tests. A questionnaire incorporating a discrete choice experiment examined preferences for key attributes of NIPD and explored views on NIPD for CF. Adult patients (n = 92) and carriers of CF (n = 50) were recruited from one children’s and one adult NHS specialist CF centre. Health professionals (n = 70) were recruited via an e-mail invitation to relevant professional bodies. The key attribute affecting service user testing preferences was no miscarriage risk, while for health professionals, accuracy and early testing were important. The uptake of NIPD by service users was predicted to be high and includes couples that would currently decline invasive testing. Many service users (47%) and health professionals (55.2%) thought the availability of NIPD for CF would increase the pressure to undergo prenatal testing. Most service users (68.5%) thought NIPD for CF should be offered to all pregnant women, whereas more health professionals (68.2%) thought NIPD should be reserved for known carrier couples. The implications for clinical practice are discussed.

Assessing the Disease-Liability of Mutations in CFTR

Over 1900 mutations have been reported in the cystic fibrosis transmembrane conductance regulator (CFTR), the gene defective in patients with cystic fibrosis. These mutations have been discovered primarily in individuals who have features consistent with the diagnosis of CF. In some cases, it has been recognized that the mutations are not causative of cystic fibrosis but are responsible for disorders with features similar to CF, and these conditions have been termed CFTR-related disorders or CFTR-RD. There are also mutations in CFTR that do not contribute to any known disease state. Distinguishing CFTR mutations according to their penetrance for an abnormal phenotype is important for clinical management, structure/function analysis of CFTR, and understanding the molecular and cellular mechanisms underlying CF.

Evidence for decline in the incidence of cystic fibrosis: a 35-year observational study in Brittany, France

BACKGROUND

Cystic fibrosis (CF) is an autosomal recessive disorder whose incidence has long been estimated as 1/2500 live births in Caucasians. Expanding implementation of newborn screening (NBS) programs now allows a better monitoring of the disease incidence, what is essential to make reliable predictions for disease management. This study assessed time trends in the birth incidence of CF over a long period (35 years: 1975-2009) in an area where CF is frequent (Brittany, France) and where NBS has been implemented for more than 20 years.

METHODS

This study enrolled CF patients born in Brittany between January 1st 1975 and December 31st 2009 (n = 483). Time trends in incidence were examined using Poisson regression and mainly expressed using the average percent change (APC).

RESULTS

The average number of patients born each year declined from 18.6 in the late 1970's (period 1975-79) to 11.6 nowadays (period 2005-09). The corresponding incidence rates dropped from 1/1983 to 1/3268, which represented a decline close to 40% between these two periods (APC = -39.3%, 95% CI = -55.8% to -16.7%, p = 0.0020). A clear breakpoint in incidence rate was observed at the end of the 1980's (p < 0.0001). However, the incidence rate has remained quite stable since that time (annual APC = -1.0%, 95% CI = -3.0% to 1.1%, p = 0.3516).

CONCLUSIONS

This study provides an accurate picture of the evolution of the incidence of a genetic disease over a long period and highlights how it is influenced by the health policies implemented. We observed a 40% drop in incidence in our area which seems consecutive to the availability of prenatal diagnosis.

Nonvisualization of fetal gallbladder increases the risk of cystic fibrosis

OBJECTIVE

The aim of our study is to evaluate the prevalence of cystic fibrosis (CF) in fetuses referred for genetic testing because of ultrasonographic sign (nonvisualized fetal gallbladder--NVFGB).

METHOD

We reviewed the results of CFTR gene analysis over the period 2002 to 2009 in all consecutive cases referred because of NVFGB in Western France. We correlated these data with the presence of a more classical ultrasonographic finding (fetal echogenic bowel - FEB).

RESULTS

Cystic fibrosis was diagnosed in 5 of the 37 fetuses with NVFGB (13.5%, 95% confidence interval (CI): [2.5%; 24.5%]) and in only 9 of the 229 other cases referred because of FEB (3.9%, 95% CI: [3.2%; 14.7%]). In our series, all CF-affected fetuses with NVFGB also had FEB. The risk of CF was 11.6-fold higher in fetuses with both indications (NVFGB + FEB) than in fetuses with isolated FEB (45.5% vs 3.9%, RR = 11.6, 95% CI: [4.7%; 28.8%], p = 0.0001). We also estimated that the residual risk of CF was less than 1 in 68 (1.5%) when a single mutation was identified in the fetus by our molecular protocol.

CONCLUSION

Ultrasonographic evidence of NVFGB is an additional risk factor for CF in cases with FEB.

Focus on cystic fibrosis and other disorders evidenced in fetuses with sonographic finding of echogenic bowel: 16-year report from Brittany, France

OBJECTIVE

Pregnancies medical follow-up and ultrasonography development have enabled detection of fetal echogenic bowel, a sign associated with various pathologies, including cystic fibrosis. Based on the long experience of a region where cystic fibrosis is frequent (Brittany, France), we describe disorders diagnosed in fetal echogenic bowel fetuses and assess ultrasonography ability in detecting cystic fibrosis in utero.

STUDY DESIGN

We reviewed the cases of fetal echogenic bowel diagnosed in pregnant women living in Brittany and referred for CFTR gene analysis over the 1992-2007 period (n = 289).

RESULTS

A disorder was diagnosed in 32.2% of the fetuses, cystic fibrosis being the most commonly identified (7.6%). We also found digestive malformations (7.0%), chromosomal abnormalities (3.7%), and maternofetal infections (3.7%). Combining these data with our ongoing newborn screening program since 1989 showed that ultrasonography enabled diagnosis of 10.7% of the cystic fibrosis cases.

CONCLUSION

This study highlights the importance of pregnancy ultrasound examinations and their efficiency in detecting cystic fibrosis.

Pulmonary outcome differences in U.S. and French cystic fibrosis cohorts diagnosed through newborn screening

BACKGROUND

A comparison of the longitudinal progression of lung disease in cystic fibrosis patients identified through newborn screening (NBS) in cohorts located in two different countries has never been performed and was the primary objective of this study.

METHODS

The study included 56 patients in Brittany diagnosed through NBS between 1989 and 1994 and 69 similar patients in Wisconsin between 1985 and 1994. The onset and progression of lung disease was radiographically quantified using the Wisconsin Chest X-ray (WCXR) scoring system. A single pediatric pulmonologist blinded to all identifiers scored the films.

RESULTS

Generalized estimating equation analyses adjusted for age, genotype, sex, pancreatic insufficiency, and meconium ileus showed worse WCXR scores in Brittany patients compared to Wisconsin patients (average score difference=4.48; p<0.001). Percent predicted FEV1 was also worse among Brittany patients (p<0.001).

CONCLUSIONS

The finding of milder radiographically-quantified lung disease using the WCXR scoring system, as well as better FEV1 values, may be explained by variations in nutrition, environmental exposures, or healthcare delivery.

Newborn screening for cystic fibrosis offers an advantage over symptomatic diagnosis for the long term benefit of patients: the motion for

Comprehensive newborn screening for cystic fibrosis has occurred for more than 25 years in some regions and the results of randomised controlled trials reporting the outcomes have been published. Testing protocols for CF have recently been reviewed and the sensitivity and specificity of these protocols are high. In spite of this, many remain sceptical in respect of the advantages conferred by newborn screening for CF. Every study of newborn screening has shown that diagnosis occurs at a significantly younger age. While this alone is sufficient to justify newborn screening, the clinical course of those diagnosed via newborn screening indicates that many additional advantages accrue. These include a decreased morbidity and mortality in early life, facilitation of better growth and prevention of vitamin deficiency in early infancy, as well as some indication of an advantage in terms of pulmonary status later in life. This review summarises the arguments in favour of newborn screening for CF.

Incidence of cystic fibrosis in the Albanian population

BACKGROUND

Cystic fibrosis (CF) is the most common life-threatening genetic disease in the Western world. Its incidence varies between 1:4,000 and 1:2,500 among Europeans. No data are available on the incidence of CF among Albanians, mainly due to difficulties of the local health system.

GOALS

To estimate the incidence of CF and the prevalence of healthy carrier status among Albanian ethnic people; to evaluate the incidence of hypertrypsinaemia at birth among Albanian newborns.

METHODS

We used the database of the newborn screening of Tuscany, Italy for the period 1991-2005. Children born to both Albanian parents in Tuscany were identified and incidences were calculated.

RESULTS

The incidence of CF among Albanians (1/555, 99% CI: 1/2,980-1/306) was significantly higher than the rest of the Tuscan population (1/4,101, 99% CI: 1/5,564-1/3,248). The prevalence of CF carrier status among Albanians living in Tuscany is estimated to be 1/12 (99%CI 1/27-1/9) while in the rest of the Tuscan population it is 1/32 (99%CI 1/37-1/28). The incidence of hypertrypsinaemia at birth among Albanian newborns (1/55 99%CI: 1/74-1/44) was significantly higher than in the rest of the population (1/84, 99%CI 1/88-1/82).

CONCLUSION

The incidence of CF among Albanians is considerably higher than expected. Albanian people have a risk to give birth to children with CF higher than the rest of Europeans. The implementation of a newborn screening program in Albania, together with a CF follow up program is highly advisable.

Implementation of the French nationwide cystic fibrosis newborn screening program

OBJECTIVES

To describe optimization of a nationwide newborn screening program for cystic fibrosis (CF) that combines an immunoreactive trypsinogen (IRT) assay and DNA mutation analysis in dried blood samples at day 3.

STUDY DESIGN

Data from regional screening laboratories and CF care centers were centralized and periodically analyzed to allow adaptation, thus limiting the number of false-positive cases.

RESULTS

A total of 2717905 infants were screened between 2002 and 2005. Flow chart protocol was modified twice. First, the IRT d3 cutoff value increased from 60 to 65 microg/L, thus decreasing the percentage of samples requiring mutation analysis from 0.82% to 0.64%. Second, for infants with no mutations using the screening panel, a recall for IRT was performed only if IRT d3 was > 100 microg/L; the percentage of recalls decreased from 0.51% to 0.12%, and the percentage of infants requiring a sweat test decreased from 0.14% to 0.01%. No significant change in the CF detection rate was observed after these 2 modifications. A total of 625 CF cases were detected, and 22 false-negative findings (3.4%) were observed, most of them inevitable, with a low initial IRT.

CONCLUSIONS

The centralized data analysis led to changes in the screening strategy to optimise the newborn screening program.

Prenatal diagnosis of cystic fibrosis: the 18-year experience of Brittany (western France)

OBJECTIVE

This study reports 18 years of experience in prenatal diagnosis (PD) of cystic fibrosis (CF) in a region where CF is frequent and the uptake of PD is common (Brittany, western France).

METHOD

All PDs made over the period 1989-2006 in women living in Brittany were collected.

RESULTS

We recorded 268 PDs made in 1 in 4 risk couples, plus 22 PDs directly made following the sonographic finding of echogenic bowel. Most of the 268 PDs were done in couples already having CF child(ren) (n = 195, 72.8%). Close to one-fifth followed cascade screening (n = 49, 18.3%), which identified 26 new 1 in 4 risk couples among the relatives of CF patients or of carriers identified through newborn screening (NBS). The remaining PDs were mainly made in couples whose 1 in 4 risk was evidenced following the diagnosis of echogenic bowel in a previous pregnancy (n = 22, 8.2%). Although patients' life expectancy has considerably improved, in our population the great majority of couples chose pregnancy termination when PD indicated that the foetus had CF (95.9%).

CONCLUSION

This study describes the distribution of PDs according to the context in which the 1 in 4 risk was discovered and highlights the real decisions of couples as regards pregnancy termination after a positive PD.

Estimating the age of CFTR mutations predominantly found in Brittany (Western France)

BACKGROUND

Disparities in the spectrum of mutations within the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene are commonly observed in populations from different ethnical and/or geographical origins. The occurrence of CF in Brittany (western France) is one of the highest in populations from Caucasian origin (<1/2000 in specific areas). The W846X(2), 1078delT and G551D mutations, as well as the I1027T polymorphism in cis with the DeltaF508 mutation (currently referred to as p.F508del) are particularly frequent in this area. We investigated the age of the respective variants in the region of interest.

METHODS

Several polymorphic markers surrounding the CFTR gene were genotyped. Allele frequencies as well as mutation rates and other parameters were used to calculate the respective age of the most recent common ancestors in the region of interest by a previously employed, simple likelihood-based method.

RESULTS

Following haplotype reconstruction and simulation, the ages were estimated to be approximately 600, 1000, 1200 and 600 years, respectively (with a 95% confidence interval).

CONCLUSIONS

These datings thus provide historical insights in the context of understanding population migrations. They also underline the usefulness of this method for estimating the age of rare mutations with a limited number of carriers.

Pseudo-Bartter syndrome in a case of cystic fibrosis caused by C1529G and G3978A compound heterozygosity

A beteg nyolc hónapos életkorban került vizsgálatra pár napja észlelt étvágytalanság és mérsékelt elesettség miatt. Laboratóriumi eredményei súlyos hypokalaemiát, hyponatraemiát és hypochloraemiás alkalosist mutattak. Mivel az alacsony szérumelektrolit-értékeknek megfelelően alacsony vizeletelektrolit-ürítés és emelkedett renin-, aldoszteronszint volt észlelhető, az állapot pszeudo-Bartter-szindrómának felelt meg. Felvetődött a mucoviscidosis diagnózisa, ezt az emelkedett verejtékkloridszint igazolta. A cisztás fibrosis transzmembrán regulátor gén 27 exonjának szekvenálása során a szerzők két, ritkán előforduló mutációt detektáltak kevert heterozigóta formában, az egyik a 10. exonban talált C1529G-, a másik a 20. exonban azonosított G3978A-mutáció. Ezek a cserék a mutáció helyén stopkodon létrejöttéhez vezetnek mindkét allélon (S466X és W1282X). A mutációk közül az első hordozását az egyébként tünetmentes anyában, az utóbbiét a szintén panaszmentes apában sikerült kimutatni. A gyermekben és az anyában a fentiek mellett a 17-es exonban még egy G3341A-mutációt is találtak, ami elméletileg R1070Q-aminosav-cserével is jár. A gyakorlatban azonban ez nem következhet be a gyermekben a C1529G-mutációval társuló stopkodon kialakulása miatt, így következménnyel sem kell számolni. Ezek az eltérések ΔF508-mutációval kombinálva eltérő súlyosságú tüneteket okoznak a különböző betegekben; együttes előfordulásukról azonban a szerzőknek nincs ismeretük. A beteg másfél éves nyomon követése során a kórlefolyás benignusnak tűnt.

Time trends in birth incidence of cystic fibrosis in two European areas: data from newborn screening programs

OBJECTIVE

To determine the incidence of cystic fibrosis (CF) and its time trends over a 16-year period (1990 to 2005) in 2 European regions with a long history of newborn screening (NBS) for CF, and to investigate the impact of some external factors.

STUDY DESIGN

This study focused on data from NBS and prenatal diagnosis (PD) in Brittany (western France) and Veneto/Trentino Alto-Adige (northeastern Italy).

RESULTS

Similar birth incidences of CF were observed in the 2 regions (1/3153 vs 1/3540; P = .245). Time trend analysis using Poisson regression revealed that the birth incidence decreased significantly in the Italian area only (average annual percent change [AAPC] = -4.7%; 95% confidence interval [CI] = -7.3 to -2; P = .0008). The use of PD appeared more common in Brittany, and considering the terminations of CF-affected fetuses, the adjusted incidence was 1/2191 in Brittany and 1/3116 in Veneto/Trentino, corresponding to variations of 30.5% (highly significant; P = .0002) and 12% (not significant; P = .16), respectively. Recording the reason for each PD allowed ready assessment of the affect of various public health policies on incidence. The affect of population mixing also appeared to be relevant in the Italian area.

CONCLUSIONS

This study highlights how the incidence of CF has evolved in 2 European regions that have different attitudes toward PD and immigration policy.

A sweat test centered protocol for the disclosure and diagnosis of cystic fibrosis in a newborn screening program

We describe the development of a sweat test centered protocol for disclosure and diagnosis of Cystic Fibrosis. Our protocol aims to identify infants early, minimizes the time of uncertainty for the parents, and yet gives them time to begin to come to terms with the possibility of diagnosis. Over a 9-year period 295,247 newborn infants were screened for CF in Wales, of whom 121 infants were diagnosed as having CF. During this period there were four false negatives (3.3%). Parental satisfaction with the process appears very high 6 months after disclosure.

Newborn screening for cystic fibrosis: techniques and strategies

Newborn screening for cystic fibrosis has been carried out for over 25 years, and clinical and cost benefits have been documented. There is still much variation in the methods and strategies adopted. All current screening programmes use a measurement of immunoreactive trypsin as a primary screening test, and in most, a second tier test involves analysing DNA mutations. The choice of DNA mutations depends on the genetic background in the region, and considerations of cost. Using DNA analysis as part of a screening procedure has introduced unwanted carrier detection, and protocols have now been devised in an attempt to avoid this. There are at least seven distinct protocols in use, all of which have different advantages and disadvantages, and no method or strategy will suit every region. Further careful study of performance and costs of various strategies is needed.

Newborn screening for CF in a regional paediatric centre: The psychosocial effects of false-positive IRT results on parents

Neonatal screening for cystic fibrosis (CF) has been established in Leeds since 1975. The current method is measuring IRT and genotyping. Newborn screening for CF results in a small but significant number of false positives. This study explored the psychosocial reactions to such results in a group of parents (N=21) using semi-structured interviews. Responses were analysed using descriptive statistics and well-validated content analysis. Mothers described a range of emotions during the screening process including anxiety, distress and upset. Waiting for the repeat IRT test results was identified as the most emotionally difficult stage. Discussion focuses on good practice and implications for CF services.

Extended gene analysis can increase specificity of neonatal screening for cystic fibrosis

AIM

To assess whether carriers and patients can be accurately identified by extended gene analysis for cystic fibrosis (CF) in dried blood spots.

METHODS

A blinded analysis was performed in 10-mm2 blood spots on Guthrie cards, punched as if to remove material for the IRT test, from 10 CF patients and 10 carriers with known CF mutations. Genomic DNA was isolated. Aliquots of 1 microl dissolved DNA were used for subsequent PCRs. Analysis of the deltaF508 mutation was followed by an oligonucleotide ligation assay. Denaturing gradient gel electrophoresis of the whole CFTR gene was carried out in samples with only one identified mutation. Amplicons revealing an aberrant pattern were sequenced.

RESULTS

In all cases, the blood-spot genotype was identical to that previously determined from whole-blood analysis. Estimated time needed to complete the procedure in a series of Guthrie cards was 3-4 wk.

CONCLUSION

Extended gene analysis in dried blood spots can discriminate CF patients and carriers. If proven equally reliable in larger series, an approach to neonatal screening in which tests are only considered as screen positive when two CF mutations are found is possible. This can increase the specificity of the screening programme, and carrier detection can practically be avoided.

Immunoreactive trypsin/DNA newborn screening for cystic fibrosis: should the R117H variant be included in CFTR mutation panels?

BACKGROUND

Cystic fibrosis newborn screening is now implemented universally in France, as well as in many states in the United States and in various areas of Europe and Australia. Because the screening protocol usually includes the analysis of the most common CFTR mutations, it is of the utmost importance that only mutations that result in classical cystic fibrosis are included in this test. The panels of mutations used in most cystic fibrosis newborn screening programs enable the detection of a relatively frequent CFTR variant (R117H) whose implication in cystic fibrosis remains unclear. Physicians, therefore, have difficulty managing detected compound heterozygotes with this variant, which raises the issue of the appropriateness of extended testing in families and of the legitimate use of prenatal diagnosis.

OBJECTIVE

The aim of this study was to describe the clinical outcome of the children found to be compound heterozygous for R117H by screening in Brittany (western France), where cystic fibrosis newborn screening was set up in 1989, and to assess whether this CFTR variant should be included in the newborn screening mutation panels.

METHODS

Data on clinical status were obtained by the referring pediatricians.

RESULTS

Since our screening protocol has enabled detection of R117H (ie, in 1995), 360466 newborns have been screened for cystic fibrosis in Brittany, of whom 124 had elevated immunoreactive trypsin and 2 mutations in the CFTR gene. Nine of these children (7.3%) were compound heterozygous for R117H, which in all cases was linked to the 7T_11TG haplotype [IVS8-nT variant/m(TG) repeat]. Their genotypes were F508del/R117H (n = 7), I507del/R117H (n = 1), or G551D/R117H (n = 1). At the time of this writing, the mean age of these 9 children was 7.0 years (the oldest being >10 years of age), and none of them had yet developed any signs of cystic fibrosis; they have been pancreatic sufficient and have had good nutritional status and pulmonary function. Moreover, we observed that, in Brittany, all the patients carrying the R117H variant have been identified exclusively through cystic fibrosis newborn screening.

CONCLUSIONS

In view of the high frequency of R117H-7T identified by cystic fibrosis newborn screening, the uncertain outcome of the asymptomatic children, and physicians' difficulty in managing these situations, we propose the withdrawal of the R117H variant from the panels of CFTR mutations used in cystic fibrosis newborn screening, given the expanding implementation of cystic fibrosis newborn screening.

Changing their minds with time: a comparison of hypothetical and actual reproductive behaviors in parents of children with cystic fibrosis

OBJECTIVE

Newborn screening for cystic fibrosis, with appropriate counseling, enables carrier parents to be informed early about future reproductive choices. Previous studies have assessed attitudes toward reproductive decisions in a hypothetical pregnancy or have measured reproductive behaviors. We aimed to measure parent attitudes to reproductive technologies and to compare prospectively these attitudes with later reproductive behaviors.

METHODS

Parents of children who had cystic fibrosis and were aged 2 to 7 years were surveyed at baseline using a written questionnaire that explored attitudes to prenatal testing and termination of pregnancy in a hypothetical pregnancy. Parent knowledge and access to genetic counseling services also were assessed. Five years later, we compared attitudes with actual reproductive behaviors.

RESULTS

Fifty-six mothers participated at baseline, and 43 were resurveyed 5 years later. Parent knowledge of cystic fibrosis and genetics was very good. A total of 93% had met a genetic counselor at the time of diagnosis, and more than half had on at least 1 subsequent occasion. At baseline, 82% reported that they would be likely to have prenatal diagnosis in a subsequent pregnancy, and 56% reported that they would be likely to terminate an affected pregnancy. Twenty-seven mothers since had been pregnant, with prenatal diagnosis used in 33 of the 55 pregnancies. In 67%, the hypothetically reported behavior regarding use of prenatal testing was the same as their actual behavior. Five of the 33 tested pregnancies were affected; all ended in termination. Reproductive choices in relationship to the number of children wanted, together with attitudes toward prenatal diagnosis and termination of pregnancy, were dynamic over time, with decisions having changed in both directions.

CONCLUSIONS

This cohort of parents has actively used reproductive technologies since the birth of a child who has cystic fibrosis that was diagnosed by newborn screening. The dynamic aspect of reproductive choices highlights the importance of ongoing access to genetic counseling beyond the initial period of diagnosis and education, regardless of whether parents report that they expect to use reproductive technologies.

Cost-effectiveness of 4 neonatal screening strategies for cystic fibrosis

OBJECTIVES

The purpose of this work was to assess the costs of 4 neonatal screening strategies for cystic fibrosis in relation to health effects. In each strategy, the first test was the measurement of serum concentration of immunoreactive trypsin. The second step consisted of either a second immunoreactive trypsin test (strategy 1) or a multiple mutation analysis (strategy 2). In strategies 3 and 4, a third step was added to strategy 2: a second immunoreactive trypsin test (strategy 3) or an extended mutation analysis of the cystic fibrosis gene, that is, a denaturing gradient gel electrophoresis analysis (strategy 4).

METHODS

We conducted an economic-modeling exercise in the Netherlands based on published data and expert opinions. Subjects were a hypothetical cohort of 200 000 neonates, the approximate number of children born annually in the Netherlands, and we assessed the costs and number of life-years gained as a result of neonatal screening for cystic fibrosis. The costs and effects of changes in reproductive decisions because of neonatal screening were also assessed.

RESULTS

Immunoreactive trypsin + immunoreactive trypsin had the most favorable cost-effectiveness ratio of 24,800 euro per life-year gained. Immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis achieved more health effects than immunoreactive trypsin + DNA + immunoreactive trypsin at lower cost. The incremental costs per life-year gained of the immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis strategy compared with the immunoreactive trypsin + immunoreactive trypsin strategy were 130,700 euro, whereas the incremental costs of the immunoreactive trypsin + DNA strategy compared with the immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis strategy were 2,154,300 euro. When changes in reproductive decisions as a result of neonatal screening are also taken into account, neonatal screening for cystic fibrosis may lead to financial savings of approximately 1.8 million euro annually, depending on the screening strategy used.

CONCLUSIONS

Cystic fibrosis screening for neonates is a good economic option, and positive health effects can also be expected. Immunoreactive trypsin + immunoreactive trypsin and immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis are the most cost-effective strategies.

Challenges in implementing a successful newborn cystic fibrosis screening program

OBJECTIVE

To identify necessary components of a successful cystic fibrosis (CF) newborn screening (NBS) program.

STUDY DESIGN

The approach to CF NBS used by the Massachusetts NBS program was examined.

RESULTS

Several key components were identified that should be addressed when a state has made the decision to screen, and well in advance of actual implementation. These components include (1) inclusion of CF center directors in the development process; (2) logistics of choosing a screening algorithm relative to practices in place and community wishes; (3) projections of medical service needs from specific algorithms; (4) identification of critical reporting components; (5) identification of critical follow-up components; and (6) recognition of educational needs.

CONCLUSIONS

Careful examination of a wide variety of issues is needed to ensure optimal implementation of NBS for CF.

Risk calculations for cystic fibrosis in neonatal screening by immunoreactive trypsinogen and CFTR mutation tests

PURPOSE

Although neonatal screening (or newborn screening) for cystic fibrosis (CF) is commonly practiced, systematic methods for accurate risk calculations are currently lacking.

METHODS AND RESULTS

We evaluated characteristics of the immunoreactive trypsinogen (IRT) test using the published data. The probability that a neonate has a positive IRT test, if the neonate is affected, a carrier, or a noncarrier, is approximately 1, 0.041, or 0.011, respectively. We provide methods to calculate genetic risks for a variety of commonly encountered scenarios in which neonates are positive by the IRT test.

CONCLUSION

Our Bayesian methods permit CF disease probabilities to be calculated accurately, taking into account all relevant information.

False-positive results in neonatal screening for cystic fibrosis based on a three-stage protocol (IRT/DNA/IRT): Should we adjust IRT cut-off to ethnic origin?

Since 1979, newborn screening for cystic fibrosis (CF) has been possible by measuring immunoreactive tryspinogen (IRT) in blood spots. In France, a programme based on a three-stage strategy (IRT/DNA/IRT) started in 2002. In the Rhône-Alpes area, the positive screening rate (i.e. the proportion of samples sent for genotyping) observed after the first IRT measurement was higher than the expected rate (0.65% versus 0.50%), without a greater CF incidence. We hypothesized that the IRT reference range could differ according to the ethnic origin of the newborns. 35 141 newborns were studied and divided into two groups: European ethnic group 26 324 (75%) and North African ethnic group 8817 (25%). 243 positive newborns were identified: 146 (60%) in the European ethnic group and 97 (40%) in the North African ethnic group. Three CF patients and 11 unaffected heterozygotes were found in the European group, but no mutations were found in the North African group. Mean IRT values and the percentage of IRT values over the cut-off were significantly higher in the North African group than in the European group (mean IRT = 21.17 microg/L and 19.74 microg/L, p < 0.0001; %IRT > cut-off = 1.1% and 0.5%, respectively). For the positive screened newborns, term and IRT mean were comparable, whereas birth weight was higher in the North African ethnic group. These results lead us to conclude that (i) newborns from families of North African origin have higher IRT values and (ii) most of the positive screened newborns in this population could be considered as 'false positives'. These conclusions could explain, in part, the large variations seen in the positive screening rate in the French CF neonatal screening and raise the question whether it is relevant to adapt cut-off to ethnic origin of the newborns.

High heterogeneity of CFTR mutations and unexpected low incidence of cystic fibrosis in the Mediterranean France

In this report, we present updated spectrum and frequency of mutations of the CFTR gene that are responsible for cystic fibrosis (CF) in Languedoc-Roussillon (L-R), the southwestern part of France. A total of 75 different mutations were identified by DGGE in 215 families, accounting for 97.6% of CF genes and generating 88 different mutational genotypes. The frequency of p.F508del was 60.23% in L-R versus 67.18% in the whole country and only five other mutations (p.G542X, p.N1303K, p.R334W, c.1717-1G>A, c.711+1G>T) had a frequency higher than 1%. The mutations were scattered over 20 exons or their border. This sample representing only 5.7% of French CF patients contributed to 24% of CFTR mutations reported in France. This is one of the highest molecular allelic heterogeneity reported so far in CF. We also present the result of a neonatal screening program based on a two-tiered approach "IRT/20 mutations/IRT" analysis on blood spots, implemented in France with the aim to improve survival and quality of life of patients diagnosed before clinical onset. This 18-month pilot project showed an unexpected low incidence of CF (1/8885) in South of France, with only six CF children detected among 43,489 neonates born in L-R, and 13 among 125,339 neonates born in Provence-Alpes-Côte-d'Azur (PACA).

What follows newborn screening? An evaluation of a residential education program for parents of infants with newly diagnosed cystic fibrosis

OBJECTIVE

The diagnosis of a severe life-limiting condition, such as cystic fibrosis (CF), is generally followed by assessment and treatment of the child and education and counseling for parents. The introduction of newborn screening for CF provides an opportunity for standardized assessment and education. The aim of this study was to evaluate a 5-day residential assessment and education program for parents of infants who receive a diagnosis of CF after newborn screening.

METHODS

Eligible parents had a 6- to 30-month-old infant with CF diagnosed by newborn screening. Parents were interviewed by telephone using a structured questionnaire that addressed 3 main themes: 1) initial communication of the diagnosis of CF, 2) the perceived value of the 5-day assessment and education program, and 3) the perceived advantages and disadvantages of the residential component (Care-By-Parent unit) of the program.

RESULTS

Fifteen of 17 eligible families took part in the 5-day assessment and education program, 12 of whom used the residential Care-By-Parent unit. At the end of the program, parents believed that they had the knowledge and skills required to manage their child's CF at home. One hundred percent endorsed the timing of the assessment and education program immediately after the child's diagnosis and would recommend it to other families in the same situation. Perceived advantages of the residential program were not having to travel (89%), being able to concentrate on CF (50%), and the benefit of a "home base" at the hospital (39%). Twenty-two percent reported that financial costs related to participation (paternal time off work) were a disadvantage, 17% reported additional strain on family members caring for siblings, and 17% mentioned lack of comfort within the unit.

CONCLUSIONS

This time-intensive residential program was evaluated positively by parents of children with newly diagnosed CF. It provides a model for education programs after the diagnosis of CF by newborn screening, as well as for other pediatric conditions that require intensive parent education.

Population-based newborn screening for genetic disorders when multiple mutation DNA testing is incorporated: a cystic fibrosis newborn screening model demonstrating increased sensitivity but more carrier detections

OBJECTIVES

Newborn screening for cystic fibrosis (CF) provides a model to investigate the implications of applying multiple-mutation DNA testing in screening for any disorder in a pediatric population-based setting, where detection of affected infants is desired and identification of unaffected carriers is not. Widely applied 2-tiered CF newborn screening strategies first test for elevated immunoreactive trypsinogen (IRT) with subsequent analysis for a single CFTR mutation (DeltaF508), systematically missing CF-affected infants with any of the >1000 less common or population-specific mutations. Comparison of CF newborn screening algorithms that incorporate single- and multiple-mutation testing may offer insights into strategies that maximize the public health value of screening for CF and other genetic disorders. The objective of this study was to evaluate technical feasibility and practical implications of 2-tiered CF newborn screening that uses testing for multiple mutations (multiple-CFTR-mutation testing).

METHODS

We implemented statewide CF newborn screening using a 2-tiered algorithm: all specimens were assayed for IRT; those with elevated IRT then had multiple-CFTR-mutation testing. Infants who screened positive by detection of 1 or 2 mutations or extremely elevated IRT (>99.8%; failsafe protocol) were then referred for definitive diagnosis by sweat testing. We compared the number of sweat-test referrals using single- with multiple-CFTR-mutation testing. Initial physician assessments and diagnostic outcomes of these screened-positive infants and any affected infants missed by the screen were analyzed. We evaluated compliance with our screening and follow-up protocols. All Massachusetts delivery units, the Newborn Screening Program, pediatric health care providers who evaluate and refer screened-positive infants, and the 5 Massachusetts CF Centers and their affiliated genetic services participated. A 4-year cohort of 323 506 infants who were born in Massachusetts between February 1, 1999, and February 1, 2003, and screened for CF at approximately 2 days of age was studied.

RESULTS

A total of 110 of 112 CF-affected infants screened (negative predictive value: 99.99%) were detected with IRT/multiple-CFTR-mutation screening; 2 false-negative screens did not show elevated IRT. A total of 107 (97%) of the 110 had 1 or 2 mutations detected by the multiple- CFTR-mutation screen, and 3 had positive screens on the basis of the failsafe protocol. In contrast, had we used single-mutation testing, only 96 (87%) of the 110 would have had 1 or 2 mutations detectable by single-mutation screen, 8 would have had positive screens on the basis of the failsafe protocol, and an additional 6 infants would have had false-negative screens. Among 110 CF-affected screened-positive infants, a likely "genetic diagnosis" was made by the multiple-CFTR-mutation screen in 82 (75%) versus 55 (50%) with DeltaF508 alone. Increased sensitivity from multiple-CFTR-mutation testing yielded 274 (26%) more referrals for sweat testing and carrier identifications than testing with DeltaF508 alone.

CONCLUSIONS

Use of multiple-CFTR-mutation testing improved sensitivity and postscreening prediction of CF at the cost of increased referrals and carrier identification.

Early intervention and prevention of lung disease in cystic fibrosis: a European consensus

In patients with cystic fibrosis (CF), early intervention and prevention of lung disease is of paramount importance. Principles to achieve this aim include early diagnosis of CF, regular monitoring of the clinical status, various hygienic measures to prevent infection and cross-infection, early use of antibiotic courses in patients with recurrent or continuous bacterial colonisation and appropriate use of chest physiotherapy.

Reproductive attitudes of couples having a child with cystic fibrosis in Brittany (France)

Cystic fibrosis (CF) has an incidence of one in 2,636 livebirths and a carrier rate of one in 26 inhabitants in Brittany. One objective of a major enquiry among parents having a CF child as well as CF adolescents and adults was to evaluate the reproductive behavior of 124 couples attending a CF care center. Knowledge of recurrence risk resulted in deciding against further progeny or in reducing the number of children (average number of children: 1.96; ideal mean number of children: 3.7). Thirty-five percent adopted or changed their method of contraception after the birth of their affected child, but the change was due to the birth of the CF child in only 14.3% of the couples. Prenatal diagnosis (PD) was favored by 95.1%, and 41.2% had used it; 68.6% were in favor of pregnancy interruption for CF and 76.2% would interrupt the pregnancy should PD reveal that their fetus had CF. All 123 respondents thought that genetic counseling was useful, but only 87.1% knew of its availability. Our results are quite different from those previously published. Although results could be population-specific, one cannot exclude the fact that they reflect a change of attitudes among parents, the other studies being much older.

Musculoskeletal manifestations in cystic fibrosis

Although bone and joint manifestations are common in children with cystic fibrosis (CF), they have received little attention in adults. As compared to healthy individuals, bone mineral density is low, even with calcium intakes greater than 1500 mg/d. Nevertheless, calcium and phosphate levels in blood and urine are often normal, and vitamin D levels vary. Short stature with a low body mass index and central hypogonadism are the rule in these patients. Fractures and kyphosis are often reported. CF arthropathy occurs in 2-8.5% of patients. Arthritis develops, and there may be skin eruptions. Non-steroidal antiinflammatory drug therapy is effective. Hypertrophic osteoarthropathy associated with respiratory failure is present in 2-7% of patients. Rheumatoid arthritis, spondyloarthropathies, sarcoidosis, and amyloidosis have been reported in association with CF. Knee pain due to patellofemoral syndrome, quinolone-induced arthropathy, and mechanical back pain have been described. Rheumatoid factor titers are higher than in healthy controls, particularly in patients with episodic arthritis. No data are available on antiperinuclear factor or antikeratin antibody titers. Tests for antinuclear antibody are usually negative. Circulating immune complex levels and antibodies to heat shock proteins may be elevated. Antineutrophil cytoplasmic antibody of the bactericidal/permeability-increasing protein (BPI) or azurocidin (AZ) type has been reported, often in high titers (up to 40%).