Cystic fibrosis carrier screening effects on birth prevalence and newborn screening (original) (raw)
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A 10-year large-scale cystic fibrosis carrier screening in the Italian population
Journal of Cystic Fibrosis, 2010
Background: Cystic Fibrosis (CF) is one of the most common autosomal recessive genetic disorders, with the majority of patients born to couples unaware of their carrier status. Carrier screenings might help reducing the incidence of CF. Methods: We used a semi-automated reverse-dot blot assay identifying the 47 most common CFTR gene mutations followed by DGGE/dHPLC analysis. Results: Results of a 10-year (1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006) CF carrier screening on 57,999 individuals with no prior family history of CF are reported. Of these, 25,104 were couples and 7791 singles, with 77.9% from the Italian Veneto region. CFTR mutations were found in 1879 carriers (frequency 1/31), with ΔF508 being the most common (42.6%). Subjects undergoing medically assisted reproduction (MAR) had significantly (p b 0.0001) higher CF carrier frequency (1/22 vs 1/32) compared to non-MAR subjects. Conclusions: If coupled to counselling programmes, CF carrier screening tests might help reducing the CF incidence.
A survey of newborn screening for cystic fibrosis in Europe
Journal of Cystic Fibrosis, 2007
Background: Cystic fibrosis (CF) is a recessively inherited condition caused by mutation of the CFTR gene. Newborn infants with CF have raised levels of immuno-reactive trypsinogen (IRT) in their serum. Measurement of IRT in the first week of life has enabled CF to be incorporated into existing newborn screening (NBS) blood spot protocols. However, IRT is not a specific test for CF and NBS therefore requires a further tier of tests to avoid unnecessary referral for diagnostic testing. Following identification of the CFTR gene, DNA analysis for common CF-associated mutations has been increasingly used as a second tier test. The aim of this study was to survey the current practice of CF NBS programmes in Europe. Method: A questionnaire was sent to 26 regional and national CF NBS programmes in Europe. Results: All programmes responded. The programmes varied in number of infants screened and in the protocols employed, ranging from sweat testing all infants with a raised first IRT to protocols with up to four tiers of testing. Three different assays for IRT were used; in the majority (24) this was a commercially available kit (Delfia™). A number of programmes employed a second IRT measurement in the 4th week of life (as the IRT is more specific at this point). Nineteen programmes used DNA analysis for common CFTR mutations on samples with a raised first IRT. Three programmes used a second IRT measurement on infants with just one recognised mutation to reduce the number of infants referred for sweat testing. Referral to clinical services was prompt and diagnosis was confirmed by sweat testing, even in infants with two recognised mutations in most programmes. Subsequent clinical pathways were less uniform. Multivariate analysis demonstrated a relationship between the age of diagnosis and the timing of the first IRT. More sweat tests were undertaken if the first IRT was earlier and the diagnosis was later. Conclusions: Annually these programmes screen approximately 1,600,000 newborns for CF and over 400 affected infants are recognised. The findings of this survey will guide the development of European evidence based guidelines and may help new regions or nations in the development and implementation of NBS for cystic fibrosis.
American Journal of Epidemiology, 2002
This population-based study was conducted in Veneto and Trentino (northwestern Italy, population 5 million). In this area, neonatal screening for cystic fibrosis started in 1973 and has been virtually universal since the early 1980s. During this study, the estimated incidence of cystic fibrosis in this region was 1/2,650 livebirths per year. The authors analyzed data on 593 patients born in 1938-2000 and living in the region who were followed by a single referral center. Median time from birth to confirmation of diagnosis after screening was 32 days (range, 0-1,531). For patients whose disease was recognized after symptoms occurred, median age at diagnosis was always less than 1 year. Median survival age was 37.7 years. Long-term survival (to age 20-30 years) was not significantly influenced by mode of diagnosis (screened or unscreened), sex, or age at diagnosis for unscreened patients (<1, 1-5, >5 years). Current survival analysis of three consecutive decades showed that improving survival tended to vanish in the last years of the study. The authors concluded that a regional neonatal screening program allows very early recognition of cystic fibrosis. They could not conclude that neonatal screening improves long-term survival if compared with diagnosis by symptoms in early infancy.
Journal of Medical Screening, 2002
Objective: To assess the performance of a two tier neonatal screening programme (IRT/DNA/IRT) for cystic fibrosis, based on immunoreactive trypsinogen (IRT) followed by direct cystic fibrosis transmembrane conductance regulator (CFTR) gene analysis (based on a panel of up to 31 mutations) in hypertrypsinaemic newborn infants and to compare it with a previous screening protocol. Setting: The study comprised all the newborn infants in the period 1 October 1998 to 31 December 1999 in the Lombardia region, north western Italy. Methods: The screening strategy consisted of an immunoreactive trypsinogen assay from dried blood spots, a polymerase chain reaction (PCR) followed by an oligonucleotide ligation assay (PCR-OLA), and a sequence code separation. Results: 104 609 newborn infants were screened. 1457 hypertrypsinaemic infants (1.39%) were analysed with the PCR-OLA assay. 18 newborn homozygotes or compound heterozygotes for CFTR mutations were identified and referred to the cystic fibrosis (CF) centre at a mean age of 3 weeks. 125 infants presenting only one mutation were recalled for a sweat test: a diagnosis of CF was made in 13 infants, and parents of 112 neonates identified as carriers (1:13) received genetic counselling. The remaining 1314 hypertrypsinaemic newborn infants were recalled for IRT retesting and 177 were referred for a sweat test because the second IRT measurement was above the cut off value. Among this group a further two infants were diagnosed with CF (1.1%) leading to a CF prevalence of 1:3170. Conclusions: This strategy resulted in an early and accurate diagnosis of CF. The IRT/DNA/IRT protocol with an OLA assay was shown to be useful in an Italian population with a genetic heterogeneity, leading to the identification of 94% of infants with CF.
Newborn screening for cystic fibrosis in Serbia: a pilot study
Pediatrics international : official journal of the Japan Pediatric Society, 2013
We performed a pilot study of neonatal screening for cystic fibrosis (CF) in order to introduce it to the national screening program in Serbia. Immunoreactive trypsinogen (IRT) concentrations were analyzed in dried blood spot samples. Patients were recalled for repeated measurements in case of high IRT levels. Persisting high IRT levels resulted in DNA testing for the 29 most common mutations in the CF transmembrane regulator (CFTR) gene (IRT/IRT/DNA method). Sweat chloride measurements and clinical assessment were further performed for newly diagnosed patients. Of 1000 samples, three were initially positive and were further analyzed for the presence of the most common CFTR mutations in the Serbian population. DNA analysis revealed two patients being homozygous for F508del mutation. One sample was false positive, as the genetic test proved to be negative and associated with normal sweat chloride concentration and unremarkable clinical presentation. The results of our pilot study justified the expanding of the routine neonatal screening program in Serbia with CF. Data could be used in future in order to obtain accurate incidence of CF and carrier prevalence in our country.
Declining prevalence of cystic fibrosis since the introduction of newborn screening
Archives of Disease in Childhood, 2010
Objectives Newborn screening for cystic fi brosis (CF) facilitates early diagnosis and genetic counselling for parents of affected infants. Many parents elect to use prenatal testing for subsequent pregnancies, and this may affect the prevalence of CF. The aim of this study was to assess the evidence for changes in the live-birth prevalence of CF since the introduction of newborn screening for CF. Methods The authors reviewed the records of the Victorian newborn screening programme and the clinical records of the three centres caring for patients with CF in Victoria, Australia, in order to determine the live-birth prevalence of patients with CF; before (1979-1988) and after (1989-2006) the introduction of newborn screening. The authors reviewed the records of the Victorian Clinical Genetics Service to ascertain the number and outcome of prenatal tests for CF (1979-2006). Live births in Victoria were obtained from the state birth register. Findings Between 1979 and 1988, the live-birth prevalence of CF was 3.96 (95% CI 3.48 to 4.49) per 10 000 live births. Following the introduction of newborn screening (1989-2006) the live-birth prevalence of CF was 3.28 (95% CI 2.97 to 3.63) per 10 000 live births, representing a reduction of 17% (95% CI 2% to 29%, p=0.025). In the prescreening period, there were 10 prenatal tests, which identifi ed three affected pregnancies, all of which were terminated. In the later period, there were 304 prenatal tests (mean 17/year), of which 76 were affected, and 70 of these pregnancies were terminated. Conclusion The authors observed a modest reduction in the live-birth prevalence of CF since the introduction of newborn screening. This is principally due to at-risk couples detected by newborn screening electing to use prenatal testing on subsequent pregnancies.
Antenatal cystic fibrosis carrier screening—whether, when and how?
Paediatric and Perinatal Epidemiology, 1993
Population screening for camers of cystic fibrosis ( 0 is now possible. Such screening may have both advantages and disadvantages and hence must be evaluated before it becomes routine practice. As the potential benefits of screening are wide and the drawbacks may include psychological effects, a combination of approaches is needed to assess screening thoroughly instead of only counting numbers of terminations or carrier tests. We describe the issues concerned and our methodology for a rigorous evaluation of population antenatal carrier screening for cystic fibrosis.
The expansion and performance of national newborn screening programmes for cystic fibrosis in Europe
Journal of cystic fibrosis : official journal of the European Cystic Fibrosis Society, 2017
Newborn screening (NBS) for cystic fibrosis (CF) is a well-established public health strategy with international standards. The aim of this study was to provide an update on NBS for CF in Europe and assess performance against the standards. Questionnaires were sent to key workers in each European country. In 2016, there were 17 national programmes, 4 countries with regional programmes and 25 countries not screening in Europe. All national programmes employed different protocols, with IRT-DNA the most common strategy. Five countries were not using DNA analysis. In addition, the processing and structure of programmes varied considerably. Most programmes were achieving the ECFS standards with respect to timeliness, but were less successful with respect to sensitivity and specificity. There has been a steady increase in national CF NBS programmes across Europe with variable strategies and outcomes that reflect the different approaches.
Neonatal screening for cystic fibrosis in São Paulo State, Brazil: a pilot study
Brazilian journal of medical and biological research = Revista brasileira de pesquisas médicas e biológicas / Sociedade Brasileira de Biofísica ... [et al.], 2009
Cystic fibrosis is one of the most common autosomal recessive hereditary diseases in the Caucasian population, with an incidence of 1:2000 to 1:3500 liveborns. More than 1000 mutations have been described with the most common being F508del. It has a prevalence of 23-55% within the Brazilian population. The lack of population-based studies evaluating the incidence of cystic fibrosis in São Paulo State, Brazil, and an analysis concerning the costs of implantation of a screening program motivated the present study. A total of 60,000 dried blood samples from Guthrie cards obtained from April 2005 to January 2006 for neonatal screening at 4 reference centers in São Paulo State were analyzed. The immunoreactive trypsinogen (IRT)/IRT protocol was used with the cut-off value being 70 ng/mL. A total of 532 children (0.9%) showed IRT >70 ng/mL and a 2nd sample was collected from 418 (80.3%) of these patients. Four affected children were detected at two centers, corresponding to an incidenc...