Cessation of smoke exposure improves pediatric CF outcomes: Longitudinal analysis of CF Foundation Patient Registry data.

BACKGROUND: Tobacco smoke exposure is a major risk factor for the health of children and adolescents with CF. In this study, we assess whether cessation of smoke exposure is associated with improved outcomes in this population. METHODS: We used annualized and encounter-based data from the U.S. CF Foundation Patient Registry (2006-2018) on all individuals born 1998-2010. The analytical sample included those who ever reported second-hand smoke exposure (daily or weekly), ever lived with a smoker, or ever reported smoking themselves. We used non-linear mixed models for pulmonary exacerbations and linear mixed models for ppFEV1 and BMI as a function of ceased exposure. RESULTS: The sample included 3,633 individuals contributing 19,629 person-years. Cessation of smoke exposure reduced the odds of a pulmonary exacerbation in 12 months by 17% (OR 0.83, p < 0.001) in the first year of cessation, with an additional 6% decrease (OR 0.94, p = 0.003) for each additional year of cessation. Cessation was associated with improvements in ppFEV1 and BMI: 0.7% ppFEV1 increase (p < 0.001) in the first year of cessation and 0.4% increase (p = 0.001) for each additional year of cessation; 1% increase in BMI percentile (p < 0.001) in the first year of cessation plus 0.4% increase (p = 0.009) for each additional year. Three years of cessation reduce the predicted probability of a pulmonary exacerbation in 12 months by 8% and improve ppFEV1 and BMI by 2%. CONCLUSION: Eliminating smoke exposure may reduce pulmonary exacerbations and improve respiratory and nutritional outcomes in children and adolescents with CF. Both smoking cessation and exposure prevention should be prioritized in pediatric CF care.

A Transparent Approach to Calculate Detection Rate and Residual Risk for Carrier Screening.

Carrier screening involves detection of carrier status for genes associated with recessive conditions. A negative carrier screening test result bears a nonzero residual risk (RR) for the individual to have an affected child. The RR depends on the prevalence of specific conditions and the detection rate (DR) of the test itself. Herein, we provide a detailed approach for calculating DR and RR. DR was calculated on the basis of the sum of disease allele frequencies (DAFs) of pathogenic variants found in published literature. As a proof of concept, DAF data for cystic fibrosis were compared with society guidelines. The DAF data calculated by this method were consistent with the published cystic fibrosis guideline. In addition, we compared DAF for four genes (ABCC8, ASPA, GAA, and MMUT) across three laboratories, and outlined the likely reasons for discrepancies between these laboratories. The utility of carrier screening is to support couples with information while making reproductive choices. Accurate development of DR and RR is therefore critical. The method described herein provides an unbiased and transparent process to collect, calculate, and report these data.

Extraction of the molecular level biomedical event trigger based on gene ontology using radial belief neural network techniques.

Detection of molecular level biomedical event extraction plays a vital role in creating and visualizing the applications related to natural language processing. Cystic Fibrosis is an inherited genetic and debilitating pathology involving the respiratory and digestive systems. The excessive production of thick sticky mucus on the outside of the cells is the main consequence of such disease. This includes disease prevention and medical search to signify the occurrence and detection of event triggers, which is regarded as a proper step in an event extraction of molecular level in biomedical applications. In this model, use a rich set of extracted features to feed the machine learning classifier that helps in better extraction of events. The study uses an automatic feature selection and a classification model using Radial Belief Neural Network (RBNN) for the optimal detection of molecular biomedical event detection. The Radial Belief Neural Network (RBNN) is the proposed system is implemented and it is the classifier to give accurate result of the disease detection. These three algorithms are used to enhance the generalization performance and scalability of detecting the molecular event triggers. The validation is conducted on the cystic fibrosis event trigger based on the gene ontology bio system using the RBNN model with a lung molecular event-level extraction dataset. The extensive computation shows that the Radial Belief Neural Network (RBNN) is proposed to given the better performance results like Accuracy, Sensitivity, Specificity, F-measure and Execution time.

Cost-effectiveness of the CFTR gene-sequencing test for asymptomatic carriers in the Colombian population / [Costo-efectividad de la prueba de secuenciación del gen CFTR para portadores asintomáticos en la población colombiana].

Introduction: Cystic fibrosis is an autosomal recessive genetic disease classified as a highcost orphan disease. Objective: To determine the cost-effectiveness ratio of the diagnostic test for the CFTR gene-sequencing in asymptomatic family carriers in the first, second, and third degree of consanguinity. Materials and methods: We conducted a systematic search evaluating operative characteristics of the diagnostic test and decision-tree models in cost-effectiveness studies. A decision-tree model was elaborated taking prevention of future conceptions as a unit of analysis. We obtained the costs of the disease from the high-cost report of the Ministerio de Salud y Protección Social. The costs of the test were referenced by national laboratories. We carried out a deterministic and probabilistic sensitivity analysis with a third-payer perspective and a one-year horizon. Results: An ICER of USD$ 5051.10 was obtained as the incremental cost for obtaining 10.89% more probability of avoiding the birth of a child with cystic fibrosis per screened couple. For family members in second and third degrees, the ICER was USD$ 19,380.94 and USD$ 55,913.53, respectively, evidenced when applying the GDP per capita. This technology was cost-effective in 39%, 61.18%, and 74.36% for 1, 2, and 3 GDP per capita in first degree of consanguinity relatives. Conclusions: The genetic test for the detection of CFTR gene carriers was cost-effective depending on the threshold of availability to pay and the assumptions and limitations established in the model.

Introducción. La fibrosis quística es una enfermedad genética de carácter autosómico recesivo clasificada como enfermedad huérfana de alto costo. Objetivo. Determinar la razón de costo-efectividad de la prueba diagnóstica de secuenciación del gen CFTR para los portadores asintomáticos familiares en primer, segundo y tercer grados de consanguinidad. Materiales y métodos. Se hizo una búsqueda sistemática sobre la evaluación de las características operativas de la prueba diagnóstica y los modelos de árbol de decisiones en estudios de costo-efectividad. Se elaboró un modelo de árbol de decisiones tomando como unidad de análisis la prevención de futuras concepciones. Los costos de la enfermedad se obtuvieron del reporte de alto costo del Ministerio de Salud de Colombia. Los costos de la prueba se obtuvieron de laboratorios nacionales. Se hizo un análisis de sensibilidad, determinístico y probabilístico, con la perspectiva del tercer pagador y horizonte a un año. Resultados. Se obtuvo una razón incremental de costo-efectividad (RICE) de USD$5.051,10 por obtener 10,89 % más de probabilidades de evitar el nacimiento de un niño enfermo con fibrosis quística por pareja. Para los familiares de segundo y tercer grados, se encontró una RICE de USD$ 19.380,94 y USD$ 55.913,53, respectivamente, al aplicar el PIB per cápita. Esta tecnología fue costo-efectiva en 39 %, 61,18 % y 74,36 % para 1, 2 y 3 PIB per cápita en familiares de primer grado de consanguinidad. Conclusiones. La prueba genética de detección de portadores del gen CFTR resultó costo-efectiva dependiendo del umbral de la disponibilidad de pagar, y de los supuestos y limitaciones establecidas en el modelo.

Universal strategy for preimplantation genetic testing for cystic fibrosis based on next generation sequencing.

PURPOSE: We developed and applied a universal strategy for preimplantation genetic testing for all cystic fibrosis gene mutations (PGT-CF) based on next-generation sequencing (NGS). METHODS: A molecular protocol was designed to diagnose all CF mutations at preimplantation stage. The detection of CF mutations was performed by direct gene sequencing and linkage strategy testing 38 specific SNPs located upstream and inside the gene for PGT-CF. Seventeen couples at risk of CF transmission decided to undergo PGT-CF. Trophectoderm cell biopsies were performed on day 5-6 blastocysts. PGT for aneuploidy (PGT-A) was performed from the same samples. Tested embryos were transferred on further natural cycles. RESULTS: PGT was performed on 109 embryos. Fifteen CF mutations were tested. PGT-CF and PGT-A were conclusive for respectively 92.7% and 95.3% of the samples. A mean of 24.1 SNPs was informative per couple. After a single embryo transfer on natural cycle, 81.3% of the transferred tested embryos were implanted. CONCLUSIONS: The present protocol based on the entire CFTR gene together with informative SNPs outside and inside the gene can be applied to diagnose all CF mutations at preimplantation stage.

Impact of genetic testing and family health history of cystic fibrosis in the early prenatal diagnosis and prevention of a new case of genetic disorder.

Cystic fibrosis (CF) is a multi-system autosomal recessive disorder, results of mutations in the CF transmembrane conductance regulator (CFTR) gene, located on the long arm of chromosome 7. We present a special family couple with particular medical history of CF, who comes to our Clinic for genetic tests and a prenatal genetic counseling, to prevent the birth of a new affected CF child. Genetic analysis showed that the first affected child, a daughter, is compound heterozygous for two clinically significant recessive mutations: c.1521_1523delCTT; p.Phe508del, inherited from her mother, who carries the same CFTR mutation, and c.1853_1863delTTTTGCATGAA; p.IIe618Argfs 2, inherited from her father, who is heterozygous, healthy carrier, for the same CFTR mutation. In our case report, early prenatal genetic testing, pre- and post-test genetic counseling was crucial in the management of the present pregnancy, to prevent the birth of a new affected CF child.

Fibrosis quística en niños y su seguimiento durante 40 años 1977-2017) / Cystic Fibrosis in children and its follow up during 40 years (1977-2017)

Introducción: Los enfermos de fibrosis quística tienen mayor supervivencia y calidad de vida en las últimas décadas, debido fundamentalmente a un diagnóstico precoz. Objetivo: Describir las características de los pacientes con fibrosis quística y el seguimiento de los vivos durante 40 años. Métodos: Estudio descriptivo longitudinal retrospectivo en 96 pacientes diagnosticados con fibrosis quística en el Hospital Pediátrico Universitario William Soler (1977-2017). Los datos se obtuvieron de las historias clínicas. Se analizaron variables demográficas, temporales, clínicas, genéticas y microbiológicas. Resultados: De la muestra, actualmente se mantienen con seguimiento 27, mayores de 19 años enviados a consulta de neumología 9, fallecieron 30, no se siguen en el centro 30. El 60,4 por ciento se diagnosticó antes del primer año de vida, predominó el sexo masculino 62,5 por ciento y el color de la piel blanco 88,5 por ciento. Sugirió el diagnóstico la forma clínica respiratoria 39,6 por ciento, mixta 38,5 por ciento, digestiva 19,8 por ciento y perdedora de sal 2,1 por ciento. De los 27 casos seguidos actualmente 74,1 por ciento son eutróficos y no hay desnutridos. En el primer aislamiento microbiológico predominó la Pseudomona aeruginosa en el menor de 1 año y el Staphilococcus aureus entre 1 y 4 años. Más del 37.0 por ciento tuvo complicaciones respiratorias, el 14,8 por ciento hepática y el 40,7 por ciento sin complicaciones. La caracterización genética fue mayormente ∆F508 (70,3 por ciento). Conclusiones: Es frecuente el aislamiento de Pseudomona aeruginosa en el menor de 1 año. Casi la mitad de los pacientes no tienen complicaciones, se consiguió mejorar el estado nutricional y disminuir la mortalidad(AU)

Introduction: Patients with cystic fibrosis have had a greater survival and life quality in the last decades; this is due to a precocious diagnostic, a better nutrition state, and diminution of respiratory infections. Objective: To describe the characteristics of cystic fibrosis patients and follow up process to survivors for the last 40 years. Methods: Descriptive, longitudinal and retrospective study in 96 patients diagnosed with cystic fibrosis in William Soler Pediatric University Hospital (1977-2017). Data was obtained from clinical records. Demographic, temporary, clinical, genetic and microbiological variables were analized. Results: From the sample, 27 patients keep under medical follow up; 9 patients older than 19 years old were remitted to the Neumology consultation; 30 died; and 30 patients are not followed up at the hospital. 60.4 percent of the patients was diagnosed before the first year of life, t was predominant the male sex (62.5 percent) and most of them were white skin (88.5 percent). Diagnosis suggested; the respiratory clinical symptoms, 39.6 percent; mixed, 38.5 percent; digestive symptoms, 19.8 percent; salt lost, 2.1 percent. Out of the 27 cases followed at present, 74.1 percent are eutrophics, and there are not patients with malnutrition. In the first microbiological isolation, Pseudomonas aeruginosa prevailed in patients under 1-year-old and Staphilococcus aureus in patients between 1 and 4 years old. More than 37.0 percent of patients had respiratory complications, 14.8 percent had hepatic complications, and 40.7 percent had no complications. The genetic characterization was mostly of ∆F508 (59.2 percent). Conclusions: Pseudomonas aeruginosa is frequently in patients under 1-year-old. Almost half of the patients has no complications; and it is improved their nutritional state and mortality decreased(AU)

Lentiviral Vectors for the Treatment and Prevention of Cystic Fibrosis Lung Disease.

Despite the continued development of cystic fibrosis transmembrane conductance regulator (CFTR) modulator drugs for the treatment of cystic fibrosis (CF), the need for mutation agnostic treatments remains. In a sub-group of CF individuals with mutations that may not respond to modulators, such as those with nonsense mutations, CFTR gene transfer to airway epithelia offers the potential for an effective treatment. Lentiviral vectors are well-suited for this purpose because they transduce nondividing cells, and provide long-term transgene expression. Studies in primary cultures of human CF airway epithelia and CF animal models demonstrate the long-term correction of CF phenotypes and low immunogenicity using lentiviral vectors. Further development of CF gene therapy requires the investigation of optimal CFTR expression in the airways. Lentiviral vectors with improved safety features have minimized insertional mutagenesis safety concerns raised in early clinical trials for severe combined immunodeficiency using γ-retroviral vectors. Recent clinical trials using improved lentiviral vectors support the feasibility and safety of lentiviral gene therapy for monogenetic diseases. While work remains to be done before CF gene therapy reaches the bedside, recent advances in lentiviral vector development reviewed here are encouraging and suggest it could be tested in clinical studies in the near future.

Preventive Inhalation of Hypertonic Saline in Infants with Cystic Fibrosis (PRESIS). A Randomized, Double-Blind, Controlled Study.

Rationale: Cystic fibrosis (CF) lung disease starts in early infancy, suggesting that preventive treatment may be most beneficial. Lung clearance index (LCI) and chest magnetic resonance imaging (MRI) have emerged as promising endpoints of early CF lung disease; however, randomized controlled trials testing the safety and efficacy of preventive therapies in infants with CF are lacking. Objectives: To determine the feasibility, safety, and efficacy of preventive inhalation with hypertonic saline (HS) compared with isotonic saline (IS) in infants with CF, including LCI and MRI as outcome measures. Methods: In this randomized, double-blind, controlled trial, 42 infants with CF less than 4 months of age were randomized across five sites to twice-daily inhalation of 6% HS (n = 21) or 0.9% IS (n = 21) for 52 weeks. Measurements and Main Results: Inhalation of HS and IS was generally well tolerated by infants with CF, and the number of adverse events did not differ between groups (P = 0.49). The change in LCI from baseline to Week 52 was larger in infants with CF treated with HS (-0.6) than in those treated with IS (-0.1; P < 0.05). In addition, weight gain was improved in infants with CF treated with HS (P < 0.05), whereas pulmonary exacerbations and chest MRI scores did not differ in the HS group versus the IS group. Conclusions: Preventive inhalation with HS initiated in the first months of life was safe and well tolerated and resulted in improvements in LCI and weight gain in infants with CF. Our results support the feasibility of LCI as an endpoint in randomized controlled trials in infants with CF. Clinical trial registered with www.clinicaltrials.gov (NCT01619657).

Expanded carrier screening and preimplantation genetic diagnosis in a couple who delivered a baby affected with congenital factor VII deficiency.

BACKGROUND: Preimplantation genetic diagnosis (PGD) is a powerful tool for preventing the transmission of Mendelian disorders from generation to generation. However, PGD only can identify monogenically inherited diseases, but not other potential monogenic pathologies. We aimed to use PGD to deliver a healthy baby without congenital FVII deficiency or other common Mendelian diseases in a couple in which both individuals carried a deleterious mutation in the F7 gene. METHODS: After both members of the couple were confirmed to be carriers of the F7 gene mutation by Sanger sequencing, expanded carrier screening (ECS) for 623 recessive inheritance diseases was performed to detect pathological mutations in other genes. PGD and preimplantational genetic screening (PGS) were employed to exclude monogenic disorders and aneuploidy for their embryos. RESULTS: ECS using targeted capture sequencing technology revealed that the couple carried the heterozygous disease-causative mutations c.3659C > T (p.Thr1220Ile) and c.3209G > A (p.Arg1070Gln) in the CFTR gene. After PGD and PGS, one of their embryos that was free of congenital FVII deficiency, cystic fibrosis (CF) and aneuploidy was transferred, resulting in the birth of a healthy 3200 g male infant. CONCLUSION: We successfully implemented PGD for congenital FVII deficiency and PGD after ECS to exclude CF for the first time to the best of our knowledge. Our work significantly improved the reproductive outcome for the couple and provides a clear example of the use of ECS combined with PGD to avoid the delivery of offspring affected not only by identified monogenically inherited diseases but also by other potential monogenic pathologies and aneuploidy.

Psychosocial Distress and Knowledge Deficiencies in Parents of Children in Ireland Who Carry an Altered Cystic Fibrosis Gene.

Significant gaps have been identified in parental understanding of CF newborn screening and the consequences of carrying an altered CF gene. Seven potential causes of psychosocial adversity arising from false positive newborn screening for CF have been identified. The current study aimed to increase parents understanding of CF, reduce their levels of stress, and investigate psychosocial adversity arising from false-positive screening. This national study was run over one year in the Republic of Ireland. Parents were recruited for the study following a diagnostic sweat test confirming their child carried a single altered CF gene. Parents were randomly assigned into a control and intervention group, with those in the intervention group receiving a carefully designed information pack. All parents took part in semi-structured interviews. Parents (n = 16) who received an information pack had significantly higher CF knowledge scores than parents (n = 16) in the control group. 66% of parents in the control group misunderstood the health implications of carrying an altered CF gene, no parents in the intervention group had the same misunderstanding. There was no significant difference in stress scores between the groups. Parents of infants who had more than one sweat test due to insufficient sweat quantity had higher overall stress percentiles (50%), than parents of infants who had one sweat test (30%), indicating greater parental stress. The combination of written and audio-visual information contained in the information pack successfully increased parents comprehension of CF. The study also evaluates the potential for psychosocial adversity following false positive newborn screening for CF.

The Mist Tent: An Analysis of Therapeutic Change in the History of Cystic Fibrosis Care.

Mist tent therapy for cystic fibrosis went through a rise and fall in popularity between the 1950s and 1970s, providing an opportunity to explore the nature of therapeutic change in medicine. The therapy "worked" in the context of a particularly grim life expectancy in the early 1950s and in the setting of a comprehensive therapeutic program that began in Cleveland in 1957. Although clinical studies published in the 1970s provided evidence that mist tents were ineffective or even harmful, these later studies were not necessarily more robust than earlier studies that provided evidence of mist tent efficacy, suggesting that other factors may have also contributed to mist tent abandonment. In fact, the unpalatable nature of mist tent therapy, which was described by one doctor as akin to incarceration, and studies that questioned the theoretical underpinnings of the therapy also played important roles in the eventual abandonment of mist tents.

Sweat test and cystic fibrosis: overview of test performance at public and private centers in the state of São Paulo, Brazil.

OBJECTIVE:: The sweat test (ST) measures chloride levels in sweat and is considered the gold standard for the diagnosis of cystic fibrosis (CF). However, the reliability of a ST depends on their being performed by experienced technicians and in accordance with strict guidelines. Our aim was to evaluate how sweat stimulation, sweat collection, and chloride measurement are performed at 14 centers (9 public centers and 5 private centers) that routinely perform STs in the state of São Paulo, which has the highest frequency of CF in Brazil. METHODS:: This was a cross-sectional cohort study, using a standardized questionnaire administered in loco to the staff responsible for conducting STs. RESULTS:: No uniformity regarding the procedures was found among the centers. Most centers were noncompliant with the international guidelines, especially regarding the collection of sweat (the samples were insufficient in 10-50% of the subjects tested); availability of stimulation equipment (which was limited at 2 centers); modernity and certification of stimulation equipment (most of the equipment having been used for 3-23 years); and written protocols (which were lacking at 12 centers). Knowledge of ST guidelines was evaluated at only 1 center. CONCLUSIONS:: Our results show that STs largely deviate from internationally accepted guidelines at the participating centers. Therefore, there is an urgent need for standardization of STs, training of qualified personnel, and acquisition/certification of suitable equipment. These are essential conditions for a reliable diagnosis of CF, especially with the increasing demand due to newborn screening nationwide, and for the assessment of a possible clinical benefit from the use of modulator drugs. OBJETIVO:: O teste do suor (TS) mede os níveis de cloro no suor e é considerado o padrão ouro para o diagnóstico da fibrose cística (FC). Contudo, a confiabilidade do TS depende de sua realização por técnicos experientes e segundo diretrizes rígidas. Nosso objetivo foi avaliar como são realizadas a estimulação e coleta do suor e a dosagem de cloro em 14 centros (9 públicos e 5 privados) que realizam TS rotineiramente no estado de São Paulo, que possui a maior frequência de FC do Brasil. MÉTODOS:: Estudo de coorte transversal utilizando um questionário padronizado aplicado in loco ao pessoal responsável pela realização dos TS. RESULTADOS:: Não houve uniformidade entre os centros quanto aos procedimentos. A maioria dos centros não era aderente às diretrizes internacionais, especialmente quanto à coleta do suor (amostras insuficientes em 10-50% dos indivíduos testados), disponibilidade de equipamentos de estimulação (limitada em 2 centros), modernidade e certificação dos mesmos (a maioria utilizada há 3-23 anos) e protocolos escritos (ausentes em 12 centros). Avaliou-se o conhecimento sobre diretrizes para TS em apenas 1 centro. CONCLUSÕES:: Nossos resultados mostram que, nos centros participantes, os TS estão muito distantes das diretrizes internacionalmente aceitas. Portanto, há necessidade urgente de padronização dos TS, de treinamento de pessoal qualificado e de aquisição/certificação de equipamentos adequados. Essas são condições essenciais para um diagnóstico confiável de FC, especialmente com a crescente demanda resultante da triagem neonatal em todo o país, e para a avaliação do possível benefício clínico do uso de moduladores.

[Newborn Screening on Cystic Fibrosis in Germany: Comparison of the new Screening Protocol with an Alternative Protocol]. / Neugeborenenscreening auf Mukoviszidose in Deutschland: Vergleich des neuen Screening-Protokolls mit einem Alternativprotokoll.

Background For the new cystic fibrosis (CF) newborn screening program in Germany the Federal Joint Committee (G-BA) implemented a new screening protocol using immunoreactive trypsinogen (IRT) as first and pancreatitis associated protein (PAP) as second tier. Gene analysis with a panel of 31 CFTR-mutations is used as third tier to increase the positive predictive value (PPV) which is known to be low in pure biochemical IRT/PAP protocols. Methods For post hoc analysis the data pool (n=372 906) of a study evaluating a pure biochemical IRT/PAP protocol was used for assessment of the 3-step G-BA protocol in comparison with an alternative screening protocol recommended by the authors. The difference between the 2 protocols is the procedure when IRT>99.9th percentile. In the G BA protocol PAP and DNA analysis will be by-passed while in the alternative protocol only the PAP step will be circumvented. Results Both 3-tier IRT/PAP+SN/DNA protocols did not lose sensitivity due to addition of genetic analysis when the results were compared to those of the 2-tier biochemical IRT/PAP protocol. However, the protocols provide different results regarding PPV. The G-BA protocol showed with 351 a much higher number of false-positively detected newborns (PPV 20.2%) when compared to 31 false-positively detected newborns in the alternative protocol (PPV 69.6%). Conclusions The G-BA protocol had a worse performance when compared with the alternative protocol recommended by the authors. The higher number of false-positively detected newborns using the G-BA protocol will lead to more consultations including sweat tests, will create more anxiety in parents, and will result in higher costs after screening.

Sweat test and cystic fibrosis: overview of test performance at public and private centers in the state of São Paulo, Brazil / Teste do suor e fibrose cística: panorama da realização do teste em centros públicos e privados do estado de São Paulo

ABSTRACT Objective: The sweat test (ST) measures chloride levels in sweat and is considered the gold standard for the diagnosis of cystic fibrosis (CF). However, the reliability of a ST depends on their being performed by experienced technicians and in accordance with strict guidelines. Our aim was to evaluate how sweat stimulation, sweat collection, and chloride measurement are performed at 14 centers (9 public centers and 5 private centers) that routinely perform STs in the state of São Paulo, which has the highest frequency of CF in Brazil. Methods: This was a cross-sectional cohort study, using a standardized questionnaire administered in loco to the staff responsible for conducting STs. Results: No uniformity regarding the procedures was found among the centers. Most centers were noncompliant with the international guidelines, especially regarding the collection of sweat (the samples were insufficient in 10-50% of the subjects tested); availability of stimulation equipment (which was limited at 2 centers); modernity and certification of stimulation equipment (most of the equipment having been used for 3-23 years); and written protocols (which were lacking at 12 centers). Knowledge of ST guidelines was evaluated at only 1 center. Conclusions: Our results show that STs largely deviate from internationally accepted guidelines at the participating centers. Therefore, there is an urgent need for standardization of STs, training of qualified personnel, and acquisition/certification of suitable equipment. These are essential conditions for a reliable diagnosis of CF, especially with the increasing demand due to newborn screening nationwide, and for the assessment of a possible clinical benefit from the use of modulator drugs.

RESUMO Objetivo: O teste do suor (TS) mede os níveis de cloro no suor e é considerado o padrão ouro para o diagnóstico da fibrose cística (FC). Contudo, a confiabilidade do TS depende de sua realização por técnicos experientes e segundo diretrizes rígidas. Nosso objetivo foi avaliar como são realizadas a estimulação e coleta do suor e a dosagem de cloro em 14 centros (9 públicos e 5 privados) que realizam TS rotineiramente no estado de São Paulo, que possui a maior frequência de FC do Brasil. Métodos: Estudo de coorte transversal utilizando um questionário padronizado aplicado in loco ao pessoal responsável pela realização dos TS. Resultados: Não houve uniformidade entre os centros quanto aos procedimentos. A maioria dos centros não era aderente às diretrizes internacionais, especialmente quanto à coleta do suor (amostras insuficientes em 10-50% dos indivíduos testados), disponibilidade de equipamentos de estimulação (limitada em 2 centros), modernidade e certificação dos mesmos (a maioria utilizada há 3-23 anos) e protocolos escritos (ausentes em 12 centros). Avaliou-se o conhecimento sobre diretrizes para TS em apenas 1 centro. Conclusões: Nossos resultados mostram que, nos centros participantes, os TS estão muito distantes das diretrizes internacionalmente aceitas. Portanto, há necessidade urgente de padronização dos TS, de treinamento de pessoal qualificado e de aquisição/certificação de equipamentos adequados. Essas são condições essenciais para um diagnóstico confiável de FC, especialmente com a crescente demanda resultante da triagem neonatal em todo o país, e para a avaliação do possível benefício clínico do uso de moduladores.

Guía clínica fibrosis quística / Cystic fibrosis clinical guide

La Fibrosis Quística (FQ) es la enfermedad autosómica recesiva letal más frecuente en raza blanca. Se transmite de manera autosómica recesiva. Este patrón de herencia implica que una pareja de portadores tiene una probabilidad de 25% de tener un hijo con FQ en cada embarazo. En Chile, de acuerdo con la mezcla racial existente y los estudios de las mutaciones, se estima una incidencia aproximada de 1/6.000 a 1/8.000 recién nacidos vivos, lo que significa aproximadamente 40-50 casos nuevos anuales. 1 de cada 32 personas sanas serían portadoras (1,2) La enfermedad se produce por mutaciones en el gen que codifica para la proteína reguladora de conductancia de transmembrana de la FQ (CFTR), ubicado en el brazo largo del cromosoma 7. A la fecha, se han encontrado más de 2000 mutaciones que la causan, siendo la más común la llamada pF508del. El defecto de la proteína CFTR provoca un trastorno del transporte de cloro y sodio por las células de los epitelios. La alteración de la función del canal de cloro lleva a la deshidratación de las secreciones de las glándulas exocrinas de las vías respiratorias, páncreas, intestino, vasos deferentes, y a la eliminación de sudor con altas concentraciones de cloro y sodio.

Endoplasmic Reticulum-Targeted Subunit Toxins Provide a New Approach to Rescue Misfolded Mutant Proteins and Revert Cell Models of Genetic Diseases.

Many germ line diseases stem from a relatively minor disturbance in mutant protein endoplasmic reticulum (ER) 3D assembly. Chaperones are recruited which, on failure to correct folding, sort the mutant for retrotranslocation and cytosolic proteasomal degradation (ER-associated degradation-ERAD), to initiate/exacerbate deficiency-disease symptoms. Several bacterial (and plant) subunit toxins, retrograde transport to the ER after initial cell surface receptor binding/internalization. The A subunit has evolved to mimic a misfolded protein and hijack the ERAD membrane translocon (dislocon), to effect cytosolic access and cytopathology. We show such toxins compete for ERAD to rescue endogenous misfolded proteins. Cholera toxin or verotoxin (Shiga toxin) containing genetically inactivated (± an N-terminal polyleucine tail) A subunit can, within 2-4 hrs, temporarily increase F508delCFTR protein, the major cystic fibrosis (CF) mutant (5-10x), F508delCFTR Golgi maturation (<10x), cell surface expression (20x) and chloride transport (2x) in F508del CFTR transfected cells and patient-derived F508delCFTR bronchiolar epithelia, without apparent cytopathology. These toxoids also increase glucocerobrosidase (GCC) in N370SGCC Gaucher Disease fibroblasts (3x), another ERAD-exacerbated misfiling disease. We identify a new, potentially benign approach to the treatment of certain genetic protein misfolding diseases.

Carrier Screening is a Deficient Strategy for Determining Sperm Donor Eligibility and Reducing Risk of Disease in Recipient Children.

AIMS: DNA-based carrier screening is a standard component of donor eligibility protocols practiced by U.S. sperm banks. Applicants who test positive for carrying a recessive disease mutation are typically disqualified. The aim of our study was to examine the utility of a range of screening panels adopted by the industry and the effectiveness of the screening paradigm in reducing a future child's risk of inheriting disease. METHODS: A cohort of 27 donor applicants, who tested negative on an initial cystic fibrosis carrier test, was further screened with three expanded commercial carrier testing panels. These results were then compared to a systematic analysis of the applicants' DNA using next-generation sequencing (NGS) data. RESULTS: The carrier panels detected serious pediatric disease mutations in one, four, or six donor applicants. Because each panel screens distinct regions of the genome, no single donor was uniformly identified as carrier positive by all three panels. In contrast, systematic NGS analysis identified all donors as carriers of one or more mutations associated with severe monogenic pediatric disease. These included 30 variants classified as "pathogenic" based on clinical observation and 66 with a high likelihood of causing gene dysfunction. CONCLUSION: Despite tremendous advances in variant identification, understanding, and analysis, the vast majority of disease-causing mutation combinations remain undetected by commercial carrier screening panels, which cover a narrow, and often distinct, subset of genes and mutations. The biological reality is that all donors and recipients carry serious recessive disease mutations. This challenges the utility of any screening protocol that anchors donor eligibility to carrier status. A more effective approach to reducing recessive disease risk would consider joint comprehensive analysis of both donor and recipient disease mutations. This type of high-resolution recessive disease risk analysis is now available and affordable, but industry practice must be modified to incorporate its use.

Deficiencia de vitamina A en niños con fibrosis quística / Vitamin A deficiency in children with cystic fibrosis

INTRODUCCIÓN: la carencia subclínica de vitamina A es frecuente en niños y adolescentes con fibrosis quística, y tiene un origen multifactorial; contribuye al deterioro pulmonar y ensombrece el pronóstico de la enfermedad. OBJETIVO: caracterizar el estado de esta vitamina en niños y adolescentes fibroquísticos y su relación con el estado nutricional y algunas variables clínicas. MÉTODOS: se realizó un estudio descriptivo, transversal (año 2014), de los 11 pacientes menores de 18 años atendidos en consulta multidisciplinaria del Hospital Pediátrico Centro Habana, que recibían suplementos diarios de vitamina A, como parte de la recomendación dietética y que se encontraban estables de su enfermedad, sin síntomas carenciales. Se evaluó el nivel de retinol sérico por cromatografía de alta resolución y se consideraron valores normales, según la OMS, entre 30 y 79 µg/dL, marginales entre 20 y < 30 µg/dL y deficiencia subclínica entre 10 y < 20 µg/dL. El estado nutricional se evaluó según percentil de índice de masa corporal, correspondiente a la población cubana según edad decimal y sexo. Se clasificó, además, a los enfermos, según mutación reportada, presencia de insuficiencia pancreática y enfermedad pulmonar típica, de acuerdo con registros clínicos. RESULTADOS: en la muestra predominó la mutación del 508F (2 homocigotos y 6 heterocigotos) y la enfermedad típica con insuficiencia pancreática (10 de 11). En 7 niños (63,6 %) se detectaron niveles bajos de vitamina A (4 marginales y 3 deficientes), con predominio en niños con bajo peso (80 vs. 50 % en los eutróficos), prescolares (2 de 2) y adolescentes (3 de 5). CONCLUSIONES: es importante el monitoreo de esta vitamina en el seguimiento de los enfermos de fibrosis quística.

INTRODUCTION: subclinical Vitamin A deficiency is common in children and adolescents with cystic fibrosis of multifactoral origin; it influences the pulmonary deterioration and casts a shadow over the disease prognosis. OBJECTIVE: to characterize the state of this vitamin in children and adolescents with cystic fibrosis and its association with the nutritional status and with some clinical variables. METHODS: a cross-sectional and descriptive study was conducted in younger than 18 years-old children. They were seen at the multidisciplinary service of Centro Habana pediatric hospital, and received daily Vitamin A supplements as part of dietary recommendations; they were stable with no symptoms of shortage at the time of study. A high resolution chromatography evaluated the level of serum retinol, whose values, according to WHO standards, were considered normal when yielding 30-79 µg/dL, marginal from 20 to less than 30 µg/dL and subclinical deficiency ranging from 10 to lower than 20 µg/dL. The nutritional status was measured as body mass index percentiles of the Cuban population by decimal age and sex. Additionally, the patients were classified on the basis of reported mutation, pancreatic deficiency and typical pulmonary disease pursuant to the medical histories. RESULTS: in the sample, the 508F mutation (2 homozygotic and 6 heterozygotic) and typical disease with pancreatic disease (10) prevailed. Seven children (63.2 %) had low Vitamin A levels (4 marginal and 3 deficient), being low weighed children (80 vs. 50 % in the eutrophic ones), preschool children (2 out of 2) and adolescents (3 out of 5) predominant. CONCLUSIONS: it is important to monitor Vitamin A in the follow-up of patients with cystic fibrosis.

"Suddenly Having two Positive People who are Carriers is a Whole New Thing" - Experiences of Couples Both Identified as Carriers of Cystic Fibrosis Through a Population-Based Carrier Screening Program in Australia.

A population-based CF carrier screening program was implemented in Victoria, Australia in 2006. This study explored the experiences of couples when both partners were identified as CF carriers. Between January 2006 and December 2010, 10 carrier couples were identified and invited to undertake a semi-structured interview. Nine interviews were conducted, seven couple interviews and two individual interviews. One couple declined to participate due to the recent termination of an affected pregnancy. Interviews were analyzed using inductive content analysis. All couples experienced surprise on learning their carrier couple result. The couples who were pregnant at the time of screening chose to have prenatal diagnosis, with the majority considering it to be the "next step." The two couples who had an affected pregnancy reported feelings of devastation and grief upon receiving their prenatal diagnosis result and terminated the pregnancy. All carrier couples were offered free genetic counseling, with only one couple declining the offer. Couples were unprepared for a positive carrier couple result. However, all the couples changed their reproductive behavior as a result of their carrier status. The results of this study have been used to inform the program and service offered to CF carrier couples particularly with respect to genetic counseling for reproductive decision making.