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Kay DM, Sadeghi H, Kier C, Berdella M, DeCelie-Germana JK, Soultan ZN, Goetz DM, Caggana M, Fortner CN, Giusti R, Kaslovsky R, Stevens C, Voter K, Welter JJ, Langfelder-Schwind E. Genetic counseling access and service delivery in New York State is variable for parents of infants with complex CFTR genotypes conferring uncertain phenotypes. Pediatr Pulmonol 2024; 59:1952-1961. [PMID: 38695616 DOI: 10.1002/ppul.27023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 02/26/2024] [Accepted: 04/10/2024] [Indexed: 07/21/2024]
Abstract
BACKGROUND New York State (NYS) utilizes a three-tiered cystic fibrosis newborn screening (CFNBS) algorithm that includes cystic fibrosis transmembrane conductance regulator (CFTR) gene sequencing. Infants with >1 CFTR variant of potential clinical relevance, including variants of uncertain significance or varying clinical consequence are referred for diagnostic evaluation at NYS cystic fibrosis (CF) Specialty Care Centers (SCCs). AIMS As part of ongoing quality improvement efforts, demographic, screening, diagnostic, and clinical data were evaluated for 289 CFNBS-positive infants identified in NYS between December 2017 and November 2020 who did not meet diagnostic criteria for CF and were classified as either: CFTR-related metabolic syndrome/CF screen positive, inconclusive diagnosis (CRMS/CFSPID) or CF carriers. RESULTS Overall, 194/289 (67.1%) had CFTR phasing to confirm whether the infant's CFTR variants were in cis or in trans. Eighteen complex alleles were identified in cis; known haplotypes (p.R117H+5T, p.F508del+p.L467F, and p.R74W+p.D1270N) were the most common identified. Thirty-two infants (16.5%) with all variants in cis were reclassified as CF carriers rather than CRMS/CFSPID. Among 263 infants evaluated at an NYS SCC, 70.3% were reported as having received genetic counseling about their results by any provider, with 96/263 (36.5%) counseled by a certified genetic counselor. CONCLUSION Given the particularly complex genetic interpretation of results generated by CFNBS algorithms including sequencing analysis, additional efforts are needed to ensure families of infants with a positive CFNBS result have CFTR phasing when needed to distinguish carriers from infants with CRMS/CFSPID, and access to genetic counseling to address implications of CFNBS results.
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Affiliation(s)
- Denise M Kay
- Newborn Screening Program, Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Hossein Sadeghi
- Columbia University Irving Medical Center, New York City, New York, USA
| | - Catherine Kier
- Department of Pediatrics, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York, USA
| | - Maria Berdella
- Lenox Hill Hospital, Northwell Health System, New York City, New York, USA
| | | | - Zafer N Soultan
- Division of Pediatric Pulmonary Medicine, Department of Pediatrics, Upstate Medical University, Syracuse, New York, USA
| | | | - Michele Caggana
- Newborn Screening Program, Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Christopher N Fortner
- Division of Pediatric Pulmonary Medicine, Department of Pediatrics, Upstate Medical University, Syracuse, New York, USA
| | | | - Robert Kaslovsky
- Department of Pediatrics, Albany Medical College, Albany, New York, USA
| | - Colleen Stevens
- Newborn Screening Program, Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Karen Voter
- Strong Memorial Hospital, University of Rochester Medical Center, Rochester, New York, USA
| | - John J Welter
- Division of Pediatric Pulmonology, New York Medical College, Valhalla, New York, USA
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2
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Tory K. The dominant findings of a recessive man: from Mendel's kid pea to kidney. Pediatr Nephrol 2024; 39:2049-2059. [PMID: 38051388 PMCID: PMC11147900 DOI: 10.1007/s00467-023-06238-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 11/07/2023] [Accepted: 11/15/2023] [Indexed: 12/07/2023]
Abstract
The research of Mendel, born two centuries ago, still has many direct implications for our everyday clinical work. He introduced the terms "dominant" and "recessive" characters and determined their 3:1 ratio in the offspring of heterozygous "hybrid" plants. This distribution allowed calculation of the number of the phenotype-determining "elements," i.e., the alleles, and has been used ever since to prove the monogenic origin of a disorder. The Mendelian inheritance of monogenic kidney disorders is still of great help in distinguishing them from those with multifactorial origin in clinical practice. Inheritance of most monogenic kidney disorders fits to Mendel's observations: the equal contribution of the two parents and the complete penetrance or the direct correlation between the frequency of the recessive character and the degree of inbreeding. Nevertheless, beyond the truth of these basic concepts, several observations have expanded their genetic characteristics. The extreme genetic heterogeneity, the pleiotropy of the causal genes and the role of modifiers in ciliopathies, the digenic inheritance and parental imprinting in some tubulopathies, and the incomplete penetrance and eventual interallelic interactions in podocytopathies, reflect this expansion. For all these reasons, the transmission pattern in a natural setting may depend not only on the "character" but also on the causal gene and the variant. Mendel's passion for research combined with his modest personality and meticulous approach can still serve as an example in the work required to understand the non-Mendelian universe of genetics.
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Affiliation(s)
- Kálmán Tory
- MTA-SE Lendület Nephrogenetic Laboratory, Hungarian Academy of Sciences, Budapest, Hungary.
- Pediatric Center, MTA Center of Excellence, Semmelweis University, Budapest, Hungary.
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Schmidt RJ, Steeves M, Bayrak-Toydemir P, Benson KA, Coe BP, Conlin LK, Ganapathi M, Garcia J, Gollob MH, Jobanputra V, Luo M, Ma D, Maston G, McGoldrick K, Palculict TB, Pesaran T, Pollin TI, Qian E, Rehm HL, Riggs ER, Schilit SLP, Sergouniotis PI, Tvrdik T, Watkins N, Zec L, Zhang W, Lebo MS. Recommendations for risk allele evidence curation, classification, and reporting from the ClinGen Low Penetrance/Risk Allele Working Group. Genet Med 2024; 26:101036. [PMID: 38054408 PMCID: PMC10939896 DOI: 10.1016/j.gim.2023.101036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 11/28/2023] [Accepted: 11/30/2023] [Indexed: 12/07/2023] Open
Abstract
PURPOSE Genetic variants at the low end of the penetrance spectrum have historically been challenging to interpret because their high population frequencies exceed the disease prevalence of the associated condition, leading to a lack of clear segregation between the variant and disease. There is currently substantial variation in the classification of these variants, and no formal classification framework has been widely adopted. The Clinical Genome Resource Low Penetrance/Risk Allele Working Group was formed to address these challenges and promote harmonization within the clinical community. METHODS The work presented here is the product of internal and community Likert-scaled surveys in combination with expert consensus within the Working Group. RESULTS We formally recognize risk alleles and low-penetrance variants as distinct variant classes from those causing highly penetrant disease that require special considerations regarding their clinical classification and reporting. First, we provide a preferred terminology for these variants. Second, we focus on risk alleles and detail considerations for reviewing relevant studies and present a framework for the classification these variants. Finally, we discuss considerations for clinical reporting of risk alleles. CONCLUSION These recommendations support harmonized interpretation, classification, and reporting of variants at the low end of the penetrance spectrum.
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Affiliation(s)
- Ryan J Schmidt
- Children's Hospital Los Angeles, Keck School of Medicine of USC, Los Angeles, CA.
| | | | - Pinar Bayrak-Toydemir
- Department of Pathology, University of Utah Molecular Genetics and Genomics, ARUP Laboratories, Salt Lake City, UT
| | - Katherine A Benson
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, Ireland
| | - Bradley P Coe
- Department of Pathology & Lab Medicine, BC Children's & BC Women's Hospitals, Vancouver, Canada
| | - Laura K Conlin
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA; Division of Genomic Diagnostics, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Mythily Ganapathi
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY
| | | | - Michael H Gollob
- Inherited Arrhythmia and Cardiomyopathy Program, Division of Cardiology, Toronto General Hospital and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Vaidehi Jobanputra
- New York Genome Center, New York, NY; Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY
| | - Minjie Luo
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA; Division of Genomic Diagnostics, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Deqiong Ma
- DNA diagnostic lab, Department of Genetics, School of Medicine, Yale University, New Haven, CT
| | | | | | | | | | - Toni I Pollin
- University of Maryland School of Medicine, Baltimore, MD
| | - Emily Qian
- Department of Genetics, Yale University School of Medicine, New Haven, CT
| | - Heidi L Rehm
- Center for Genomics Medicine, Massachusetts General Hospital, Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA
| | - Erin R Riggs
- Geisinger Autism & Developmental Medicine Institute, Lewisburg, PA
| | - Samantha L P Schilit
- Mass General Brigham, Brigham and Woman's Hospital, Harvard Medical School, Boston, MA
| | | | - Tatiana Tvrdik
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA
| | - Nicholas Watkins
- Department of Pathology and Laboratory Medicine, Sinai Health System, Toronto, Ontario, Canada Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | | | - Wenying Zhang
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH
| | - Matthew S Lebo
- Mass General Brigham, Brigham and Woman's Hospital, Harvard Medical School, Broad Institute of MIT and Harvard, Cambridge, MA.
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Bouva MJ, Dankert-Roelse JE, van der Ploeg C, Verschoof-Puite RK, Zomer-van Ommen DD, Gille J, Jakobs BS, Heijnen M, de Winter-de Groot KM. Optimization of performance of Dutch newborn screening for cystic fibrosis. J Cyst Fibros 2024; 23:120-125. [PMID: 37716879 DOI: 10.1016/j.jcf.2023.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 09/01/2023] [Accepted: 09/01/2023] [Indexed: 09/18/2023]
Abstract
BACKGROUND Dutch newborn screening (NBS) for Cystic Fibrosis (CF) introduced in 2011 showed a sensitivity of 90% and a positive predictive value (PPV) of 63%. We describe a study including an optimization phase and evaluation of the modified protocol. METHODS Dutch protocol consists of four steps: determination of immunoreactive trypsinogen (IRT) and pancreatitis-associated protein (PAP), DNA analysis by INNO-LiPA and extended gene analysis (EGA). For the optimization phase we used results of 556,952 newborns screened between April 2011 and June 2014 to calculate effects of 13 alternative protocols on sensitivity, specificity, PPV, ratios of CF to other diagnoses, and costs. One alternative protocol was selected based on calculated sensitivity, PPV and costs and was implemented on 1st July 2016. In this modified protocol DNA analysis is performed in samples with a combination of IRT ≥60 µg/l and PAP ≥3.0 µg/l, IRT ≥100 µg/l and PAP ≥1.2 µg/l or IRT ≥124 µg/l and PAP not relevant. Results of 599,137 newborns screened between 1st July 2016 and 31st December 2019 were similarly evaluated as in the optimization phase. RESULTS The modified protocol showed a sensitivity of 95%, PPV of 76%, CF to CF transmembrane conductance regulator-related metabolic syndrome/CF screen positive, inconclusive diagnoses (CRMS/CFSPID) ratio 12/1, CF/CF carrier ratio 4/1. Costs per screened newborn were slightly higher. Eleven children, of whom five with classic CF, would not have been referred with the previous protocol. CONCLUSIONS The modified protocol results in acceptable sensitivity (95%) and good PPV of 76% with minimal increase in costs.
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Affiliation(s)
- M J Bouva
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - J E Dankert-Roelse
- Department of Pediatrics, School for Public Health and Primary Care, Maastricht University Medical Centre, Maastricht, the Netherlands
| | - Cpb van der Ploeg
- Department of Child Health, Netherlands Organisation for Applied Scientific Research (TNO), Leiden, the Netherlands
| | - R K Verschoof-Puite
- Department of Vaccine Supply and Prevention Programmes, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | | | - Jjp Gille
- Department of Clinical Genetics, VU University Medical Center, Amsterdam, the Netherlands
| | - B S Jakobs
- Department of Clinical Chemistry and Haematology, Elisabeth-TweeSteden (ETZ) Hospital, Tilburg, the Netherlands
| | - Mla Heijnen
- Centre for Population Screening, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - K M de Winter-de Groot
- Department of Paediatric Pulmonology, Wilhelmina Children's Hospital - University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
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Krasnova M, Efremova A, Bukhonin A, Zhekaite E, Bukharova T, Melyanovskaya Y, Goldshtein D, Kondratyeva E. The Effect of Complex Alleles of the CFTR Gene on the Clinical Manifestations of Cystic Fibrosis and the Effectiveness of Targeted Therapy. Int J Mol Sci 2023; 25:114. [PMID: 38203285 PMCID: PMC10779438 DOI: 10.3390/ijms25010114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/11/2023] [Accepted: 12/14/2023] [Indexed: 01/12/2024] Open
Abstract
The authors of this article analyzed the available literature with the results of studying the prevalence of complex alleles of the CFTR gene among patients with cystic fibrosis, and their pathogenicity and influence on targeted therapy with CFTR modulators. Cystic fibrosis (CF) is a multisystemic autosomal recessive disease caused by a defect in the expression of the CFTR protein, and more than 2000 genetic variants are known. Clinically significant variants are divided into seven classes. Information about the frequency of complex alleles appears in a number of registers, along with the traditional presentation of data on genetic variants. Complex alleles (those with the presence of more than two nucleotide variants on one allele) can complicate the diagnosis of the disease, and change the clinical manifestations of cystic fibrosis and the response to treatment, since each variant in the complex allele can contribute to the functional activity of the CFTR protein, changing it both in terms of increasing and decreasing function. The role of complex alleles is often underestimated, and their frequency has not been studied. At the moment, characteristic frequently encountered complex alleles have been found for several populations of patients with cystic fibrosis, but the prevalence and pathogenicity of newly detected complex alleles require additional research. In this review, more than 35 complex alleles of the CFTR gene from existing research studies were analyzed, and an analysis of their influence on the manifestations of the disease and the effectiveness of CFTR modulators was also described.
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Affiliation(s)
| | - Anna Efremova
- Research Centre for Medical Genetics, Moscow 115522, Russia; (M.K.); (A.B.); (E.Z.); (T.B.); (Y.M.); (D.G.); (E.K.)
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6
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Hu M, McLellan T, Grogono D, Karia S, Herre J. Delayed identification of compound heterozygous (Phe508del/Arg117His) cystic fibrosis variants in a patient awaiting liver transplantation. BMJ Case Rep 2023; 16:e255602. [PMID: 37989334 PMCID: PMC11107079 DOI: 10.1136/bcr-2023-255602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2023] [Indexed: 11/23/2023] Open
Abstract
A man in his 60s undergoing liver transplant assessment was referred to the respiratory team after a thoracic CT scan revealed diffuse tree-in-bud changes. He had a history of infertility, chronic pancreatitis and liver cirrhosis with portal hypertension. Broncho-alveolar lavage was positive for Pseudomonas aeruginosa Genetic screening found two cystic fibrosis transmembrane conductance regulator variants: Phe508del and Arg117His-7T. The patient was referred to the regional cystic fibrosis (CF) centre for follow-up but died from hepatobiliary complications. The atypical presentation with relatively late onset of pulmonary disease and hepatobiliary disease predominance created a diagnostic challenge. This case is a reminder that while CF is a monogenic disorder, its manifestation, natural history and extent can be highly variable. Taking a thorough medical history of any chronic illness is essential, and patients with the appropriate clinical presentation, regardless of age, should be investigated for CF.
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Affiliation(s)
- Mostin Hu
- School of Clinical Medicine, University of Cambridge, Cambridge, UK
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7
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Heston AL, Sharma V, Johnson T, Anandakrishnan A, Patel A. A Case of Severe Hepatitis in Infant Twins With COVID-19. Cureus 2023; 15:e41967. [PMID: 37588319 PMCID: PMC10427151 DOI: 10.7759/cureus.41967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2023] [Indexed: 08/18/2023] Open
Abstract
We report a case of nine-month-old twins who presented with bright green diarrhea along with progressively worsening jaundice over one week. On initial evaluation, they were found to have significantly elevated liver enzymes, bilirubin, and alkaline phosphatase levels but without signs of liver failure. They were tested for multiple causes of liver injury including autoimmune and infectious etiologies, which were negative as well. Both twins were incidentally found to be positive for COVID-19 on testing per hospital protocol but did not have any respiratory symptoms. They were monitored closely during their hospital stay and showed clinical stability but with only slight improvement in abnormal lab levels. Ultimately, they were discharged with close outpatient follow-up. They demonstrated full resolution of all lab abnormalities and symptoms two months post discharge.
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Affiliation(s)
| | - Varun Sharma
- Medicine, University of Arizona College of Medicine, Phoenix, USA
| | - Taryn Johnson
- Pediatrics, Phoenix Children's Hospital, Phoenix, USA
| | | | - Ashish Patel
- Pediatric Gastroenterology, Phoenix Children's Hospital, Phoenix, USA
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8
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Salinas DB, Ginsburg DK, Wee CP, Saeed MM, Brewington JJ. Gradual increase in sweat chloride concentration is associated with a higher risk of CRMS/CFSPID to CF reclassification. Pediatr Pulmonol 2023; 58:1074-1084. [PMID: 36582049 DOI: 10.1002/ppul.26296] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 12/10/2022] [Accepted: 12/23/2022] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Universal implementation of cystic fibrosis (CF) newborn screening (NBS) has led to the diagnostic dilemma of infants with CF screen-positive, inconclusive diagnosis (CFSPID), with limited guidance regarding prognosis and standardized care. Rates of reclassification from CFSPID to CF vary and risk factors for reclassification are not well established. We investigated whether clinical characteristics are associated with the risk of reclassification from CFSPID to a CF diagnosis. METHODS Children with a positive CF NBS were recruited from two sites in California. Retrospective, longitudinal, and cross-sectional data were collected. A subset of subjects had nasal epithelial cells collected for CF transmembrane conductance regulator (CFTR) functional assessment. Multivariate logistic regression was used to assess the risk of reclassification. RESULTS A total of 112 children completed the study (CF = 53, CFSPID = 59). Phenotypic characteristics between groups showed differences in pancreatic insufficiency prevalence, immunoreactive trypsinogen (IRT) levels, and Pseudomonas aeruginosa (PSA) colonization. Spirometry measures were not different between groups. Nasal epithelial cells from 10 subjects showed 7%-30% of wild-type (WT)-CFTR (wtCFTR) function in those who reclassified and 27%-67% of wtCFTR function in those who retained the CFSPID designation. Modeling revealed that increasing sweat chloride concentration (sw[Cl- ]) and PSA colonization were independent risk factors for reclassification to CF. CONCLUSION Increasing sw[Cl- ] and a history of PSA colonization are associated with the risk of reclassification from CFSPID to CF in a population with high IRT and two CFTR variants. A close follow-up to monitor phenotypic changes remains critical in this population. The role of CFTR functional assays in this population requires further exploration.
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Affiliation(s)
- Danieli B Salinas
- Department of Pediatrics, Division of Pediatric Pulmonology, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Daniella K Ginsburg
- Department of Pediatrics, Division of Pediatric Pulmonology, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Choo Phei Wee
- Department of Population and Public Health Sciences, Keck School of Medicine, Southern California Clinical and Translational Science Institute (SC-CTSI), University of Southern California, Los Angeles, California, USA
| | - Muhammed M Saeed
- Division of Pediatric Pulmonology, Kaiser Permanente Los Angles Medical Center, Los Angeles, California, USA
| | - John J Brewington
- Department of Pediatrics, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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Sermet-Gaudelus I, Girodon E, Vermeulen F, Solomon G, Melotti P, Graeber S, Bronsveld I, Rowe S, Wilschanski M, Tümmler B, Cutting G, Gonska T. ECFS standards of care on CFTR-related disorders: Diagnostic criteria of CFTR dysfunction. J Cyst Fibros 2022; 21:922-936. [DOI: 10.1016/j.jcf.2022.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 09/06/2022] [Accepted: 09/14/2022] [Indexed: 11/06/2022]
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Impact of Pancreatitis-Associated Protein on Newborn Screening Outcomes and Detection of CFTR-Related Metabolic Syndrome (CRMS)/Cystic Fibrosis Screen Positive, Inconclusive Diagnosis (CFSPID): A Monocentric Prospective Pilot Experience. Int J Neonatal Screen 2022; 8:ijns8030046. [PMID: 35997436 PMCID: PMC9397086 DOI: 10.3390/ijns8030046] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/14/2022] [Accepted: 07/29/2022] [Indexed: 01/14/2023] Open
Abstract
Pancreatitis-Associated Protein (PAP)-based Cystic Fibrosis (CF) newborn bloodspot screening (NBS) protocols detect less CFTR-Related Metabolic Syndrome (CRMS)/CF Screen Positive, Inconclusive Diagnosis (CFSPID). We prospectively evaluated the impact of PAP as the second step of the CF NBS protocol, before the CFTR genetic analysis, on NBS outcomes and CRMS/CFSPID detection in the Tuscany region, Italy. In parallel to the usual protocol (IRT/DNA, protocol 1), PAP was analyzed in IRT-positive infants (IRT/PAP/DNA, protocol 2) from 1 June 2020 until 31 May 2022. We defined an infant as NBS positive if PAP was >1.8 μg/L for IRT value 99th percentile-100 μg/L or >0.6 μg/L for IRT value >100 μg/L. To increase the positive predictive value (PPV) of protocol 2, we retrospectively lowered the upper IRT range value from 100 to 90 μg/L (modified protocol 2). We identified 8 CF and 13 CRMS/CFSPID with protocol 1, 5 CF and 5 CRMS/CFSPID with protocol 2 and 8 CF and 5 CRMS/CFSPID with modified protocol 2. With the PAP-based protocols, we observed a reduction of sweat tests, healthy carrier detection and a significant increase in PPV to 15.38%. Further data are needed in order to evaluate the outcomes of CRMS/CFSPID after a long follow-up.
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11
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Determination of Cystic Fibrosis Mutation Frequency in Preterm and Term Neonates with Respiratory Tract Problems. Balkan J Med Genet 2022; 24:25-31. [PMID: 36249513 PMCID: PMC9524182 DOI: 10.2478/bjmg-2021-0023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Cystic fibrosis (CF) is an autosomal recessive disease. The genetic transition occurs with CF transmembrane conductance regulator (CFTR) gene mutation. We aimed to determine the frequency of CF mutations and also new mutations in the CFTR gene in neonates with respiratory distress. Newborn babies hospitalized due to respiratory distress were included in the patient group. The control group consisted of infants who had no respiratory distress. The CFTR genes of both groups were analyzed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods. A total of 40 patients (20 in the patient group and 20 in the control group) were evaluated. The CFTR gene analysis was normal in 16 neonates in the patient group, whereas in others: A46D (c.137C>A) (n = 1), D1312G (c.3935A>G) (n = 1), R117H (c.350G>A) (n = 1), S1426P (c.4276T>C) (n = 1) heterozygotes were detected; CFTR gene analysis was normal at 14 neonates in the control group, whereas in others: E1228G (c.3683A>G) (n = 1), E217G (c.650A>G) (n = 1), E632TfsX9 (c1894_1895delAG) (n = 1), I807M (c.2421 A>G) (n = 2), S573F (c.1718C>T) (n = 1) heterozygotes were detected. There was no significant difference in the patient and control groups’ CFTR gene analysis (p = 0.340). This study demonstrates the importance of CFTR gene analysis in asymptomatic newborn infants for follow-up and early diagnosis of CFTR-related disorders. In this study, a c.1894_1895delAG (E632TfsX9) heterozygous mutation detected in the CFTR gene in an asymptomatic newborn infant, was first encountered in the literature.
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12
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Hatton A, Bergougnoux A, Zybert K, Chevalier B, Mesbahi M, Altéri JP, Walicka-Serzysko K, Postek M, Taulan-Cadars M, Edelman A, Hinzpeter A, Claustres M, Girodon E, Raynal C, Sermet-Gaudelus I, Sands D. Reclassifying inconclusive diagnosis after newborn screening for cystic fibrosis. Moving forward. J Cyst Fibros 2021; 21:448-455. [PMID: 34949556 DOI: 10.1016/j.jcf.2021.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 10/19/2022]
Abstract
BACKGROUND Newborn screening for Cystic Fibrosis (CF) is associated with situations where the diagnosis of CF or CFTR related disorders (CFTR-RD) cannot be clearly ruled out. MATERIALS/PATIENTS AND METHODS We report a case series of 23 children with unconclusive diagnosis after newborn screening for CF and a mean follow-up of 7.7 years (4-13). Comprehensive investigations including whole CFTR gene sequencing, in vivo intestinal current measurement (ICM), nasal potential difference (NPD), and in vitro functional studies of variants of unknown significance, helped to reclassify the patients. RESULTS Extensive genetic testing identified, in trans with a CF causing mutation, variants with varying clinical consequences and 3 variants of unknown significance (VUS). Eighteen deep intronic variants were identified by deep resequencing of the whole CFTR gene in 13 patients and were finally considered as non-pathogenic. All patients had normal CFTR dependent chloride transport in ICM. NPD differentiated 3 different profiles: CF-like tracings qualifying the patients as CF, such as F508del/D1152H patients; normal responses, suggesting an extremely low likelihood of developing a CFTR-RD such as F508del/TG11T5 patients; partial CFTR dysfunction above 20% of the normal, highlighting a remaining risk of developing CFTR-RD such as F508del/F1052V patients. The 3 VUS were reclassified as variant with defective maturation (D537N), defective expression (T582I) or with no clinical consequence (M952T). CONCLUSION This study demonstrates the usefulness of combining genetic and functional investigations to assess the possibility of evolving to CF or CFTR-RD in babies with inconclusive diagnosis at neonatal screening.
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Affiliation(s)
- Aurelie Hatton
- INSERM U1151, Institut Necker Enfants Malades, Université de Paris, 149 rue de Sévres, Paris 75015, France; Université de Paris, Paris, France
| | - Anne Bergougnoux
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, Montpellier, France; CHU de Montpellier, Laboratoire de Génétique Moléculaire, Montpellier, France
| | - Katarzyna Zybert
- Cystic Fibrosis Department, Institute of Mother and Child, Warsaw, Poland
| | - Benoit Chevalier
- INSERM U1151, Institut Necker Enfants Malades, Université de Paris, 149 rue de Sévres, Paris 75015, France; Université de Paris, Paris, France
| | - Myriam Mesbahi
- INSERM U1151, Institut Necker Enfants Malades, Université de Paris, 149 rue de Sévres, Paris 75015, France; Université de Paris, Paris, France
| | - Jean Pierre Altéri
- CHU de Montpellier, Laboratoire de Génétique Moléculaire, Montpellier, France
| | | | - Magdalena Postek
- Cystic Fibrosis Department, Institute of Mother and Child, Warsaw, Poland
| | - Magali Taulan-Cadars
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, Montpellier, France; Université de Montpellier, Montpellier, France
| | - Aleksander Edelman
- INSERM U1151, Institut Necker Enfants Malades, Université de Paris, 149 rue de Sévres, Paris 75015, France; Université de Paris, Paris, France
| | - Alexandre Hinzpeter
- INSERM U1151, Institut Necker Enfants Malades, Université de Paris, 149 rue de Sévres, Paris 75015, France; Université de Paris, Paris, France
| | | | - Emmanuelle Girodon
- INSERM U1151, Institut Necker Enfants Malades, Université de Paris, 149 rue de Sévres, Paris 75015, France; Laboratoire de Génétique et Biologie Moléculaires, Hôpital Cochin, APHP Centre, Université de Paris, Paris, France
| | - Caroline Raynal
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, Montpellier, France; CHU de Montpellier, Laboratoire de Génétique Moléculaire, Montpellier, France
| | - Isabelle Sermet-Gaudelus
- INSERM U1151, Institut Necker Enfants Malades, Université de Paris, 149 rue de Sévres, Paris 75015, France; Université de Paris, Paris, France; Centre de Référence Maladies Rares, Mucoviscidose et maladies apparentées, Hôpital Necker Enfants Malades, Paris, France; European Reference Network-Lung, France.
| | - Dorota Sands
- Cystic Fibrosis Department, Institute of Mother and Child, Warsaw, Poland
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13
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Gonska T, Keenan K, Au J, Dupuis A, Chilvers MA, Burgess C, Bjornson C, Fairservice L, Brusky J, Kherani T, Jober A, Kosteniuk L, Price A, Itterman J, Morgan L, Mateos-Corral D, Hughes D, Donnelly C, Smith MJ, Iqbal S, Arpin J, Reisman J, Hammel J, van Wylick R, Derynck M, Henderson N, Solomon M, Ratjen F. Outcomes of Cystic Fibrosis Screening-Positive Infants With Inconclusive Diagnosis at School Age. Pediatrics 2021; 148:183433. [PMID: 34814176 DOI: 10.1542/peds.2021-051740] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/24/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Cystic fibrosis (CF) screen-positive infants with an inconclusive diagnosis (CFSPID) are infants in whom sweat testing and genetic analysis does not resolve a CF diagnosis. Lack of knowledge about the health outcome of these children who require clinical follow-up challenges effective consultation. Early predictive biomarkers to delineate the CF risk would allow a more targeted approach to these children. METHODS Prospective, longitudinal, multicenter, Canada-wide cohort study of CF positive-screened newborns with 1 to 2 cystic fibrosis transmembrane conductance regulator gene variants, of which at least 1 is not known to be CF-causing and/or a sweat chloride between 30 and 59 mmol/L. These were monitored for conversion to a CF diagnosis, pulmonary, and nutritional outcomes. RESULTS The mean observation period was 7.7 (95% confidence interval 7.1 to 8.4) years. A CF diagnosis was established for 24 of the 115 children with CFSPID (21%) either because of reinterpretation of the cystic fibrosis transmembrane conductance regulator genotype or because of increase in sweat chloride concentration ≥60 mmol/L. An initial sweat chloride of ≥40 mmol/l predicted conversion to CF on the basis of sweat testing. The 91 remaining children with CFSPID were pancreatic sufficient and showed normal growth until school age. Pulmonary function as well as lung clearance index in a subgroup of children with CFSPID were similar to that of healthy controls. CONCLUSIONS Children with CFSPID have good nutritional and pulmonary outcomes at school age, but rates of reclassifying the diagnosis are high. The initial sweat chloride test can be used as a biomarker to predict the risk for CF in CFSPID.
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Affiliation(s)
- Tanja Gonska
- Divisions of Gastroenterology, Hepatology.,Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Katherine Keenan
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jacky Au
- Respiratory Medicine, Department of Pediatrics
| | - Annie Dupuis
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Mark A Chilvers
- Division of Respiratory Medicine, Department of Pediatrics, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Caroline Burgess
- Division of Respiratory Medicine, Department of Pediatrics, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Candice Bjornson
- Section of Respiratory Medicine, Department of Pediatrics, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Lori Fairservice
- Section of Respiratory Medicine, Department of Pediatrics, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Janna Brusky
- Department of Pediatric, Jim Pattison Children's Hospital, Saskatoon, Saskatchewan, Canada
| | - Tamizan Kherani
- Division of Respiratory Medicine, Department of Pediatrics, Stollery Children's Hospital, Edmonton, Alberta, Canada
| | - Amanda Jober
- Division of Respiratory Medicine, Department of Pediatrics, Stollery Children's Hospital, Edmonton, Alberta, Canada
| | - Lorna Kosteniuk
- Department of Pediatric, Jim Pattison Children's Hospital, Saskatoon, Saskatchewan, Canada
| | - April Price
- Division of Respiratory Medicine, Department of Pediatrics, London Health Sciences Centre, London, Ontario, Canada
| | - Jennifer Itterman
- Division of Respiratory Medicine, Department of Pediatrics, London Health Sciences Centre, London, Ontario, Canada
| | - Lenna Morgan
- Department of Pediatrics, Windsor Regional Hospital, Windsor, Ontario, Canada
| | - Dimas Mateos-Corral
- Division of Respiratory Medicine, Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Daniel Hughes
- Division of Respiratory Medicine, Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Christine Donnelly
- Division of Respiratory Medicine, Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mary Jane Smith
- Department of Paediatrics, Memorial University of Newfoundland, St John's, Newfoundland and Labrador, Canada
| | - Shaikh Iqbal
- Department of Pediatrics, Children's Hospital of Winnipeg, Winnipeg, Manitoba, Canada
| | - Jocelyn Arpin
- Department of Pediatrics, Children's Hospital of Winnipeg, Winnipeg, Manitoba, Canada
| | - Joe Reisman
- Division of Respiratory Medicine, Department of Pediatrics, Children Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Joanne Hammel
- Division of Respiratory Medicine, Department of Pediatrics, Children Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | | | - Michael Derynck
- Department of Pediatrics, Queen's University, Kingston, Ontario, Canada
| | - Natalie Henderson
- Department of Pediatrics, Queen's University, Kingston, Ontario, Canada
| | | | - Felix Ratjen
- Respiratory Medicine, Department of Pediatrics.,Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
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Mikó Á, Kaposi A, Schnabel K, Seidl D, Tory K. Identification of incompletely penetrant variants and interallelic interactions in autosomal recessive disorders by a population-genetic approach. Hum Mutat 2021; 42:1473-1487. [PMID: 34405919 DOI: 10.1002/humu.24273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/30/2021] [Accepted: 08/15/2021] [Indexed: 01/11/2023]
Abstract
We aimed to identify incompletely penetrant (IP) variants and interallelic interactions in autosomal recessive disorders by a population-genetic approach. Genotype and clinical data were collected from 9038 patients of European origin with ASL, ATP7B, CAPN3, CFTR, CTNS, DHCR7, GAA, GALNS, GALT, IDUA, MUT, NPHS1, NPHS2, PAH, PKHD1, PMM2, or SLC26A4-related disorders. We calculated the relative allele frequency of each pathogenic variant (n = 1936) to the loss-of-function (LOF) variants of the corresponding gene in the patient ( A C p t V / A C p t L O F ) and the general population ( AC gnomAD V / AC gnomAD LOF ) and estimated the penetrance of each variant by calculating their ratio: ( A C p t V / A C p t L O F ) ( A C g n o m A D V / A C g n o m A D L O F ) (V/LOF ratio). We classified all variants as null or hypomorphic based on the associated clinical phenotype. We found 25 variants, 29% of the frequent 85 variants, to be underrepresented in the patient population (V/LOF ratio <30% with p < 7.22 × 10-5 ), including 22 novel ones in the ASL, CAPN3, CFTR, GAA, GALNS, PAH, and PKHD1 genes. In contrast to the completely penetrant variants (CP), the majority of the IP variants were hypomorphic (IP: 16/18, 88%; CP: 177/933, 19.0%; p = 5.12 × 10-10 ). Among them, only the NPHS2 R229Q variant was subject to interallelic interactions. The proposed algorithm identifies frequent IP variants and estimates their penetrance and interallelic interactions in large patient cohorts.
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Affiliation(s)
- Ágnes Mikó
- MTA-SE Lendület Nephrogenetic Laboratory, Hungarian Academy of Sciences, Budapest, Hungary.,1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Ambrus Kaposi
- MTA-SE Lendület Nephrogenetic Laboratory, Hungarian Academy of Sciences, Budapest, Hungary.,Department of Programming Languages and Compilers, Faculty of Informatics, Eötvös Loránd University, Budapest, Hungary
| | - Karolina Schnabel
- MTA-SE Lendület Nephrogenetic Laboratory, Hungarian Academy of Sciences, Budapest, Hungary.,1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Dániel Seidl
- MTA-SE Lendület Nephrogenetic Laboratory, Hungarian Academy of Sciences, Budapest, Hungary.,1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Kálmán Tory
- MTA-SE Lendület Nephrogenetic Laboratory, Hungarian Academy of Sciences, Budapest, Hungary.,1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
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15
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Nykamp K, Truty R, Riethmaier D, Wilkinson J, Bristow SL, Aguilar S, Neitzel D, Faulkner N, Aradhya S. Elucidating clinical phenotypic variability associated with the polyT tract and TG repeats in CFTR. Hum Mutat 2021; 42:1165-1172. [PMID: 34196078 PMCID: PMC9292755 DOI: 10.1002/humu.24250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 06/22/2021] [Accepted: 06/24/2021] [Indexed: 02/05/2023]
Abstract
Biallelic pathogenic variants in CFTR manifest as cystic fibrosis (CF) or other CFTR-related disorders (CFTR-RDs). The 5T allele, causing alternative splicing and reduced protein activity, is modulated by the adjacent TG repeat element, though previous data have been limited to small, selective cohorts. Here, the risk and spectrum of phenotypes associated with the CFTR TG-T5 haplotype variants (TG11T5, TG12T5, and TG13T5) in the absence of the p.Arg117His variant are evaluated. Individuals who received physician-ordered next-generation sequencing of CFTR were included. TG[11-13]T5 variant frequencies (biallelic or with another CF-causing variant [CFvar]) were calculated. Clinical information reported by the ordering provider or the individual was examined. Among 548,300 individuals, the T5 minor allele frequency (MAF) was 4.2% (TG repeat distribution: TG11 = 68.1%, TG12 = 29.5%, TG13 = 2.4%). When present with a CFvar, each TG[11-13]T5 variant was significantly enriched in individuals with a high suspicion of CF or CFTR-RD (personal/family history of CF/CFTR-RD) compared to those with a low suspicion for CF or CFTR-RD (hereditary cancer screening, CFTR not requisitioned). Compared to CFvar/CFvar individuals, those with TG[11-13]T5/CFvar generally had single-organ involvement, milder symptoms, variable expressivity, and reduced penetrance. These data improve our understanding of disease risks associated with TG[11-13]T5 variants and have important implications for reproductive genetic counseling.
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16
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Munck A, Cheillan D, Audrezet MP, Guenet D, Huet F. [Newborn screening for cystic fibrosis in France]. Med Sci (Paris) 2021; 37:491-499. [PMID: 34003095 DOI: 10.1051/medsci/2021051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Neonatal screening for cystic fibrosis has optimised the prognosis for patients allowing very early multidisciplinary care. Over the past 20 years, screening programmes have undergone major international expansion. The performances of the French neonatal cystic fibrosis screening programme, established in 2002, has met European guideline standards, with positive predictive value of 0.31 (against a minimum of 0.30) and sensitivity value of 0.95 (against a minimum of 0.95). It is also important to highlight the very high percentage of sweat tests performed (95.5%), of mutations identified (96.6%), the 9:1 ratio of cystic fibrosis cases to cases of inconclusive diagnosis achieved and the effectiveness of the strategy implemented for the detection of false negative cases. A new organisation for cystic fibrosis neonatal screening has now been established in France. It is vital that effectiveness is maintained throughout the process, from newborn maternity care to diagnosis in cystic fibrosis care centres, and that further knowledge is gained through exhaustive data collection and validation.
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Affiliation(s)
- Anne Munck
- Société française de dépistage néonatal, Paris, France - Centre de ressource et de compétence de la mucoviscidose, Hopital Necker-Enfants malades, AP-HP, 149 rue de Sèvres, 75015 Paris, France
| | - David Cheillan
- Société française de dépistage néonatal, Paris, France - Service biochimie et biologie moléculaire Grand Est, Centre de biologie et de pathologie Est, Groupement hospitalier Est-Hospices civils de Lyon, 59 boulevard Pinel, 69677 Bron Cedex, France - Commission de biologie - Centre national de coordination du dépistage néonatal, Paris, France
| | - Marie-Pierre Audrezet
- Commission de biologie - Centre national de coordination du dépistage néonatal, Paris, France - Service de génétique médicale et biologie de la reproduction, CHRU de Brest, Inserm UMR1078 - Génétique, génomique et biotechnologies, F-29200, Brest, France
| | - David Guenet
- Laboratoire de biologie médicale, Centre régional de dépistage néonatal, Service de biochimie, CHU de Caen Normandie, Caen, France
| | - Frédéric Huet
- Société française de dépistage néonatal, Paris, France - Service de pédiatrie 1 et génétique médicale, 14 rue Paul Gaffarel, BP 77908, 21079 Dijon Cedex, France
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17
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Bergougnoux A, Ea V, Paris F, Kalfa N. Reply to Zhongzhong Chen, Hua Xie, and Fang Chen's Letter to the Editor re: Vuthy Ea, Anne Bergougnoux, Pascal Philibert, et al. How Far Should We Explore Hypospadias? Next-generation Sequencing Applied to a Large Cohort of Hypospadiac Patients. Eur Urol 2021;79:507-15. Eur Urol 2021; 80:e12-e13. [PMID: 33849729 DOI: 10.1016/j.eururo.2021.03.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 03/29/2021] [Indexed: 11/17/2022]
Affiliation(s)
- Anne Bergougnoux
- Centre de Référence Maladies Rares DEVGEN Constitutif Sud, CHU de Montpellier, Montpellier, France; Laboratoire de Génétique Moléculaire, IURC, CHU de Montpellier, Montpellier, France; PhyMedExp, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Vuthy Ea
- Centre de Référence Maladies Rares DEVGEN Constitutif Sud, CHU de Montpellier, Montpellier, France; Laboratoire de Génétique Moléculaire, IURC, CHU de Montpellier, Montpellier, France
| | - Françoise Paris
- Centre de Référence Maladies Rares DEVGEN Constitutif Sud, CHU de Montpellier, Montpellier, France; Laboratoire de Génétique Moléculaire, IURC, CHU de Montpellier, Montpellier, France; Unité d'Endocrinologie Pédiatrique, Service de Pédiatrie, Hôpital Arnaud de Villeneuve, CHU de Montpellier, Montpellier, France; Développement Embryonnaire Précoce, Fertilité et Environnement, INSERM, Université de Montpellier, Montpellier, France
| | - Nicolas Kalfa
- Centre de Référence Maladies Rares DEVGEN Constitutif Sud, CHU de Montpellier, Montpellier, France; Chirurgie et Urologie Pédiatrique, Hôpital Lapeyronie, CHU de Montpellier, Université de Montpellier, Montpellier, France; Institut Desbrest d'Epidémiologie et de Santé PubliqueUMR INSERM - Université de Montpellier, France.
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18
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Doull I, Course CW, Hanks RE, Southern KW, Forton JT, Thia LP, Moat SJ. Cystic fibrosis newborn screening: the importance of bloodspot sample quality. Arch Dis Child 2021; 106:253-257. [PMID: 32859613 DOI: 10.1136/archdischild-2020-318999] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Wales has an immunoreactive trypsin (IRT)-DNA cystic fibrosis (CF) newborn screening (NBS) programme. Most CF NBS false negative cases are due to an IRT concentration below the screening threshold. The accuracy of IRT results is dependent on the quality of the dried bloodspot (DBS) sample. The aim of this study was to determine the cause of false negative cases in CF NBS and their relationship to DBS quality. DESIGN Longitudinal birth cohort. SETTING Wales 1996-2016. PATIENTS Children with CF. INTERVENTIONS Identification of all CF patients with triangulation of multiple data sources to detect false negative cases. MAIN OUTCOME MEASURES False negative cases. RESULTS Over 20 years, 673 952 infants were screened and 239 were diagnosed with CF (incidence 1:2819). The sensitivity of the programme was 0.958, and positive predictive value was 0.476. Eighteen potential false negatives were identified, of whom eight were excluded: four screened outside Wales, two had complex comorbidities, no identified cystic fibrosis transmembrane conductance regulator (CFTR) variants on extended analysis and thus not considered to have CF and two were diagnosed after their 16th birthday. Of the 10 false negatives, 9 had a low DBS IRT and at least one common CFTR variant and thus should have received a sweat test under the programme. DBS cards were available for inspection for five of the nine false negative cases-all were classified as small/insufficient or poor quality. CONCLUSIONS The majority of false negatives had a low bloodspot IRT, and this was associated with poor quality DBS. The optimal means to improve the sensitivity of our CF NBS programme would be to improve DBS sample quality.
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Affiliation(s)
- Iolo Doull
- Department of Paediatric Respiratory Medicine and Paediatric Cystic Fibrosis Centre, Children's Hospital for Wales, Cardiff, UK
| | - Christopher William Course
- Department of Paediatric Respiratory Medicine and Paediatric Cystic Fibrosis Centre, Children's Hospital for Wales, Cardiff, UK
| | - Ruth E Hanks
- Department of Paediatric Respiratory Medicine and Paediatric Cystic Fibrosis Centre, Children's Hospital for Wales, Cardiff, UK
| | - Kevin W Southern
- Department of Women's and Children's Health, University of Liverpool, Liverpool, UK
| | - Julian T Forton
- Department of Paediatric Respiratory Medicine and Paediatric Cystic Fibrosis Centre, Children's Hospital for Wales, Cardiff, UK
| | - Lena P Thia
- Department of Paediatric Respiratory Medicine and Paediatric Cystic Fibrosis Centre, Children's Hospital for Wales, Cardiff, UK
| | - Stuart J Moat
- Department of Medical Biochemistry, Immunology & Toxicology, University Hospital of Wales, Cardiff, UK.,School of Medicine, Cardiff University, Cardiff, UK
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19
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Kiseleva A, Klimushina M, Sotnikova E, Skirko O, Divashuk M, Kurilova O, Ershova A, Khlebus E, Zharikova A, Efimova I, Pokrovskaya M, Slominsky PA, Shalnova S, Meshkov A, Drapkina O. Cystic Fibrosis Polymorphic Variants in a Russian Population. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2021; 13:679-686. [PMID: 33623413 PMCID: PMC7894124 DOI: 10.2147/pgpm.s278806] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/28/2020] [Indexed: 11/23/2022]
Abstract
Purpose Cystic fibrosis (CF) is one of the most common monogenic diseases with an autosomal recessive inheritance. Carrier screening leads to a reduction in the number of children born with CF disease. The aim of this study was to develop the custom panel for the diagnosis of heterozygous carriage of polymorphic variants in the CFTR gene and to establish their allelic frequencies (AF) in one of the Russian regions where ethnic Russians predominate. Patients and Methods The diagnostic panel was designed on the basis of data from the register of CF patients in Russia for 2017 and validated on 22 blood samples of patients with previously genetically established CF. The study participants (n=642) for CF variants estimation were randomly selected from the population-based cohort study ESSE-Vologda. Genotypes were determined by real-time PCR on the QuantStudio 12K Flex Real-Time PCR System. Data processing was performed using the TaqMan Genotyper Software. Results The proposed diagnostic panel allowed simultaneous analysis of 60 variants of the CFTR gene. A total of 23 carriers of the following variants were identified among 642 participants: F508del (rs113993960) with a frequency of 2.02%, L138ins (rs397508686) and 394delTT (rs121908769) – 0.47%, CFTRdele2.3 (c.54–5940_273+10250del21080; p.S18Rfs*16) – 0.31%, R117H (rs78655421), and G542X (rs113993959) – 0.16%. The frequency of heterozygotes in the Russian population was 3.58% or 1:28 (CI95%: 2.28–5.33% by Clopper–Pearson exact method). Conclusion High frequency of heterozygous CFTR variants carriers and availability of highly productive diagnostic panel for detection of CFTR variants suggest the prospect of carrier screening for some common CF variants among Russian population.
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Affiliation(s)
- Anna Kiseleva
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
| | - Marina Klimushina
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
| | - Evgeniia Sotnikova
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
| | - Olga Skirko
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
| | - Mikhail Divashuk
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia.,Kurchatov Genomics Center-ARRIAB, All-Russia Research Institute of Agricultural Biotechnology, Moscow 127550, Russia
| | - Olga Kurilova
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
| | - Alexandra Ershova
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
| | - Eleonora Khlebus
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
| | - Anastasia Zharikova
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia.,Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119991, Russia.,Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow 127051, Russia
| | - Irina Efimova
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
| | - Maria Pokrovskaya
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
| | - Petr A Slominsky
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow 123182, Russia
| | - Svetlana Shalnova
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
| | - Alexey Meshkov
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
| | - Oxana Drapkina
- Federal State Institution «National Medical Research Center for Therapy and Preventive Medicine» of the Ministry of Healthcare of the Russian Federation, Moscow, 101000, Russia
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20
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Audrézet MP, Munck A. Newborn screening for CF in France: An exemplary national experience. Arch Pediatr 2020; 27 Suppl 1:eS35-eS40. [PMID: 32172935 DOI: 10.1016/s0929-693x(20)30049-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
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.
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Affiliation(s)
- M P Audrézet
- CHU Brest, Inserm, UMR 1078, F-29200, Brest, France.
| | - A Munck
- Société Française de Dépistage Néonatal, France; CRCM Hopital Necker Enfants Malades, Paris
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21
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Barben J, Castellani C, Munck A, Davies JC, de Winter-de Groot KM, Gartner S, Kashirskaya N, Linnane B, Mayell SJ, McColley S, Ooi CY, Proesmans M, Ren CL, Salinas D, Sands D, Sermet-Gaudelus I, Sommerburg O, Southern KW. Updated guidance on the management of children with cystic fibrosis transmembrane conductance regulator-related metabolic syndrome/cystic fibrosis screen positive, inconclusive diagnosis (CRMS/CFSPID). J Cyst Fibros 2020; 20:810-819. [PMID: 33257262 DOI: 10.1016/j.jcf.2020.11.006] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/30/2020] [Accepted: 11/07/2020] [Indexed: 02/06/2023]
Abstract
Over the past two decades there has been considerable progress with the evaluation and management of infants with an inconclusive diagnosis following Newborn Screening (NBS) for cystic Fibrosis (CF). In addition, we have an increasing amount of evidence on which to base guidance on the management of these infants and, importantly, we have a consistent designation being used across the globe of CRMS/CFSPID. There is still work to be undertaken and research questions to answer, but these infants now receive more consistent and appropriate care pathways than previously. It is clear that the majority of these infants remain healthy, do not convert to a diagnosis of CF in childhood, and advice on management should reflect this. However, it is also clear that some will convert to a CF diagnosis and monitoring of these infants should facilitate their early recognition. Those infants that do not convert to a CF diagnosis have some potential of developing a CFTR-RD later in life. At present, it is not possible to quantify this risk, but families need to be provided with clear information of what to look out for. This paper contains a number of changes from previous guidance in light of developing evidence, but the major change is the recommendation of a detailed assessment of the child with CRMS/CFSPID in the sixth year of age, including respiratory function assessment and imaging. With these data, the CF team can discuss future care arrangements with the family and come to a shared decision on the best way forward, which may include discharge to primary care with appropriate information. Information is key for these families, and we recommend consideration of a further appointment when the individual is a young adult to directly communicate the implications of the CRMS/CFSPID designation.
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Affiliation(s)
- Jürg Barben
- Paediatric Pulmonology & CF Centre, Children's Hospital of Eastern Switzerland, St. Gallen, Switzerland.
| | - Carlo Castellani
- Istituto Giannina Gaslini, IRCCS Istituto Giannina Gaslini, Genova, Italy
| | - Anne Munck
- CF referent physician for the French Society of Newborn Screening, Hopital Necker Enfants-Malades, AP-HP, CF centre, Université Paris Descartes, France
| | - Jane C Davies
- National Heart & Lung Institute, Imperial College London, UK; Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Karin M de Winter-de Groot
- Department of Paediatric Pulmonology & Allergology, Wilhelmina Children's Hospital/University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Silvia Gartner
- Pediatric Pulmonology and Cystic Fibrosis Unit, Hospital Universitari Vall d´Hebron, Barcelona, Spain
| | - Nataliya Kashirskaya
- Laboratory of genetic epidemiology, Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Barry Linnane
- Graduate Entry Medical School and Centre for Interventions in Infection, Inflammation & Immunity (4i), University of Limerick, Limerick, Ireland
| | - Sarah J Mayell
- Regional Paediatric CF Centre, Alder Hey Children's Hospital, Liverpool, UK
| | - Susanna McColley
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Stanley Manne Children's Research Institute, Ann and Robert H Lurie Children's Hospital of Chicago, USA
| | - Chee Y Ooi
- Discipline of Paediatrics, School of Women's and Children's Health, Faculty of Medicine, University of New South Wales, Australia; Department of Gastroenterology and Molecular and Integrative Cystic Fibrosis Research Centre, Sydney Children's Hospital, Randwick, NSW, Australia
| | - Marijke Proesmans
- Division of Woman and Child, Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Clement L Ren
- Department of Pediatrics, Indiana University School of Medicine, Division of Pediatric Pulmonology, Allergy and Sleep Medicine, Riley Hospital for Children, Indianapolis, USA
| | - Danieli Salinas
- Department of Pediatric Pulmonology, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, USA
| | - Dorota Sands
- Cystic Fibrosis Department, Institute of Mother and Child, Warsaw, Poland
| | - Isabelle Sermet-Gaudelus
- Institut Necker Enfants Malades/INSERM U1151, Service de Pneumologie et Allergologie Pédiatriques Centre de Référence Maladies Rares, Mucoviscidose et maladies de CFTR, Hôpital Necker Enfants Malades Paris. Université de Paris. ERN Lung, France
| | - Olaf Sommerburg
- Paediatric Pulmonology, Allergology & CF Centre, Department of Paediatrics III, and Translational Lung Research Center, German Lung Research Center, University Hospital Heidelberg, Germany
| | - Kevin W Southern
- Department of Women's and Children's Health, University of Liverpool, UK
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22
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Fitzgerald C, Linnane B, George S, Ni Chroinin M, Mullane D, Herzig M, Greally P, Elnazir B, Healy F, Mc Nally P, Javadpour S, Cox D, Fitzpatrick P. Neonatal screening programme for CF: Results from the Irish Comparative Outcomes Study (ICOS). Pediatr Pulmonol 2020; 55:2323-2329. [PMID: 32470170 DOI: 10.1002/ppul.24876] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/23/2020] [Accepted: 05/09/2020] [Indexed: 11/07/2022]
Abstract
The introduction of NBS in Ireland in July 2011, provided a unique opportunity to investigate clinical outcomes using a comparative historical cohort study. Clinical cohort: children clinically diagnosed with CF born 1 July 2008 to 30 June 2011, and NBS cohort: children diagnosed with CF through NBS born 1 July 2011 to 30 June 2016. Clinical data were collected from the CF Registry of Ireland, medical charts, and data on weight/height before diagnosis from public health nurses and family doctors. SPSS was used for analysis. A total of 232 patients were recruited (response 93%) (93 clinically diagnosed, 139 NBS-detected). Following exclusions of meconium ileus (MI) (40), diagnosis outside Ireland (4), and being designated as CFSPID (2), a total of 77 clinically diagnosed patients and 109 NBS detected children were included in analysis. Over half were homozygous for F508del mutation. Being clinically diagnosed was independently associated with hospitalization for infective exacerbation of CF < 36 months (OR, 2.80; 95%CI 1.24-6.29). Diagnosis to first acquisition of Pseudomonas aeruginosa was significantly longer in NBS than clinically detected; from birth there was no significant difference. Weight and length/height were significantly greater in NBS cohort at 6 and 12 months. We provide evidence of improved growth, reduced hospitalization for acute exacerbations, and delayed P. aeruginosa acquisition (from diagnosis) to age 3 for the NBS cohort. Screening practices likely account for the non-significant difference in P. aeruginosa acquisition from birth.
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Affiliation(s)
- Catherine Fitzgerald
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
| | - Barry Linnane
- Graduate Entry Medical School and Centre for Interventions in Infection, Inflammation & Immunity (4i), University of Limerick, Limerick, Ireland.,National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland
| | - Sherly George
- Department of Nursing, Royal College of Surgeons in Ireland, Dublin, Ireland
| | | | - David Mullane
- Department of Paediatrics, Galway University Hospital, Galway, Ireland
| | - Mary Herzig
- Department of Paediatrics, The National Children's Hospital, Dublin, Ireland
| | - Peter Greally
- Respiratory Department, The Children's University Hospital, Temple St, Dublin, Ireland
| | - Basil Elnazir
- Department of Respirology, Our Lady's Children's Hospital, Dublin, Ireland
| | - Fiona Healy
- Respiratory Department, The Children's University Hospital, Temple St, Dublin, Ireland
| | - Paul Mc Nally
- Department of Respirology, Our Lady's Children's Hospital, Dublin, Ireland.,Department of Paediatrics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Sheila Javadpour
- Department of Respirology, Our Lady's Children's Hospital, Dublin, Ireland
| | - Des Cox
- Department of Respirology, Our Lady's Children's Hospital, Dublin, Ireland
| | - Patricia Fitzpatrick
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
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23
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Laudus N, Audrézet MP, Girodon E, Morris MA, Radojkovic D, Raynal C, Seia M, Štambergová A, Torkler H, Yamamoto R, Dequeker EMC. Laboratory reporting on the clinical spectrum of CFTR p.Arg117His: Still room for improvement. J Cyst Fibros 2020; 19:969-974. [PMID: 32505523 DOI: 10.1016/j.jcf.2020.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 05/14/2020] [Accepted: 05/19/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND The clinical spectrum associated with cystic fibrosis transmembrane conductance regulator (CFTR) variant p.Arg117His is highly variable, ranging from full-blown cystic fibrosis (CF) in a small number of cases to CFTR-related disorders (CFTR-RDs) or no symptoms at all. Therefore, taking into account phenotype variability is essential for interpretation. External quality assessment (EQA) schemes can help laboratories to objectively assess the quality of genotyping and reporting by the laboratory. METHODS We performed a retrospective longitudinal data analysis on laboratory performance regarding the interpretation of p.Arg117His during CF EQA scheme participation. Completeness and accuracy of reporting on two mock clinical cases were each compared over time (case 1: 2005, 2007 and 2012; case 2: 2015 and 2018). These cases concerned subjects compound heterozygous for p.Phe508del and p.Arg117His in cis with 7T, but with different clinical backgrounds (family planning (case 1) versus diagnostic testing for a child (case 2)). Furthermore, we analyzed the influence of previous participations, annual test volume, accreditation status and laboratory setting on overall performance. RESULTS Overall performance improved over time, except during the 2007 CF EQA scheme. In addition, previous participations had a beneficial effect on laboratory performance. Accreditation status, annual test volume and laboratory setting did not significantly influence total interpretation scores. CONCLUSIONS In general, laboratories performed well on both cases, although reporting on the variable clinical spectrum of p.Arg117His in cis with 7T and on the disease liability of individual CFTR variants can still improve. Moreover, this study underlined the educational role of CF EQA schemes.
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Affiliation(s)
- Nele Laudus
- Biomedical Quality Assurance Research Unit, Department of Public Health and Primary Care, University of Leuven, Leuven, Belgium
| | | | - Emmanuelle Girodon
- Laboratoire de Génétique et Biologie Moléculaires, AP-HP.Centre-Université de Paris, Hôpital Cochin, Paris, France
| | | | - Dragica Radojkovic
- Laboratory for Molecular Biology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Caroline Raynal
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Montpellier, France
| | - Manuela Seia
- Laboratorio di Genetica Medica - Settore di Genetica Molecolare, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Alexandra Štambergová
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague, Czech Republic
| | - Heike Torkler
- MVZ Dr. Eberhard & Partner Dortmund, Dortmund, Germany
| | | | - Elisabeth M C Dequeker
- Biomedical Quality Assurance Research Unit, Department of Public Health and Primary Care, University of Leuven, Leuven, Belgium; Department of Medical Diagnostics, University Hospitals Leuven, Leuven, Belgium.
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24
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Bienvenu T, Lopez M, Girodon E. Molecular Diagnosis and Genetic Counseling of Cystic Fibrosis and Related Disorders: New Challenges. Genes (Basel) 2020; 11:E619. [PMID: 32512765 PMCID: PMC7349214 DOI: 10.3390/genes11060619] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 11/16/2022] Open
Abstract
Identification of the cystic fibrosis transmembrane conductance regulator (CFTR) gene and its numerous variants opened the way to fantastic breakthroughs in diagnosis, research and treatment of cystic fibrosis (CF). The current and future challenges of molecular diagnosis of CF and CFTR-related disorders and of genetic counseling are here reviewed. Technological advances have enabled to make a diagnosis of CF with a sensitivity of 99% by using next generation sequencing in a single step. The detection of heretofore unidentified variants and ethnic-specific variants remains challenging, especially for newborn screening (NBS), CF carrier testing and genotype-guided therapy. Among the criteria for assessing the impact of variants, population genetics data are insufficiently taken into account and the penetrance of CF associated with CFTR variants remains poorly known. The huge diversity of diagnostic and genetic counseling indications for CFTR studies makes assessment of variant disease-liability critical. This is especially discussed in the perspective of wide genome analyses for NBS and CF carrier screening in the general population, as future challenges.
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Affiliation(s)
| | | | - Emmanuelle Girodon
- Molecular Genetics Laboratory, Cochin Hospital, APHP.Centre–Université de Paris, 75014 Paris, France; (T.B.); (M.L.)
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25
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Turner H, Jackson L. Evidence for penetrance in patients without a family history of disease: a systematic review. Eur J Hum Genet 2020; 28:539-550. [PMID: 31937893 PMCID: PMC7170932 DOI: 10.1038/s41431-019-0556-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 10/08/2019] [Accepted: 11/26/2019] [Indexed: 01/21/2023] Open
Abstract
Family-based penetrance is frequently cited as a major challenge for translating penetrance estimates from familial populations to asymptomatic populations. A systematic review was performed to assess the literature evidencing penetrance estimates in patients without a family history of disease, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework. Initially 1592 papers were identified, which were filtered to a final nine, through application of inclusion and exclusion criteria. Fundamental differences in the identified papers prevented combination of papers using meta-analysis, so thematic analysis to produce a narrative synthesis was performed. Key themes included disease risk modifiers, evidence, study limitations and bias. A methodological appraisal too was used to assess quality of included studies. It is evident from the findings that the evidence base for penetrance estimates in individuals without a family history of disease is limited. Future work is needed to refine design of penetrance studies and the impact of incorrect estimates.
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Affiliation(s)
- Heather Turner
- University of Exeter Medical School, 4.07 RILD, Royal Devon & Exeter Hospital, Barrack Road, Exeter, EX2 5DW, UK
| | - Leigh Jackson
- University of Exeter Medical School, 4.07 RILD, Royal Devon & Exeter Hospital, Barrack Road, Exeter, EX2 5DW, UK.
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26
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Boussaroque A, Audrézet MP, Raynal C, Sermet-Gaudelus I, Bienvenu T, Férec C, Bergougnoux A, Lopez M, Scotet V, Munck A, Girodon E. Penetrance is a critical parameter for assessing the disease liability of CFTR variants. J Cyst Fibros 2020; 19:949-954. [PMID: 32327388 DOI: 10.1016/j.jcf.2020.03.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 03/23/2020] [Accepted: 03/26/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Major issues of newborn screening (NBS) for CF are the assessment of disease liability of variants and of the penetrance of clinical CF, notably in inconclusive diagnosis. The penetrance of CF is defined as the risk of a particular genotype to lead to a CF phenotype. METHODS We aimed to get insight into the penetrance of CF for fifteen CFTR variants: 5 frequent CF-causing and 10 classified as of varying clinical consequence (VCC) or associated with a CFTR-related disorder (CFTR-RD) in CFTR2 or CFTR-France databases. The penetrance was approached by: (1) comparison of variant allelic frequencies in CF patients (CFTR2) and in the general population; (2) estimation of the likelihood of a positive NBS test for the 14 compound heterozygous with F508del and the F508del homozygous genotypes, defined as the ratio of detected/expected number of neonates with a given genotype in the 2002-2017 period. RESULTS A full penetrance was observed for severe CF-causing variants. Five variants were more frequently found in the general population than in CF patients: TG11T5, TG12T5, TG13T5, L997F and R117H;T7. The likelihood of a positive NBS test was 0.03% for TG11T5, 0.3% for TG12T5, 1.9% for TG13T5, 0.6% for L997F, 11.7% for D1152H, and 17.8% for R117H;T7. Penetrance varied greatly for variants with discrepant classification between CFTR2 and CFTR-France: 5.1% for R117C, 12.3% for T338I, 43.5% for D110H and 52.6% for L206W. CONCLUSION These results illustrate the contribution of genetics population data to assess the disease liability of variants for diagnosis and genetic counselling purposes.
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Affiliation(s)
- A Boussaroque
- APHP.Centre-Université de Paris, Cochin Hospital, Molecular Genetics Laboratory, Paris, France
| | - M-P Audrézet
- Molecular Genetics Laboratory - CHRU Brest, Brest, France; Inserm UMR 1078, GGB, F-29200 Brest, France
| | - C Raynal
- Molecular Genetics Laboratory - CHU Montpellier, EA7402 Université de Montpellier, Montpellier, France
| | - I Sermet-Gaudelus
- APHP.Centre Université de Paris, Necker Enfants Malades Hospital, Cystic Fibrosis Center, Paris, France and INSERM U 1151, Paris, France
| | - T Bienvenu
- APHP.Centre-Université de Paris, Cochin Hospital, Molecular Genetics Laboratory, Paris, France
| | - C Férec
- Molecular Genetics Laboratory - CHRU Brest, Brest, France; Inserm UMR 1078, GGB, F-29200 Brest, France
| | - A Bergougnoux
- Molecular Genetics Laboratory - CHU Montpellier, EA7402 Université de Montpellier, Montpellier, France
| | - M Lopez
- APHP.Centre-Université de Paris, Cochin Hospital, Molecular Genetics Laboratory, Paris, France
| | - V Scotet
- Inserm UMR 1078, GGB, F-29200 Brest, France
| | - A Munck
- APHP.Centre Université de Paris, Necker Enfants Malades Hospital, Cystic Fibrosis Center, Paris, France and INSERM U 1151, Paris, France; Société francaise de dépistage néonatal
| | - E Girodon
- APHP.Centre-Université de Paris, Cochin Hospital, Molecular Genetics Laboratory, Paris, France.
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27
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Munck A, Bourmaud A, Bellon G, Picq P, Farrell PM. Phenotype of children with inconclusive cystic fibrosis diagnosis after newborn screening. Pediatr Pulmonol 2020; 55:918-928. [PMID: 31916691 DOI: 10.1002/ppul.24634] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 12/27/2019] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To characterize the phenotypic expression of children with conductance regulator-related metabolic syndrome (CRMS)/cystic fibrosis screen positive inconclusive diagnosis (CFSPID) designation after positive newborn screening, reassign labeling if applicable and better define these children's prognosis. METHODS A multicenter cohort with CRMS/CFSPID designation was matched with cystic fibrosis (CF)-diagnosed cohort. Cohorts were prospectively compared on baseline characteristics, cumulative data and when they reached 6 to 7 years at endpoint assessment. RESULTS Compared to infants with CF (n = 63), the CRMS/CFSPID cohort (n = 63) had initially lower immunoreactive trypsinogen (IRT) and sweat chloride (SC) values, delayed visits, less symptoms, and better nutritional status; during follow-up, they had fewer hospitalizations, Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus identification, CF comorbidities, and treatment burden. At endpoint assessment, they presented a milder pulmonary phenotype on Brody computed tomography scores (0.0[0.0; 2.0] vs 13[2.0; 31.0]; P < .0001, respectively), Wisconsin and Brasfield chest radiograph scores, pulmonary function tests, and improved nutritional status. Among the inconclusive CF diagnosis cohort, 28 cases (44%) converted to CF diagnosis based on genotype (44%), SC (28%) or both (28%); yet, comparing those with or without final CF diagnosis, we found no differences, possibly related to their young age and mild degree of lung disease. In the total cohort, we found significant associations between Brody scores and IRT, SC values, genotype, Wisconsin and Brasfield score and spirometry. CONCLUSIONS The matched CRMS/CFSPID and CF cohorts showed differences in outcomes. By a mean age of 7.6 years, a high proportion of the CRMS/CFSPID cohort converted to CF. Our results highlight that monitoring at CF clinics until at least 6 years is needed as well as further studies.
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Affiliation(s)
- Anne Munck
- Service des maladies digestives et respiratoires de l'enfant, CRCM, Hôpital Robert Debré, AP-HP, Université Paris Diderot, Paris, France
| | - Aurélie Bourmaud
- Université Paris Diderot, Sorbonne Paris Cité, AP-HP, Inserm, Hôpital Robert Debré, Unité d'Epidémiologie Clinique, Paris, France
| | - Gabriel Bellon
- Service de pédiatrie, CRCM, Hospices Civils de Lyon, Université de Lyon, Villeurbanne, France
| | - Paul Picq
- Université Paris Diderot, Sorbonne Paris Cité, AP-HP, Inserm, Hôpital Robert Debré, Unité d'Epidémiologie Clinique, Paris, France
| | - Philip M Farrell
- Departments of Pediatrics and Population Health Sciences, UW School of Medicine and Public Health, Madison, Wisconsin
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28
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Januska MN, Marx L, Walker PA, Berdella MN, Langfelder-Schwind E. The CFTR variant profile of Hispanic patients with cystic fibrosis: Impact on access to effective screening, diagnosis, and personalized medicine. J Genet Couns 2020; 29:607-615. [PMID: 32227567 DOI: 10.1002/jgc4.1271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 11/11/2022]
Abstract
Hispanic patients comprise an appreciable and increasing proportion of patients with cystic fibrosis (CF) in the United States (US). Hispanic patients with CF are known to have increased morbidity and mortality compared to non-Hispanic white patients with CF, and ongoing investigations are underway to identify contributing factors amenable to intervention in order to address the disparate health outcomes. One contributing factor is the different CF transmembrane conductance regulator (CFTR) variant profile observed in Hispanic patients with CF. The most common CFTR variant, p.Phe508del (legacy name F508del), is proportionally underrepresented in Hispanic patients with CF. This difference has implications for prenatal screening, newborn screening (NBS), and CFTR variant-specific therapeutic options. In particular, the recent approval of a highly effective CFTR modulator for patients carrying at least one copy of F508del, elexacaftor/tezacaftor/ivacaftor triple combination therapy, underscores the potential for unequal access to personalized treatment for Hispanic patients with CF. We report the CFTR variant profiles of Hispanic patients with CF and non-CF Hispanic infants with a false-positive New York State CF NBS at a single center in New York City over a 5-year study period, as an opportunity to address the racial and ethnic disparities that currently exist in CF screening, diagnosis, and treatment. In addition to the previously documented disparate prevalence of the CFTR variant F508del in Hispanic patients, we observed two CFTR variants, p.His609Arg (legacy name H609R) and p.Thr1036Asn (legacy name T1036N), frequently identified in our Hispanic patients of Ecuadorian and Mexican ancestry, respectively, that are not well-described in the US population. The presence of population-specific and individually rare CFTR variants in Hispanic patients with CF further accentuates the disparity in health outcomes, as these CFTR variants are often absent from prenatal and NBS CFTR variant panels, potentially delaying diagnosis, and without an approved CFTR variant-specific therapy.
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Affiliation(s)
- Megan N Januska
- Department of Pulmonary, Critical Care, and Sleep Medicine, The Cystic Fibrosis Center at Mount Sinai Beth Israel, New York City, New York.,Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York City, New York
| | - Laura Marx
- Department of Pulmonary, Critical Care, and Sleep Medicine, The Cystic Fibrosis Center at Mount Sinai Beth Israel, New York City, New York.,Department of Pediatrics, Genetics and Metabolic Clinic, St. Luke's Children's Hospital, Boise, Idaho
| | - Patricia A Walker
- Department of Pulmonary, Critical Care, and Sleep Medicine, The Cystic Fibrosis Center at Mount Sinai Beth Israel, New York City, New York
| | - Maria N Berdella
- Department of Pulmonary, Critical Care, and Sleep Medicine, The Cystic Fibrosis Center at Mount Sinai Beth Israel, New York City, New York.,Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York City, New York
| | - Elinor Langfelder-Schwind
- Department of Pulmonary, Critical Care, and Sleep Medicine, The Cystic Fibrosis Center at Mount Sinai Beth Israel, New York City, New York
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29
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Bergougnoux A, Lopez M, Girodon E. The Role of Extended CFTR Gene Sequencing in Newborn Screening for Cystic Fibrosis. Int J Neonatal Screen 2020; 6:23. [PMID: 33073020 PMCID: PMC7422980 DOI: 10.3390/ijns6010023] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 03/19/2020] [Indexed: 01/25/2023] Open
Abstract
There has been considerable progress in the implementation of newborn screening (NBS) programs for cystic fibrosis (CF), with DNA analysis being part of an increasing number of strategies. Thanks to advances in genomic sequencing technologies, CFTR-extended genetic analysis (EGA) by sequencing its coding regions has become affordable and has already been included as part of a limited number of core NBS programs, to the benefit of admixed populations. Based on results analysis of existing programs, the values and challenges of EGA are reviewed in the perspective of its implementation on a larger scale. Sensitivity would be increased at best by using EGA as a second tier, but this could be at the expense of positive predictive value, which improves, however, if EGA is applied after testing a variant panel. The increased detection of babies with an inconclusive diagnosis has proved to be a major drawback in programs using EGA. The lack of knowledge on pathogenicity and penetrance associated with numerous variants hinders the introduction of EGA as a second tier, but EGA with filtering for all known CF variants with full penetrance could be a solution. The issue of incomplete knowledge is a real challenge in terms of the implemention of NBS extended to many genetic diseases.
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Affiliation(s)
- Anne Bergougnoux
- Molecular Genetics Laboratory, CHU Montpellier, EA7402 University of Montpellier, 34093 Montpellier CEDEX 5, France;
| | - Maureen Lopez
- Molecular Genetics Laboratory, Cochin Hospital, APHP. Centre, University of Paris, 75014 Paris, France;
| | - Emmanuelle Girodon
- Molecular Genetics Laboratory, Cochin Hospital, APHP. Centre, University of Paris, 75014 Paris, France;
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30
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Hannah WB, Truty R, Gonzales V, Kithcart GP, Ouyang K, Zeman MK, Li C, Drumm M, Nykamp K, Gaston BM. Frequency of Cystic Fibrosis Transmembrane Conductance Regulator Variants in Individuals Evaluated for Primary Ciliary Dyskinesia. J Pediatr 2019; 215:172-177.e2. [PMID: 31610925 DOI: 10.1016/j.jpeds.2019.08.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 08/17/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To evaluate whether cystic fibrosis transmembrane conductance regulator (CFTR) variants are more common among individuals tested for primary ciliary dyskinesia (PCD) compared with controls. STUDY DESIGN Data were studied from 1021 individuals with commercial genetic testing for suspected PCD and 91 777 controls with genetic testing at the same company (Invitae) for symptoms/diseases unrelated to PCD or CFTR testing. The prevalence of CFTR variants was compared between controls and each of 3 groups of individuals tested for PCD (PCD-positive, -uncertain, and -negative molecular diagnosis). RESULTS The prevalence of 1 pathogenic CFTR variant was similar among the individual groups. When combining the PCD-uncertain and PCR-negative molecular diagnosis groups, there was a higher prevalence of single pathogenic CFTR variants compared with controls (P = .03). Importantly, >1% of individuals who had negative genetic testing results for PCD had 2 pathogenic CFTR variants (8 of 723), and the incidence of cystic fibrosis (CF) (2 pathogenic variants) is roughly 1 in 3000 individuals of Caucasian ethnicity (∼0.03%). This incidence was also greater than that of 2 pathogenic CFTR variants in the control population (0.09% [84 of 91 777]; P = 9.60 × 10-16). These variants correlate with mild CFTR-related disease. CONCLUSIONS Our results suggest that a single pathogenic CFTR variant is not likely to be a PCD-mimetic, but ongoing studies are needed in individuals in whom PCD is suspected and genetic testing results are uncertain or negative. Furthermore, CF may be misdiagnosed as PCD, reflecting phenotypic overlap. Among individuals evaluated for PCD, CF should be considered in the differential even in the CF newborn screening era.
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Affiliation(s)
- William B Hannah
- Center for Human Genetics, University Hospitals Cleveland Medical Center, Cleveland, OH; Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH.
| | | | - Virginia Gonzales
- Division of Pulmonology, Department of Pediatrics, Rainbow Babies and Children's Hospital, University Hospitals Cleveland Medical Center, Cleveland, OH
| | - Gregory P Kithcart
- Division of Pulmonology, Department of Pediatrics, Rainbow Babies and Children's Hospital, University Hospitals Cleveland Medical Center, Cleveland, OH
| | | | | | - Chun Li
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH
| | - Mitchell Drumm
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH; Division of Pulmonology, Department of Pediatrics, Rainbow Babies and Children's Hospital, University Hospitals Cleveland Medical Center, Cleveland, OH
| | | | - Benjamin M Gaston
- Division of Pulmonology, Department of Pediatrics, Rainbow Babies and Children's Hospital, University Hospitals Cleveland Medical Center, Cleveland, OH
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Southern K, Barben J, Gartner S, Munck A, Castellani C, Mayell S, Davies J, Winters V, Murphy J, Salinas D, McColley S, Ren C, Farrell P. Inconclusive diagnosis after a positive newborn bloodspot screening result for cystic fibrosis; clarification of the harmonised international definition. J Cyst Fibros 2019; 18:778-780. [DOI: 10.1016/j.jcf.2019.04.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/10/2019] [Accepted: 04/10/2019] [Indexed: 02/08/2023]
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32
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Doull I. Devil in the detail of newborn screening for cystic fibrosis. Arch Dis Child 2019; 104:938-940. [PMID: 30389674 DOI: 10.1136/archdischild-2018-316247] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 10/18/2018] [Accepted: 10/21/2018] [Indexed: 11/03/2022]
Affiliation(s)
- Iolo Doull
- Department of Paediatric Respiratory Medicine and Paediatric Cystic, Childrens Hospital for Wales, Cardiff, UK.,Welsh Health Specialist Services, Caerphilly, UK
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33
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Boussaroque A, Bergougnoux A, Raynal C, Audrézet M, Sasorith S, Férec C, Bienvenu T, Girodon E. Pitfalls in the interpretation of
CFTR
variants in the context of incidental findings. Hum Mutat 2019; 40:2239-2246. [DOI: 10.1002/humu.23884] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 07/24/2019] [Accepted: 07/24/2019] [Indexed: 12/29/2022]
Affiliation(s)
- Agathe Boussaroque
- Laboratoire de Génétique et Biologie Moléculaires, AP‐HP, Hôpital CochinHUPC Paris France
| | - Anne Bergougnoux
- Laboratoire de Génétique MoléculaireCHU de Montpellier Montpellier France
| | - Caroline Raynal
- Laboratoire de Génétique MoléculaireCHU de Montpellier Montpellier France
| | | | - Souphatta Sasorith
- Laboratoire de Génétique MoléculaireCHU de Montpellier Montpellier France
| | - Claude Férec
- Laboratoire de Génétique MoléculaireCHU de Brest Brest France
| | - Thierry Bienvenu
- Laboratoire de Génétique et Biologie Moléculaires, AP‐HP, Hôpital CochinHUPC Paris France
| | - Emmanuelle Girodon
- Laboratoire de Génétique et Biologie Moléculaires, AP‐HP, Hôpital CochinHUPC Paris France
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34
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Course CW, Hanks R. Newborn screening for cystic fibrosis: Is there benefit for everyone? Paediatr Respir Rev 2019; 31:3-5. [PMID: 30956155 DOI: 10.1016/j.prrv.2019.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 02/20/2019] [Indexed: 10/27/2022]
Abstract
Newborn screening for cystic fibrosis (CF) has become a widely accepted and endorsed public health strategy in economically developed countries, although there is little consensus on optimal screening methods and gene panels. Increasing understanding of CFTR genetics and consequent unpredictability of phenotypic and clinical outcomes lead to diagnostic uncertainty, and emergence of Cystic Fibrosis Screen Positive Inconclusive Diagnosis (CF-SPID). Many of these children are clinically well or have a mild phenotype yet may still experience the psychosocial impact of a CF diagnosis. This questions the role of newborn screening and how best to manage those it identifies with CF-SPID.
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Affiliation(s)
- C W Course
- Department of Paediatric Respiratory Medicine and Cystic Fibrosis, Children's Hospital for Wales, Cardiff, United Kingdom.
| | - R Hanks
- Department of Paediatric Respiratory Medicine and Cystic Fibrosis, Children's Hospital for Wales, Cardiff, United Kingdom
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35
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Thauvin-Robinet C, Thevenon J, Nambot S, Delanne J, Kuentz P, Bruel AL, Chassagne A, Cretin E, Pelissier A, Peyron C, Gautier E, Lehalle D, Jean-Marçais N, Callier P, Mosca-Boidron AL, Vitobello A, Sorlin A, Tran Mau-Them F, Philippe C, Vabres P, Demougeot L, Poé C, Jouan T, Chevarin M, Lefebvre M, Bardou M, Tisserant E, Luu M, Binquet C, Deleuze JF, Verstuyft C, Duffourd Y, Faivre L. Secondary actionable findings identified by exome sequencing: expected impact on the organisation of care from the study of 700 consecutive tests. Eur J Hum Genet 2019; 27:1197-1214. [PMID: 31019283 DOI: 10.1038/s41431-019-0384-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 02/08/2019] [Accepted: 03/05/2019] [Indexed: 01/08/2023] Open
Abstract
With exome/genome sequencing (ES/GS) integrated into the practice of medicine, there is some potential for reporting incidental/secondary findings (IFs/SFs). The issue of IFs/SFs has been studied extensively over the last 4 years. In order to evaluate their implications in care organisation, we retrospectively evaluated, in a cohort of 700 consecutive probands, the frequency and burden of introducing the search for variants in a maximum list of 244 medically actionable genes (genes that predispose carriers to a preventable or treatable disease in childhood/adulthood and genes for genetic counselling issues). We also focused on the 59 PharmGKB class IA/IB pharmacogenetic variants. We also compared the results in different gene lists. We identified variants (likely) affecting protein function in genes for care in 26 cases (3.7%) and heterozygous variants in genes for genetic counselling in 29 cases (3.8%). Mean time for the 700 patients was about 6.3 min/patient for medically actionable genes and 1.3 min/patient for genes for genetic counselling, and a mean time of 37 min/patients for the reinterpreted variants. These results would lead to all 700 pre-test counselling sessions being longer, to 55 post-test genetic consultations and to 27 secondary specialised medical evaluations. ES also detected 42/59 pharmacogenetic variants or combinations of variants in the majority of cases. An extremely low metabolizer status in genes relevant for neurodevelopmental disorders (CYP2C9 and CYP2C19) was found in 57/700 cases. This study provides information regarding the need to anticipate the implementation of genomic medicine, notably the work overload at various steps of the process.
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Affiliation(s)
- Christel Thauvin-Robinet
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France. .,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France. .,Centre de Génétique et Centre de Référence Maladies Rares 'Anomalies du Développement de l'Interrégion Est, Hôpital d'Enfants, Centre Hospitalier Universitaire Dijon-Bourgogne, Dijon, France. .,UF Innovation en diagnostic génomique des maladies rares, CHU Dijon, Dijon, France.
| | - Julien Thevenon
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France.,Centre de Génétique et Centre de Référence Maladies Rares 'Anomalies du Développement de l'Interrégion Est, Hôpital d'Enfants, Centre Hospitalier Universitaire Dijon-Bourgogne, Dijon, France.,UF Innovation en diagnostic génomique des maladies rares, CHU Dijon, Dijon, France
| | - Sophie Nambot
- Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France.,Centre de Génétique et Centre de Référence Maladies Rares 'Anomalies du Développement de l'Interrégion Est, Hôpital d'Enfants, Centre Hospitalier Universitaire Dijon-Bourgogne, Dijon, France
| | - Julian Delanne
- Centre de Génétique et Centre de Référence Maladies Rares 'Anomalies du Développement de l'Interrégion Est, Hôpital d'Enfants, Centre Hospitalier Universitaire Dijon-Bourgogne, Dijon, France
| | - Paul Kuentz
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France
| | - Ange-Line Bruel
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France.,UF Innovation en diagnostic génomique des maladies rares, CHU Dijon, Dijon, France
| | - Aline Chassagne
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,CIC-IT Inserm 808, Centre Hospitalier Universitaire de Besançon et Université de Bourgogne-Franche Comté, Besançon, France
| | - Elodie Cretin
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,CIC-IT Inserm 808, Centre Hospitalier Universitaire de Besançon et Université de Bourgogne-Franche Comté, Besançon, France
| | - Aurore Pelissier
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,EES-LEDI, Université de Bourgogne - UMR CNRS INSERM, Dijon, France
| | - Chritine Peyron
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,EES-LEDI, Université de Bourgogne - UMR CNRS INSERM, Dijon, France
| | - Elodie Gautier
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France
| | - Daphné Lehalle
- Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France.,Centre de Génétique et Centre de Référence Maladies Rares 'Anomalies du Développement de l'Interrégion Est, Hôpital d'Enfants, Centre Hospitalier Universitaire Dijon-Bourgogne, Dijon, France
| | - Nolwenn Jean-Marçais
- Centre de Génétique et Centre de Référence Maladies Rares 'Anomalies du Développement de l'Interrégion Est, Hôpital d'Enfants, Centre Hospitalier Universitaire Dijon-Bourgogne, Dijon, France
| | - Patrick Callier
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France.,UF Innovation en diagnostic génomique des maladies rares, CHU Dijon, Dijon, France
| | - Anne-Laure Mosca-Boidron
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France.,UF Innovation en diagnostic génomique des maladies rares, CHU Dijon, Dijon, France
| | - Antonio Vitobello
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France.,UF Innovation en diagnostic génomique des maladies rares, CHU Dijon, Dijon, France
| | - Arthur Sorlin
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France.,Centre de Génétique et Centre de Référence Maladies Rares 'Anomalies du Développement de l'Interrégion Est, Hôpital d'Enfants, Centre Hospitalier Universitaire Dijon-Bourgogne, Dijon, France.,UF Innovation en diagnostic génomique des maladies rares, CHU Dijon, Dijon, France
| | - Frédéric Tran Mau-Them
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France.,UF Innovation en diagnostic génomique des maladies rares, CHU Dijon, Dijon, France
| | - Christophe Philippe
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France.,UF Innovation en diagnostic génomique des maladies rares, CHU Dijon, Dijon, France
| | - Pierre Vabres
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France
| | - Laurent Demougeot
- Filière AnDDI-Rares, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France
| | - Charlotte Poé
- Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France
| | - Thibaud Jouan
- Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France
| | - Martin Chevarin
- Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France
| | - Mathilde Lefebvre
- Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France.,Centre de Génétique et Centre de Référence Maladies Rares 'Anomalies du Développement de l'Interrégion Est, Hôpital d'Enfants, Centre Hospitalier Universitaire Dijon-Bourgogne, Dijon, France
| | - Marc Bardou
- CIC-EC 1432, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France
| | - Emilie Tisserant
- Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France
| | - Maxime Luu
- CIC-EC 1432, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France
| | - Christine Binquet
- CIC-EC 1432, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France
| | | | - Céline Verstuyft
- CESP/UMR-S1178, Equipe "Dépression et Antidépresseurs", Université Paris-Sud, Faculté de Médecine, Université Paris-Saclay, et Service de Génétique Moléculaire, Pharmacogénétique et Hormonologie, Hôpital Bicêtre, AP-HP, Le Kremlin-Bicêtre, France
| | - Yannis Duffourd
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France.,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France
| | - Laurence Faivre
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France. .,Inserm UMR 1231 GAD « Génétique des Anomalies du Développement », Université de Bourgogne, Dijon, France. .,Centre de Génétique et Centre de Référence Maladies Rares 'Anomalies du Développement de l'Interrégion Est, Hôpital d'Enfants, Centre Hospitalier Universitaire Dijon-Bourgogne, Dijon, France. .,Centre National de Recherche en Génomique Humaine, Evry, France.
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Cystic fibrosis screen positive inconclusive diagnosis (CFSPID): Experience in Tuscany, Italy. J Cyst Fibros 2019; 18:484-490. [PMID: 31005549 DOI: 10.1016/j.jcf.2019.04.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 04/01/2019] [Accepted: 04/01/2019] [Indexed: 11/23/2022]
Abstract
OBJECTIVE The implementation of cystic fibrosis (CF) newborn screening (NBS) has led to identification of infants with a positive NBS test but inconclusive diagnosis classified as "CF screen positive, inconclusive diagnosis" (CFSPID). We retrospectively evaluated the prevalence and clinical outcome of CFSPID infants diagnosed by 2 NBS algorithms in the period from 2011 to 2016 in the Tuscany region of Italy. METHODS In 2011-2016, we assessed the diagnostic impact of DNA analysis on the NBS 4-tier algorithm [immunoreactive trypsin (IRT) - meconium lactase - IRT2 - sweat chloride (SC)]. All CFSPID patients repeated SC testing every 6 months, and CFTR gene analysis was performed (detection rate 98%). We reclassified children as: CF diagnosis in presence of at least 2 pathological SC results; healthy carrier or healthy in presence of at least 2 normal SC results for age and either 1 or 0 CF-causing mutations, respectively. RESULTS We identified 32 CF and 50 CFSPID cases: 20/50 (40%) were diagnosed only by the IRT-DNA-SC algorithm and 16/50 (32%) only by IRT-meconium lactase-IRT2-SC. Both protocols identified the remaining 14 cases (28%). Thirty-seven of 50 (74%) CFSPID patients had a conclusive diagnosis on December 31, 2017:5 (10%) CF, 17 (34%) healthy and 15 (30%) healthy carriers; 13/50 (26%) cases were asymptomatic with persistent intermediate SC and followed as CFSPID (CF:CFSPID ratio 2.85:1). CONCLUSIONS In 6 years, the CF:CFSPID ratio modified from 0.64:1 to 2.85:1, and 10% of CFSPID cases progressed to CF. Genetic analysis improved positive predictive value and identified a higher number of CFSPID infants progressing to CF.
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Welsner M, Straßburg S, Taube C, Sutharsan S. Use of ivacaftor in late diagnosed cystic fibrosis monozygotic twins heterozygous for F508del and R117H-7T - a case report. BMC Pulm Med 2019; 19:76. [PMID: 30975115 PMCID: PMC6458608 DOI: 10.1186/s12890-019-0840-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 03/28/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND CFTR modulator therapy with ivacaftor is a treatment option for Cystic Fibrosis (CF) patients with at least one copy of a R117H-7T mutation in the CFTR gene. Desirable effects of this therapy are improvement of lung function, decrease in exacerbation rate, normalization or reduction of sweat chloride and weight gain. Monogenetic CF-twins carry identical genetic information, so therapy response and side effects are expected to be nearly identical under this specific therapy. CASE PRESENTATION In monozygotic twins, at the age of 55, two pathogenic variants in the CFTR gene (F508del and R117H-7T) were detected. Both patients presented with a borderline sweat test (30-59 mmol/L) and despite the same genetic information and similar life circumstances the disease proceeds completely different. While one patient has severe pulmonary involvement with chronic P. aeruginosa infection, her twin sister is almost unimpaired. Liver or pancreatic involvement was not seen in either patient. Due to the presence of one copy of a R117H-7T mutation, CFTR modulator therapy with ivacaftor was initiated in both. Response and side effects were significantly different. In the less affected patient, we observed an improvement in lung function and a normalization of sweat chloride. In the severely affected patient, no functional response to treatment was seen, but stabilization of the disease state with a decrease in exacerbation and hospitalization rate and weight gain as well as a normalization of sweat chloride. There was an increase in liver enzymes in the less affected patient, which normalized after halving the dose of ivacaftor, while the therapeutic effect was maintained. CONCLUSIONS Despite nearly identical genetic information, as in monogenetic twins, therapy response and onset of side effects of CFTR modulating therapy are very different. In patients with late diagnosis and severe pulmonary involvement, ivacaftor does not seem to improve lung function, whereas in patients with late diagnosis and low disease severity a relevant therapy response was obtained. In addition to lung function, additional clinical parameters such as reduction of exacerbation and hospitalization rate and weight gain should be used to assess therapy response, especially in severely affected patients.
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Affiliation(s)
- Matthias Welsner
- Department of Pulmonary Medicine, University Hospital Essen - Ruhrlandklinik, Adult Cystic Fibrosis Center, University of Duisburg-Essen, Tueschener Weg 40, 45329, Essen, Germany.
| | - Svenja Straßburg
- Department of Pulmonary Medicine, University Hospital Essen - Ruhrlandklinik, Adult Cystic Fibrosis Center, University of Duisburg-Essen, Tueschener Weg 40, 45329, Essen, Germany
| | - Christian Taube
- Department of Pulmonary Medicine, University Hospital Essen - Ruhrlandklinik, Adult Cystic Fibrosis Center, University of Duisburg-Essen, Tueschener Weg 40, 45329, Essen, Germany
| | - Sivagurunathan Sutharsan
- Department of Pulmonary Medicine, University Hospital Essen - Ruhrlandklinik, Adult Cystic Fibrosis Center, University of Duisburg-Essen, Tueschener Weg 40, 45329, Essen, Germany
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Keenan K, Dupuis A, Griffin K, Castellani C, Tullis E, Gonska T. Phenotypic spectrum of patients with cystic fibrosis and cystic fibrosis-related disease carrying p.Arg117His. J Cyst Fibros 2019; 18:265-270. [DOI: 10.1016/j.jcf.2018.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/31/2018] [Accepted: 09/03/2018] [Indexed: 12/20/2022]
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Newborn blood spot screening for cystic fibrosis with a four-step screening strategy in the Netherlands. J Cyst Fibros 2019; 18:54-63. [DOI: 10.1016/j.jcf.2018.07.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 07/09/2018] [Accepted: 07/16/2018] [Indexed: 12/27/2022]
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40
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Fournier T, Schacherer J. Genetic backgrounds and hidden trait complexity in natural populations. Curr Opin Genet Dev 2017; 47:48-53. [PMID: 28915487 PMCID: PMC5716861 DOI: 10.1016/j.gde.2017.08.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/09/2017] [Accepted: 08/31/2017] [Indexed: 11/29/2022]
Abstract
Dissecting the genetic basis of natural phenotypic variation is a major goal in biology. We know that most traits are strongly heritable. However, their genetic architecture is a long-standing question, which is unfortunately confounded by the lack of complete knowledge of the genetic components as well as their phenotypic effect in a specific genetic background. Many genetic variants are known to affect phenotypes but the same functional variant can have a different effect on the phenotype in different individuals of the same species. Understanding the impact of genetic background on the expressivity of a given phenotype is essential because this effect complicates our ability to predict phenotype from genotype. Here, we briefly review recent progress on the exploration of the effect of genetic background and we discuss how a deeper characterization of the inheritance, expressivity and genetic interactions hidden behind the phenotypic landscape of natural variation could provide a better understanding of the relationship between genotype and phenotype.
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Affiliation(s)
- Téo Fournier
- Université de Strasbourg, CNRS, GMGM UMR 7156, F-67000 Strasbourg, France
| | - Joseph Schacherer
- Université de Strasbourg, CNRS, GMGM UMR 7156, F-67000 Strasbourg, France.
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41
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Sermet-Gaudelus I, Brouard J, Audrézet MP, Couderc Kohen L, Weiss L, Wizla N, Vrielynck S, LLerena K, Le Bourgeois M, Deneuville E, Remus N, Nguyen-Khoa T, Raynal C, Roussey M, Girodon E. Guidelines for the clinical management and follow-up of infants with inconclusive cystic fibrosis diagnosis through newborn screening. Arch Pediatr 2017; 24:e1-e14. [PMID: 29174009 DOI: 10.1016/j.arcped.2017.07.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 06/21/2017] [Accepted: 07/04/2017] [Indexed: 01/17/2023]
Abstract
Neonatal screening for cystic fibrosis (CF) can detect infants with elevated immunoreactive trypsinogen (IRT) levels and inconclusive sweat tests and/or CFTR DNA results. These cases of uncertain diagnosis are defined by (1) either the presence of at most one CF-associated cystic fibrosis transmembrane conductance regulator (CFTR) mutation with sweat chloride values between 30 and 59mmol/L or (2) two CFTR mutations with at least one of unknown pathogenic potential and a sweat chloride concentration below 60mmol/L. This encompasses various clinical situations whose progression cannot be predicted. In these cases, a sweat chloride test has to be repeated at 12 months, and if possible at 6 and 24 months of life along with extended CFTR sequencing to detect rare mutations. When the diagnosis is not definite, CFTR functional explorations may provide a better understanding of CFTR dysfunction. The initial evaluation of these infants must be conducted in dedicated CF reference centers and should include bacteriological sputum analysis, chest radiology, and fecal elastase assay. The primary care physicians in charge of these patients should be familiar with the current management of CF and should work in collaboration with CF centers. A follow-up should be performed in a CF reference center at 3, 6, and 12 months of life and every year thereafter. Any symptom indicative of CF requires immediate reevaluation of the diagnosis. These guidelines were established by the "neonatal screening and difficult diagnoses" working group of the French CF society. Their objective is to standardize the management of infants with unclear diagnosis.
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Affiliation(s)
- I Sermet-Gaudelus
- Cystic fibrosis center, Necker-Enfants-Malades hospital, 75015 Paris, France; Inserm U1151, 75993 Paris, France.
| | - J Brouard
- Cystic fibrosis reference center, hôpital de la Côte-de-Nacre, 14033 Caen, France
| | - M-P Audrézet
- Molecular genetic laboratory, CHRU de Brest, 29609 Brest, France
| | - L Couderc Kohen
- Cystic fibrosis reference center, Charles-Nicolle hospital, 76000 Rouen, France
| | - L Weiss
- Cystic fibrosis reference center, Hautepierre hospital, 67200 Strasbourg, France
| | - N Wizla
- Cystic fibrosis reference center, Jeanne-de-Flandres hospital, 59000 Lille, France
| | - S Vrielynck
- Cystic fibrosis reference center, child and mother hospital, 69677 Lyon, France
| | - K LLerena
- Cystic fibrosis center, university hospital, 38700 Grenoble, France
| | - M Le Bourgeois
- Cystic fibrosis center, Necker-Enfants-Malades hospital, 75015 Paris, France
| | - E Deneuville
- Cystic fibrosis center, CHU de Rennes, 35000 Rennes, France
| | - N Remus
- Cystic fibrosis center, Créteil intercommunal hospital, 94000 Créteil, France
| | - T Nguyen-Khoa
- Cystic fibrosis center, Necker-Enfants-Malades hospital, 75015 Paris, France
| | - C Raynal
- UMR 5535, molecular genetic institute, 34293 Montpellier, France
| | - M Roussey
- Association française pour le dépistage et la prévention des handicaps de l'Enfant, 75015 Paris, France
| | - E Girodon
- Inserm U1151, 75993 Paris, France; Molecular genetics laboratory, Cochin hospital, 75014 Paris, France
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42
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Wagener JS, Millar SJ, Mayer-Hamblett N, Sawicki GS, McKone EF, Goss CH, Konstan MW, Morgan WJ, Pasta DJ, Moss RB. Lung function decline is delayed but not decreased in patients with cystic fibrosis and the R117H gene mutation. J Cyst Fibros 2017; 17:503-510. [PMID: 29100868 DOI: 10.1016/j.jcf.2017.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/29/2017] [Accepted: 10/03/2017] [Indexed: 11/18/2022]
Abstract
BACKGROUND Patients with cystic fibrosis (CF) experience variable lung disease phenotypes. The R117H mutation is often associated with preserved lung function. Our objective was to compare the rate of lung function decline in patients with the R117H mutation and patients homozygous for the F508del mutation. METHODS Rate of decline in percentage-of-predicted FEV1 (ppFEV1) was analyzed using the 2006-2010 US CF Foundation Patient Registry. RESULTS 4-year rate of decline was slower in 156 R117H patients compared with 6251 F508del patients (-0.61 vs -2.03 ppFEV1/year, P<0.001). Rates of decline in children were slower in R117H vs F508del patients (6-12-year-olds: +0.73 vs -1.91 ppFEV1/year, P<0.001 and 13-17-year-olds: -1.55 vs -2.66 ppFEV1/year, P=0.046), whereas rates in adults were not significantly different (18-24-year-olds: -1.52 vs -2.12, P=0.26 and ≥25-year-olds: -1.17 vs -1.40, P=0.33). CONCLUSIONS These findings are consistent with a delayed onset, but ultimately similar progression, of lung disease in R117H compared with homozygous F508del patients.
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Affiliation(s)
| | | | - Nicole Mayer-Hamblett
- US CFF Patient Registry Committee, Bethesda, MD, USA; Department of Pediatrics and Biostatistics, University of Washington, Seattle, WA, USA
| | - Gregory S Sawicki
- US CFF Patient Registry Committee, Bethesda, MD, USA; Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Edward F McKone
- Thoracic Medicine, St. Vincent's University Hospital, Dublin, Ireland
| | - Christopher H Goss
- US CFF Patient Registry Committee, Bethesda, MD, USA; Department of Medicine, University of Washington, Seattle, WA, USA
| | - Michael W Konstan
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA
| | - Wayne J Morgan
- US CFF Patient Registry Committee, Bethesda, MD, USA; Department of Pediatrics, University of Arizona, Tucson, AZ, USA
| | | | - Richard B Moss
- Department of Pediatrics, Stanford University, Palo Alto, CA, USA
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43
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De Boeck K, Vermeulen F, Dupont L. The diagnosis of cystic fibrosis. Presse Med 2017; 46:e97-e108. [PMID: 28576637 DOI: 10.1016/j.lpm.2017.04.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 04/18/2017] [Accepted: 04/27/2017] [Indexed: 01/09/2023] Open
Abstract
Establishing the diagnosis of cystic fibrosis (CF) is straight forward in the majority of patients: they present with a clear clinical picture (most frequently chronic respiratory symptoms plus malabsorption), the sweat chloride value is>60mmol/L and two known disease causing CFTR mutations are identified. In less than 5% of subjects, mainly those with a milder or limited phenotype, the diagnostic process is more complex, because initial diagnostic test results are inconclusive: sweat chloride concentration in the intermediate range, less than 2 CF causing mutations identified or both. These patients should be referred to expert centers where bioassays of CFTR function like nasal potential difference measurement or intestinal current measurement can be done. Still, in some patients, despite symptoms compatible with CF and some indication of CFTR dysfunction (e.g. only intermediate sweat chloride value), diagnostic criteria are not met (e.g. only 1 CFTR mutation identified). For these subjects, the term CFTR related disorder (CFTR-RD) is used. Patients with disseminated bronchiectasis, congenital bilateral absence of the vas deferens and acute or recurrent pancreatitis may fall in this category. CF has a very wide disease spectrum and increasingly the diagnosis is being made during adult life, mainly in subjects with milder phenotypes. In many countries, nationwide CF newborn screening (NBS) has been introduced. In screen positive babies, the diagnosis of CF must be confirmed by a sweat test demonstrating a sweat chloride concentration above 60mmol/L. To achieve the benefit of NBS, every baby in whom the diagnosis of CF is confirmed must receive immediate follow-up and treatment in a CF reference center. CF NBS is not full proof: some diagnoses will be missed and in some babies the diagnosis cannot be confirmed nor ruled out with certainty. Screening algorithms that include gene sequencing will detect a high number of such babies that are screen positive with an inconclusive diagnosis (CFSPID). Even in 2016, the most reliable and widely available diagnostic test for CF is the measurement of chloride concentration in sweat. The method of choice is sweat induction by pilocarpine iontophoresis, followed by sweat collection on a gauze or filter paper or in a Macroduct coil. Since mutation specific therapies have become available, it is important to identify the mutations responsible for CF in each individual patient.
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Affiliation(s)
- Kris De Boeck
- University of Leuven, Department of Pulmonology, 3000 Leuven, Belgium.
| | | | - Lieven Dupont
- University of Leuven, Department of Pulmonology, Leuven, Belgium
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44
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Sermet-Gaudelus I, Brouard J, Audrézet MP, Couderc Kohen L, Weiss L, Wizla N, Vrielynck S, LLerena K, Le Bourgeois M, Deneuville E, Remus N, Nguyen-Khoa T, Raynal C, Roussey M, Girodon E. [Management of infants whose diagnosis is inconclusive at neonatal screening for cystic fibrosis]. Arch Pediatr 2017; 24:401-414. [PMID: 28258861 DOI: 10.1016/j.arcped.2017.01.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 01/24/2017] [Accepted: 01/24/2017] [Indexed: 10/20/2022]
Abstract
Neonatal screening for cystic fibrosis (CF) may detect infants with elevated immunoreactive trypsinogen (IRT) levels but with inconclusive sweat tests and/or DNA results. This includes cases associating (1) either the presence of at most one CF-causing mutation and sweat chloride values between 30 and 59mmol/L or (2) two CFTR mutations with at least one of unknown pathogenicity and a sweat chloride below 60mmol/L. This encompasses different clinical situations whose progression cannot be predicted. These cases require redoing the sweat test at 12 months and if possible at 6 and 24 months of life. This must be associated with extended genotyping. CFTR functional explorations can also help by investigating CFTR dysfunction. These infants must be initially evaluated in dedicated CF centers including bacteriological sputum analysis, chest radiology and fecal elastase dosage. A home practitioner must be informed of the specificity of follow-up. These infants will be reviewed in the CF center at 3, 6 and 12 months and every year. Any CF-related symptom requires reevaluation of the diagnosis. These guidelines were established by the "neonatal screening and difficult diagnoses" working group of the French CF Society. They aim to standardize management of infants with unclear diagnosis in French CF centers.
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Affiliation(s)
- I Sermet-Gaudelus
- Centre de ressources et de compétences en mucoviscidose, hôpital Necker-Enfants Malades, 149, rue de Sévres, 75015 Paris, France; Inserm U 1151, Paris, France.
| | - J Brouard
- Centre de ressources et de compétences en mucoviscidose, hôpital de la Côte-de-Nacre, 14033 Caen, France
| | - M-P Audrézet
- Laboratoire de génétique moléculaire, CHRU de Brest, 29609 Brest, France
| | - L Couderc Kohen
- Centre de ressources et de compétences en mucoviscidose, hôpital Charles-Nicolle, 76000 Rouen, France
| | - L Weiss
- Centre de ressources et de compétences en mucoviscidose, hôpital de Hautepierre, 67200 Strasbourg, France
| | - N Wizla
- Centre de ressources et de compétences en mucoviscidose, hôpital Jeanne-de-Flandres, 59000 Lille, France
| | - S Vrielynck
- Centre de ressources et de compétences en mucoviscidose, hôpital Mère-Enfant, 69677 Lyon, France
| | - K LLerena
- Centre de ressources et de compétences en mucoviscidose, CHU, 38700 Grenoble, France
| | - M Le Bourgeois
- Centre de ressources et de compétences en mucoviscidose, hôpital Necker-Enfants Malades, 149, rue de Sévres, 75015 Paris, France
| | - E Deneuville
- Centre de ressources et de compétences en mucoviscidose, CHU, 35000 Rennes, France
| | - N Remus
- Centre de ressources et de compétences en mucoviscidose, hôpital InterCommunal de Créteil, 94000 Créteil, France
| | - T Nguyen-Khoa
- Centre de ressources et de compétences en mucoviscidose, hôpital Necker-Enfants Malades, 149, rue de Sévres, 75015 Paris, France
| | - C Raynal
- Institut de génétique moléculaire, UMR 5535, 34293 Montpellier, France
| | - M Roussey
- Association française pour le dépistage et la prévention des handicaps de l'enfant, 75015 Paris, France
| | - E Girodon
- Laboratoire de génétique moléculaire, hôpital Cochin, 75014 Paris, France
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45
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Farrell PM, White TB, Howenstine MS, Munck A, Parad RB, Rosenfeld M, Sommerburg O, Accurso FJ, Davies JC, Rock MJ, Sanders DB, Wilschanski M, Sermet-Gaudelus I, Blau H, Gartner S, McColley SA. Diagnosis of Cystic Fibrosis in Screened Populations. J Pediatr 2017; 181S:S33-S44.e2. [PMID: 28129810 DOI: 10.1016/j.jpeds.2016.09.065] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Cystic fibrosis (CF) can be difficult to diagnose, even when newborn screening (NBS) tests yield positive results. This challenge is exacerbated by the multitude of NBS protocols, misunderstandings about screening vs diagnostic tests, and the lack of guidelines for presumptive diagnoses. There is also confusion regarding the designation of age at diagnosis. STUDY DESIGN To improve diagnosis and achieve standardization in definitions worldwide, the CF Foundation convened a committee of 32 experts with a mission to develop clear and actionable consensus guidelines on diagnosis of CF with an emphasis on screened populations, especially the newborn population. A comprehensive literature review was performed with emphasis on relevant articles published during the past decade. RESULTS After reviewing the common screening protocols and outcome scenarios, 14 of 27 consensus statements were drafted that apply to screened populations. These were approved by 80% or more of the participants. CONCLUSIONS It is recommended that all diagnoses be established by demonstrating dysfunction of the CF transmembrane conductance regulator (CFTR) channel, initially with a sweat chloride test and, when needed, potentially with newer methods assessing membrane transport directly, such as intestinal current measurements. Even in babies with 2 CF-causing mutations detected via NBS, diagnosis must be confirmed by demonstrating CFTR dysfunction. The committee also recommends that the latest classifications identified in the Clinical and Functional Translation of CFTR project [http://www.cftr2.org/index.php] should be used to aid with CF diagnosis. Finally, to avoid delays in treatment, we provide guidelines for presumptive diagnoses and recommend how to determine the age of diagnosis.
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Affiliation(s)
- Philip M Farrell
- Departments of Pediatrics and Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | | | - Michelle S Howenstine
- Section of Pediatric Pulmonology, Allergy, and Sleep Medicine, Indiana University School of Medicine, Riley Hospital for Children, Indianapolis, IN
| | - Anne Munck
- Centres de Ressources et de Compétences pour la Mucoviscidose, Hôpital Robert Debre, Paris, France
| | - Richard B Parad
- Department of Pediatric and Newborn Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA
| | - Margaret Rosenfeld
- Department of Pediatrics, Seattle Children's Research Institute, University of Washington School of Medicine, Seattle, WA
| | | | - Frank J Accurso
- Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO
| | - Jane C Davies
- Pediatric Respirology and Experimental Medicine, Imperial College London and Pediatric Respiratory Medicine, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom
| | - Michael J Rock
- Departments of Pediatrics and Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Don B Sanders
- Department of Pediatrics, Section of Pediatric Pulmonology, Allergy and Sleep Medicine, Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, IN
| | - Michael Wilschanski
- Pediatric Gastroenterology, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Isabelle Sermet-Gaudelus
- Institut Necker Enfants Malades/INSERM U1151, Hôpital Necker Enfants Malades, Centres de Ressources et de Compétences pour la Mucoviscidose, Paris, France
| | - Hannah Blau
- Sackler Faculty of Medicine, Graub Cystic Fibrosis Center, Pulmonary Institute Schneider Children's Medical Center of Israel, Petah Tikva, Tel Aviv University, Tel Aviv, Israel
| | | | - Susanna A McColley
- Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL
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46
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Sosnay PR, Salinas DB, White TB, Ren CL, Farrell PM, Raraigh KS, Girodon E, Castellani C. Applying Cystic Fibrosis Transmembrane Conductance Regulator Genetics and CFTR2 Data to Facilitate Diagnoses. J Pediatr 2017; 181S:S27-S32.e1. [PMID: 28129809 DOI: 10.1016/j.jpeds.2016.09.063] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE As a Mendelian disease, genetics plays an integral role in the diagnosis of cystic fibrosis (CF). The identification of 2 disease-causing mutations in the CF transmembrane conductance regulator (CFTR) in an individual with a phenotype provides evidence that the disease is CF. However, not all variations in CFTR always result in CF. Therefore, for CFTR genotype to provide the same level of evidence of CFTR dysfunction as shown by direct tests such as sweat chloride or nasal potential difference, the mutations identified must be known to always result in CF. The use of CFTR genetics in CF diagnosis, therefore, relies heavily on mutation interpretation. STUDY DESIGN Progress that has been made on mutation interpretation and annotation was reviewed at the recent CF Foundation Diagnosis Consensus Conference. A modified Delphi method was used to identify consensus statements on the use of genetic analysis in CF diagnosis. RESULTS The largest recent advance in CF genetics has come through the Clinical and Functional Translation of CFTR (CFTR2) project. This undertaking seeks to characterize CFTR mutations from patients with CF around the world. The project also established guidelines for the clinical, functional, and population/penetrance criteria that can be used to interpret mutations not yet included in CFTR2's review. CONCLUSIONS The use of CFTR genetics to aid in diagnosis of CF requires that the mutations identified have a known disease liability. The demonstration of 2 in trans mutations known to always result in CF is satisfactory evidence of CFTR dysfunction. However, if the identified mutations are known to be associated with variable outcomes, or have unknown consequence, that genotype may not result in a CF phenotype. In these cases, other tests of CFTR function may help.
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Affiliation(s)
- Patrick R Sosnay
- Department of Medicine, Division of Pulmonary and Critical Care Medicine and McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Danieli B Salinas
- Department of Pediatrics, Division of Pediatric Pulmonology, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | | | - Clement L Ren
- Section of Pediatric Pulmonology, Allergy, and Sleep Medicine, Indiana University School of Medicine, Indianapolis, IN
| | - Philip M Farrell
- Departments of Pediatrics and Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Karen S Raraigh
- McKusick-Nathans Institute of Medical Genetics, Johns Hopkins University School of Medicine, Johns Hopkins University, Baltimore, MD
| | - Emmanuelle Girodon
- Service de Génétique et Biologie Moléculaires, Groupe Hospitalier Cochin - Broca - Hôtel Dieu, Paris, France
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47
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Farrell PM, White TB, Ren CL, Hempstead SE, Accurso F, Derichs N, Howenstine M, McColley SA, Rock M, Rosenfeld M, Sermet-Gaudelus I, Southern KW, Marshall BC, Sosnay PR. Diagnosis of Cystic Fibrosis: Consensus Guidelines from the Cystic Fibrosis Foundation. J Pediatr 2017; 181S:S4-S15.e1. [PMID: 28129811 DOI: 10.1016/j.jpeds.2016.09.064] [Citation(s) in RCA: 481] [Impact Index Per Article: 68.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Cystic fibrosis (CF), caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, continues to present diagnostic challenges. Newborn screening and an evolving understanding of CF genetics have prompted a reconsideration of the diagnosis criteria. STUDY DESIGN To improve diagnosis and achieve standardized definitions worldwide, the CF Foundation convened a committee of 32 experts in CF diagnosis from 9 countries to develop clear and actionable consensus guidelines on the diagnosis of CF and to clarify diagnostic criteria and terminology for other disorders associated with CFTR mutations. An a priori threshold of ≥80% affirmative votes was required for acceptance of each recommendation statement. RESULTS After reviewing relevant literature, the committee convened to review evidence and cases. Following the conference, consensus statements were developed by an executive subcommittee. The entire consensus committee voted and approved 27 of 28 statements, 7 of which needed revisions and a second round of voting. CONCLUSIONS It is recommended that diagnoses associated with CFTR mutations in all individuals, from newborn to adult, be established by evaluation of CFTR function with a sweat chloride test. The latest mutation classifications annotated in the Clinical and Functional Translation of CFTR project (http://www.cftr2.org/index.php) should be used to aid in diagnosis. Newborns with a high immunoreactive trypsinogen level and inconclusive CFTR functional and genetic testing may be designated CFTR-related metabolic syndrome or CF screen positive, inconclusive diagnosis; these terms are now merged and equivalent, and CFTR-related metabolic syndrome/CF screen positive, inconclusive diagnosis may be used. International Statistical Classification of Diseases and Related Health Problems, 10th Revision codes for use in diagnoses associated with CFTR mutations are included.
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Affiliation(s)
- Philip M Farrell
- Departments of Pediatrics and Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | | | - Clement L Ren
- Section of Pediatric Pulmonology, Allergy, and Sleep Medicine, Indiana University School of Medicine, Riley Hospital for Children, Indianapolis, IN
| | | | - Frank Accurso
- Section of Pediatric Pulmonology, Colorado School of Public Health, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO
| | - Nico Derichs
- CFTR Biomarker Center and Translational CF Research Group, CF Center, Pediatric Pulmonology and Immunology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Michelle Howenstine
- Section of Pediatric Pulmonology, Allergy, and Sleep Medicine, Indiana University School of Medicine, Riley Hospital for Children, Indianapolis, IN
| | - Susanna A McColley
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, and Division of Pulmonary Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL
| | - Michael Rock
- Departments of Pediatrics and Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Margaret Rosenfeld
- Seattle Children's Research Institute and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA
| | - Isabelle Sermet-Gaudelus
- Centres de Ressources et de Compétences pour la Mucoviscidose, Institut Necker Enfants Malades/INSERM U1151, Hôpital Necker Enfants Malades, Paris, France
| | - Kevin W Southern
- Department of Women's and Children's Health, University of Liverpool, Institute in the Park, Alder Hey Children's Hospital, Liverpool, United Kingdom
| | | | - Patrick R Sosnay
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University, Baltimore, MD
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Shteinberg M, Downey DG, Beattie D, McCaughan J, Reid A, Stein N, Elborn JS. Lung function and disease severity in cystic fibrosis patients heterozygous for p.Arg117His. ERJ Open Res 2017; 3:00056-2016. [PMID: 28845426 PMCID: PMC5566269 DOI: 10.1183/23120541.00056-2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 01/19/2017] [Indexed: 01/20/2023] Open
Abstract
Expression of p.Arg117His cystic fibrosis (CF) transmembrane conductance regulator is influenced by a polythymidine (poly-T) tract and a thymidine-guanine (TG) repeat on intron 9, which vary in length and affect exon 10 skipping. We compared clinical characteristics and the rate of progression of lung disease of CF patients carrying the p.Arg117His mutation with different intron 9 varying sequences (poly-T) and mutation classes in trans. Data were collected from patients in Northern Ireland, UK, including diagnostic features, sweat chloride, nutritional status, sputum microbiology, CF-related complications and lung function. Poly-T and TG repeats were determined by PCR. Forced expiratory volume in 1 s (FEV1) decline was determined from linear regression of FEV1 measurements of patients over time. We identified 62 patients with p.Arg117His, 55 with a class I/II mutation in trans and six with p.Arg117His/p.Gly551Asp. 42 patients had 5T and 13 had 7T. All patients had 12 TG repeats. Patients with p.Arg117His-5T had greater lung function decline, sweat chloride concentrations, pancreatic insufficiency and prevalence of Pseudomonas aeruginosa infection compared with patients with p.Arg117His-7T. Lung function decline and disease severity in p.Arg117His is determined by the poly-T tract length and identity of the mutation in trans. Patients with p.Arg117His-5T and a second class I/II mutation have a severity similar to p.Phe508del homozygous patients, although lung function decline is delayed to an older age. There may be linkage disequilibrium between p.Arg117His and 12 TG repeats.
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Affiliation(s)
- Michal Shteinberg
- Northern Ireland Regional Adult Cystic Fibrosis Centre, Belfast Health and Social Care Trust, Belfast, UK
- Pulmonology and CF Center, Carmel Medical Center and Rappaport Faculty of Medicine, Haifa, Israel
- Queen's University of Belfast, Belfast, UK
| | - Damian G. Downey
- Northern Ireland Regional Adult Cystic Fibrosis Centre, Belfast Health and Social Care Trust, Belfast, UK
- Queen's University of Belfast, Belfast, UK
| | - Diane Beattie
- Northern Ireland Regional Adult Cystic Fibrosis Centre, Belfast Health and Social Care Trust, Belfast, UK
| | - John McCaughan
- Northern Ireland Regional Paediatric Cystic Fibrosis Centre, Royal Belfast Hospital for Sick Children, Belfast Health and Social Care Trust, Belfast, UK
| | - Alastair Reid
- Northern Ireland Regional Paediatric Cystic Fibrosis Centre, Royal Belfast Hospital for Sick Children, Belfast Health and Social Care Trust, Belfast, UK
| | - Nili Stein
- Pulmonology and CF Center, Carmel Medical Center and Rappaport Faculty of Medicine, Haifa, Israel
| | - J. Stuart Elborn
- Northern Ireland Regional Adult Cystic Fibrosis Centre, Belfast Health and Social Care Trust, Belfast, UK
- Queen's University of Belfast, Belfast, UK
- Imperial College and Royal Brompton Hospital, London, UK
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49
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Abstract
INTRODUCTION Mutations in the cystic fibrosis transmembrane conductance regulator protein (CFTR) cause cystic fibrosis (CF), a disease with life threatening pulmonary and gastrointestinal manifestations. Recent breakthrough therapies restore function to select disease-causing CFTR mutations. Ivacaftor is a small molecule that increases the open channel probability of certain CFTR mutations, producing clear evidence of bioactivity and efficacy in pediatric CF patients. CFTR modulators represent a significant advancement in CF treatment. Extending these therapies to young CF patients is proposed to have the greatest long term impact, potentially preventing later disease. AREAS COVERED Here we summarize the research experience of CFTR modulators in pediatrics, focusing on ivacaftor and highlighting challenges in pediatric studies. As a result of these studies, ivacaftor has been approved in CF patients age 2 years and older who have one of ten CFTR mutations. EXPERT OPINION Conducting studies in young CF patients presents unique challenges, including small numbers of patients and difficulty selecting sensitive biomarkers and meaningful outcome measures. Adverse events may be more pronounced in children and deserve special attention. Ongoing efforts must focus on expanding and validating new biomarkers, innovative study design, and thorough monitoring of adverse events in children treated with CFTR modulators.
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Affiliation(s)
- Elizabeth L Kramer
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229
| | - John P Clancy
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229
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Doull I. Cystic Fibrosis Papers of the Year 2015. Paediatr Respir Rev 2016; 20 Suppl:18-20. [PMID: 27475293 DOI: 10.1016/j.prrv.2016.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Studies published in the last year have expanded our knowledge of potential disease modifying agents in the treatment of class II, III and IV CFTR mutations, and included the first report of an efficacious gene therapy for CF. There is also an important message on increasing use of conventional chronic therapies even in milder disease, and the pernicious effect of chronic infection on pulmonary function.
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Affiliation(s)
- Iolo Doull
- Department of Paediatric Respiratory Medicine and Paediatric, Cystic Fibrosis Centre, Children's Hospital for Wales, Cardiff, CF14 4XN, UK.
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