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Efremova A, Melyanovskaya Y, Krasnova M, Voronkova A, Mokrousova D, Zhekaite E, Bulatenko N, Makhnach O, Bukharova T, Kutsev S, Goldshtein D, Kondratyeva E. Estimation of Chloride Channel Residual Function and Assessment of Targeted Drugs Efficiency in the Presence of a Complex Allele [L467F;F508del] in the CFTR Gene. Int J Mol Sci 2024; 25:10424. [PMID: 39408749 PMCID: PMC11476812 DOI: 10.3390/ijms251910424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2024] [Revised: 09/23/2024] [Accepted: 09/24/2024] [Indexed: 10/20/2024] Open
Abstract
Complex alleles of the CFTR gene complicate the diagnosis of cystic fibrosis (CF), the classification of its pathogenic variants, affect the clinical picture of the disease and can affect the efficiency of targeted drugs. The total frequency of complex allele [L467F;F508del] in the Russian population of patients with CF is 0.74%, and in patients with the F508del/F508del genotype, its frequency reaches 8%. This article presents multi-faceted study of the complex allele [L467F;F508del] in a cohort of patients with genotypes [L467F;F508del]/class I (c.3532_3535dup, c.1766+2T>C, W1310X, 712-1G>T), and data for a unique patient with the genotype [L467F;F508del]/[L467F;F508del]. Using the intestinal current measurement method, it was demonstrated the absence of CFTR function for [L467F;F508del]/class I and [L467F;F508del]/[L467F;F508del] genotypes. In intestinal organoids, it was shown that [L467F;F508del] in combination with class I variants and in the homozygotes abolishes the efficacy of both two-component (ivacaftor+lumacaftor; ivacaftor+tezacaftor) and three-component (ivacaftor+tezacaftor+elexacaftor) targeted drugs. When prescribing ivacaftor+tezacaftor+elexacaftor to three patients, they did not have a clinical effect after 6-12 months.
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Affiliation(s)
- Anna Efremova
- Research Centre for Medical Genetics, Moskvorechye Str. 1, 115522 Moscow, Russia; (Y.M.); (M.K.); (A.V.); (D.M.); (E.Z.); (O.M.); (T.B.); (D.G.); (E.K.)
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2
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Yıldız CA, Selçuk Balcı M, Karabulut Ş, Başer ZM, Kalyoncu M, Metin Çakar N, Akkitap Yiğit MM, Baysal EE, Özdemircioğlu F, Uzunoğlu B, Taştan G, Ergenekon P, Gökdemir Y, Erdem Eralp E, Karakoç F, Ata P, Karadağ B. Exploring Turkey's mosaic of novel variants and complex alleles in cystic fibrosis genetics. Pediatr Pulmonol 2024. [PMID: 39291770 DOI: 10.1002/ppul.27249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2024] [Revised: 08/09/2024] [Accepted: 08/31/2024] [Indexed: 09/19/2024]
Abstract
BACKGROUNDS Genetic variants in CF transmembrane conductance regulator (CFTR) gene causes cystic fibrosis (CF), a prevalent autosomal recessive disorder. More than 2000 variants in CFTR have been described as disease causative. This study aims to delineate the genotypic and phenotypic landscape of CF among people with CF (pwCF) followed at the largest CF center in Turkey. METHODS We conducted a descriptive and retrospective analysis of 481 patients registered with the European CF Society Patient Registry and followed at Marmara University Selim Çöremen CF Center from 2015 onwards. Comprehensive CFTR analysis was utilized for genetic diagnosis. Besides the whole cohort, novel variants and complex alleles were also described. RESULTS Our cohort exhibited a broad spectrum of CFTR variants, with 136 different variants detected, indicating substantial genetic diversity. The F508del variant was less prevalent in our cohort compared to US and European averages, which could reflect unique genetic and demographic characteristics of the Turkish population. Additionally, we identified nine novel variants in 12 alleles, which enhances the understanding of CF's genetic complexity in this region, and complex alleles in 32 pwCF. CONCLUSION Our research underscores the heterogeneity of CFTR variants in Turkey and highlights the necessity for extensive genetic profiling particularly for diverse populations to provide effective personalized treatment strategies. It is crucial to understand the full spectrum of CFTR variants with the advent of CFTR modulators.
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Affiliation(s)
- Ceren Ayça Yıldız
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Merve Selçuk Balcı
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Şeyda Karabulut
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Zeynep Münteha Başer
- Department of Medical Genetics, Marmara University School of Medicine, Istanbul, Turkey
| | - Mine Kalyoncu
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Neval Metin Çakar
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | | | - Eda Esra Baysal
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Fulya Özdemircioğlu
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Burcu Uzunoğlu
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Gamze Taştan
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Pınar Ergenekon
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Yasemin Gökdemir
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Ela Erdem Eralp
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Fazilet Karakoç
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
| | - Pınar Ata
- Department of Medical Genetics, Marmara University School of Medicine, Istanbul, Turkey
| | - Bülent Karadağ
- Division of Pediatric Pulmonology, Marmara University School of Medicine, Istanbul, Turkey
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3
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De Paolis E, Tilocca B, Inchingolo R, Lombardi C, Perrucci A, Maneri G, Roncada P, Varone F, Luca R, Urbani A, Minucci A, Santonocito C. The novel CFTR haplotype E583G/F508del in CFTR-related disorder. Mol Biol Rep 2024; 51:849. [PMID: 39052151 PMCID: PMC11272816 DOI: 10.1007/s11033-024-09732-x] [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: 06/04/2024] [Accepted: 06/17/2024] [Indexed: 07/27/2024]
Abstract
BACKGROUND CFTR-related disorder (CFTR-RD) is a clinical entity associated to complex diagnostic paths and newly upgraded standard of care. In CFTR-RD, CFTR genotyping represents a diagnostic surrogate marker. In case of novel haplotype, the diagnosis could represents an area of concern. We described the molecular evaluation of the rare CFTR variant E583G identified in trans with the F508del in a novel haplotype. METHODS AND RESULTS An adult woman was referred to our pulmonary unit for persistent respiratory symptoms. CFTR Next Generation Sequencing was performed to evaluate full-gene mutational status. The variant identified was evaluated for its pathogenicity integrating clinical evidences with dedicated bioinformatics analyses. Clinical evaluation of patient matched with a mono-organ CFTR-RD diagnosis. Genotyping revealed the novel CFTR haplotype F508del/E583G. Multiple evidences of a deleterious effect of the CFTR E583G rare variant emerged from the bioinformatics analyses performed. CONCLUSIONS Guidelines for CFTR-RD are available with the purpose of harmonizing clinical and molecular investigations. In such context, the identification of novel CFTR haplotype need to a deeper evaluation with a combination of skills. The novel E583G variant could be considered of clinical interest and overall a CFTR-RD Variants of Varying Clinical Consequences.
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Affiliation(s)
- Elisa De Paolis
- Departmental Unit of Molecular and Genomic Diagnostics, Genomics Core Facility, Gemelli Science and Technology Park (G-STeP), Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, 00168, Italy
- Clinical Chemistry, Biochemistry and Molecular Biology Operations (UOC), Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Bruno Tilocca
- Department of Health Science, University "Magna Graecia" of Catanzaro, Catanzaro, 88100, Italy
| | - Riccardo Inchingolo
- Pulmonary Medicine Unit, Department of Medical and Surgical Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Carla Lombardi
- Clinical Chemistry, Biochemistry and Molecular Biology Operations (UOC), Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Alessia Perrucci
- Departmental Unit of Molecular and Genomic Diagnostics, Genomics Core Facility, Gemelli Science and Technology Park (G-STeP), Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, 00168, Italy
| | - Giulia Maneri
- Departmental Unit of Molecular and Genomic Diagnostics, Genomics Core Facility, Gemelli Science and Technology Park (G-STeP), Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, 00168, Italy
| | - Paola Roncada
- Department of Health Science, University "Magna Graecia" of Catanzaro, Catanzaro, 88100, Italy
| | - Francesco Varone
- Pulmonary Medicine Unit, Department of Medical and Surgical Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Richeldi Luca
- Pulmonary Medicine Unit, Department of Medical and Surgical Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
- Catholic University of Sacread Heart, Rome, 1-00168, Italy
| | - Andrea Urbani
- Clinical Chemistry, Biochemistry and Molecular Biology Operations (UOC), Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
- Department of Basic Biotechnological Sciences, Intensivological and Perioperative Clinics, Catholic University of Sacred Heart, Largo Agostino Gemelli,, Rome, 00168, Italy
| | - Angelo Minucci
- Departmental Unit of Molecular and Genomic Diagnostics, Genomics Core Facility, Gemelli Science and Technology Park (G-STeP), Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, 00168, Italy
| | - Concetta Santonocito
- Departmental Unit of Molecular and Genomic Diagnostics, Genomics Core Facility, Gemelli Science and Technology Park (G-STeP), Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, 00168, Italy.
- Clinical Chemistry, Biochemistry and Molecular Biology Operations (UOC), Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.
- Department of Basic Biotechnological Sciences, Intensivological and Perioperative Clinics, Catholic University of Sacred Heart, Largo Agostino Gemelli,, Rome, 00168, Italy.
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Krasnova M, Efremova A, Mokrousova D, Bukharova T, Kashirskaya N, Kutsev S, Kondratyeva E, Goldshtein D. Advances in the Study of Common and Rare CFTR Complex Alleles Using Intestinal Organoids. J Pers Med 2024; 14:129. [PMID: 38392563 PMCID: PMC10890655 DOI: 10.3390/jpm14020129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/15/2024] [Accepted: 01/19/2024] [Indexed: 02/24/2024] Open
Abstract
Complex alleles (CAs) arise when two or more nucleotide variants are present on a single allele. CAs of the CFTR gene complicate the cystic fibrosis diagnosis process, classification of pathogenic variants, and determination of the clinical picture of the disease and increase the need for additional studies to determine their pathogenicity and modulatory effect in response to targeted therapy. For several different populations around the world, characteristic CAs of the CFTR gene have been discovered, although in general the prevalence and pathogenicity of CAs have not been sufficiently studied. This review presents examples of using intestinal organoid models for assessments of the two most common and two rare CFTR CAs in individuals with cystic fibrosis in Russia.
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Affiliation(s)
- Maria Krasnova
- Research Centre for Medical Genetics, Moscow 115522, Russia
| | - Anna Efremova
- Research Centre for Medical Genetics, Moscow 115522, Russia
| | | | | | - Nataliya Kashirskaya
- Research Centre for Medical Genetics, Moscow 115522, Russia
- Moscow Regional Research and Clinical Institute ("MONIKI"), Schepkina Street, 61/2, 1, Moscow 129110, Russia
| | - Sergey Kutsev
- Research Centre for Medical Genetics, Moscow 115522, Russia
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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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Bear C, Ratjen F. Charting the path to expanded access for CFTR modulator drugs: the nose knows. Eur Respir J 2023; 62:2301387. [PMID: 37857432 DOI: 10.1183/13993003.01387-2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 10/21/2023]
Affiliation(s)
- Christine Bear
- Molecular Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Felix Ratjen
- Department of Physiology, University of Toronto, Toronto, ON, Canada
- Translational Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
- Division of Respiratory Medicine, Department of Pediatrics, Hospital for Sick Children, Toronto, ON, Canada
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7
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Blotas C, Férec C, Moisan S. Tissue-Specific Regulation of CFTR Gene Expression. Int J Mol Sci 2023; 24:10678. [PMID: 37445855 DOI: 10.3390/ijms241310678] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 07/15/2023] Open
Abstract
More than 2000 variations are described within the CFTR (Cystic Fibrosis Transmembrane Regulator) gene and related to large clinical issues from cystic fibrosis to mono-organ diseases. Although these CFTR-associated diseases have been well documented, a large phenotype spectrum is observed and correlations between phenotypes and genotypes are still not well established. To address this issue, we present several regulatory elements that can modulate CFTR gene expression in a tissue-specific manner. Among them, cis-regulatory elements act through chromatin loopings and take part in three-dimensional structured organization. With tissue-specific transcription factors, they form chromatin modules and can regulate gene expression. Alterations of specific regulations can impact and modulate disease expressions. Understanding all those mechanisms highlights the need to expand research outside the gene to enhance our knowledge.
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Affiliation(s)
- Clara Blotas
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France
| | - Claude Férec
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France
| | - Stéphanie Moisan
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, CHU Brest, F-29200 Brest, France
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8
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Kleinfelder K, Somenza E, Farinazzo A, Conti J, Lotti V, Latorre RV, Rodella L, Massella A, Tomba F, Bertini M, Sorio C, Melotti P. CFTR Modulators Rescue the Activity of CFTR in Colonoids Expressing the Complex Allele p.[R74W;V201M;D1270N]/dele22_24. Int J Mol Sci 2023; 24:ijms24065199. [PMID: 36982273 PMCID: PMC10048957 DOI: 10.3390/ijms24065199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/24/2023] [Accepted: 03/02/2023] [Indexed: 03/11/2023] Open
Abstract
An Italian, 46-year-old female patient carrying the complex allele p.[R74W;V201M;D1270N] in trans with CFTR dele22_24 was diagnosed at the Cystic Fibrosis (CF) Center of Verona as being affected by CF-pancreatic sufficient (CF-PS) in 2021. The variant V201M has unknown significance, while both of the other variants of this complex allele have variable clinical consequences, according to the CFTR2 database, with reported clinical benefits for treatment with ivacaftor + tezacaftor and ivacaftor + tezacaftor + elexacaftor in patients carrying the R74W-D1270N complex allele, which are currently approved (in USA, not yet in Italy). She was previously followed up by pneumologists in northern Italy because of frequent bronchitis, hemoptysis, recurrent rhinitis, Pseudomonas aeruginosa lung colonization, bronchiectasis/atelectasis, bronchial arterial embolization and moderately compromised lung function (FEV1: 62%). Following a sweat test with borderline results, she was referred to the Verona CF Center where she presented abnormal values in both optical beta-adrenergic sweat tests and intestinal current measurement (ICM). These results were consistent with a diagnosis of CF. CFTR function analyses were also performed in vitro by forskolin-induced swelling (FIS) assay and short-circuit currents (Isc) in the monolayers of the rectal organoids. Both of these assays showed significantly increased CFTR activity following treatment with the CFTR modulators. Western-blot analysis revealed increased fully glycosylated CFTR protein after treatment with correctors, in line with the functional analysis. Interestingly, tezacaftor, together with elexacaftor, rescued the total organoid area under steady-state conditions, even in the absence of the CFTR agonist forskolin. In conclusion, in ex vivo and in vitro assays, we measured a residual function that was significantly enhanced by in vitro incubation with CFTR modulators, especially by ivacaftor + tezacaftor + elexacaftor, suggesting this combination as a potentially optimal treatment for this case.
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Affiliation(s)
- Karina Kleinfelder
- Department of Medicine, Division of General Pathology, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
| | - Elena Somenza
- Department of Medicine, Division of General Pathology, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
| | - Alessia Farinazzo
- Department of Medicine, Division of General Pathology, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
| | - Jessica Conti
- Department of Medicine, Division of General Pathology, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
| | - Virginia Lotti
- Department of Medicine, Division of General Pathology, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
| | - Roberta Valeria Latorre
- Department of Medicine, Division of General Pathology, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
| | - Luca Rodella
- Endoscopic Surgery Unit, Azienda Ospedaliera Universitaria Integrata Verona, 37126 Verona, Italy
| | - Arianna Massella
- Endoscopic Surgery Unit, Azienda Ospedaliera Universitaria Integrata Verona, 37126 Verona, Italy
| | - Francesco Tomba
- Endoscopic Surgery Unit, Azienda Ospedaliera Universitaria Integrata Verona, 37126 Verona, Italy
| | - Marina Bertini
- Cystic Fibrosis Centre, Azienda Ospedaliera Universitaria Integrata Verona, Piazzale Stefani, 1, 37126 Verona, Italy
| | - Claudio Sorio
- Department of Medicine, Division of General Pathology, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
- Correspondence: (C.S.); (P.M.)
| | - Paola Melotti
- Cystic Fibrosis Centre, Azienda Ospedaliera Universitaria Integrata Verona, Piazzale Stefani, 1, 37126 Verona, Italy
- Correspondence: (C.S.); (P.M.)
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9
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Lal D, Brar T, Ramkumar SP, Li J, Kato A, Zhang L. Genetics and epigenetics of chronic rhinosinusitis. J Allergy Clin Immunol 2023; 151:848-868. [PMID: 36797169 DOI: 10.1016/j.jaci.2023.01.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 01/04/2023] [Accepted: 01/06/2023] [Indexed: 02/16/2023]
Abstract
Discerning the genetics and epigenetics of chronic rhinosinusitis (CRS) may optimize outcomes through early diagnostics, personalized and novel therapeutics, and early prognostication. CRS associated with cystic fibrosis and primary ciliary dyskinesia has well-characterized genetic mutations. Most CRS subjects, however, do not exhibit identifiable monogenic alterations. Clustering in related individuals is seen in CRS with nasal polyps. Spouses of subjects with CRS without nasal polyps also may be at increased risk of the same disease. These observations generate questions on genetic and environmental influences in CRS. Genome-wide association studies have identified variations and polymorphisms between CRS and control subjects in genes related to innate and adaptive immunity. Candidate gene and transcriptomics studies have investigated and identified genetic variations related to immunity, inflammation, epithelial barrier function, stress-response, antigen processing, T-cell regulation, and cytokines in CRS. Epigenetic studies have identified mechanisms through which environmental factors may affect these gene functions. However, causality is not determined for most variations. Inferences drawn from these data must be measured because most investigations report unreplicated results from small study populations. Large, replicated studies in tight cohorts across diverse populations remain a pressing need in studying CRS genetics.
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Affiliation(s)
- Devyani Lal
- Department of Otolaryngology Head and Neck Surgery, Mayo Clinic in Arizona, Phoenix, Ariz.
| | - Tripti Brar
- Department of Otolaryngology Head and Neck Surgery, Mayo Clinic in Arizona, Phoenix, Ariz
| | - Shreya Pusapadi Ramkumar
- Department of Otolaryngology Head and Neck Surgery, Mayo Clinic in Arizona, Phoenix, Ariz; Saint Louis University School of Medicine, St Louis, Mo
| | - Jingyun Li
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China; Beijing Tongren Hospital, Capital Medical University, Beijing, China; Department of Allergy, Beijing Tongren Hospital, Capital Medical University, Beijing, China; Beijing Laboratory of Allergic Diseases and Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, China; Research Unit of Diagnosis and Treatment of Chronic Nasal Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Atsushi Kato
- Division of Allergy and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Ill
| | - Luo Zhang
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China; Beijing Tongren Hospital, Capital Medical University, Beijing, China; Department of Allergy, Beijing Tongren Hospital, Capital Medical University, Beijing, China; Beijing Laboratory of Allergic Diseases and Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, China; Research Unit of Diagnosis and Treatment of Chronic Nasal Diseases, Chinese Academy of Medical Sciences, Beijing, China
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10
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Abstract
Cystic fibrosis (CF) is a multiorgan disease caused by a wide variety of mutations in the cystic fibrosis transmembrane conductance regulator gene. As treatment has progressed from symptom mitigation to targeting of specific molecular defects, genetics has played an important role in identifying the proper precision therapies for each individual. Novel therapeutic approaches are focused on expanding treatment to a greater number of individuals as well as working toward a cure. This review discusses the role of genetics in our understanding of CF with a particular emphasis on how genetics informs the exciting landscape of current and novel CF therapies.
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Affiliation(s)
- Anya T Joynt
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Garry R Cutting
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Neeraj Sharma
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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11
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Personalized Selection of a CFTR Modulator for a Patient with a Complex Allele [L467F;F508del]. Curr Issues Mol Biol 2022; 44:5126-5138. [PMID: 36286063 PMCID: PMC9600521 DOI: 10.3390/cimb44100349] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/16/2022] [Accepted: 10/18/2022] [Indexed: 11/17/2022] Open
Abstract
The presence of complex alleles in the CFTR gene can lead to difficulties in diagnosing cystic fibrosis and cause resistance to therapy with CFTR modulators. Tezacaftor/ivacaftor therapy for 8 months in a patient with the initially established F508del/F508del genotype did not lead to an improvement in her condition—there was no change in spirometry and an increase in the patient’s weight, while there was only a slight decrease in NaCl values, measured by a sweat test. The intestinal current measurements of the patient’s rectal biopsy showed no positive dynamics in the rescue of CFTR function while taking tezacaftor/ivacaftor. The assumption that the patient had an additional mutation in the cis position was confirmed by sequencing the CFTR gene, and the complex allele [L467F;F508del] was identified. Based on the rescue of CFTR function by elexacaftor/tezacaftor/ivacaftor obtained using forskolin-induced swelling on intestinal organoids, the patient was prescribed therapy with this targeted drug. The use of elexacaftor/tezacaftor/ivacaftor for 7 months resulted in a significant improvement in the patient’s clinical condition.
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12
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Evaluation of the Complex p.[Leu467Phe;Phe508del] CFTR Allele in the Intestinal Organoids Model: Implications for Therapy. Int J Mol Sci 2022; 23:ijms231810377. [PMID: 36142302 PMCID: PMC9499621 DOI: 10.3390/ijms231810377] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/03/2022] [Accepted: 09/06/2022] [Indexed: 11/18/2022] Open
Abstract
In the cohort of Russian patients with cystic fibrosis, the p.[Leu467Phe;Phe508del] complex allele (legacy name [L467F;F508del]) of the CFTR gene is understudied. In this research, we present the results of frequency evaluation of the [L467F;F508del] complex allele in the Russian Federation among patients with a F508del/F508del genotype, its effect on the clinical course of cystic fibrosis, the intestinal epithelium ionic channel function, and the effectiveness of target therapy. The frequency of the [L467F;F508del] complex allele among patients with homozygous F508del was determined with multiplex ligase-dependent probe amplification followed by polymerase chain reaction and fragment analysis. The function of ionic channels, including the residual CFTR function, and the effectiveness of CFTR modulators was analyzed using intestinal current measurements on rectal biopsy samples and the forskolin-induced swelling assay on organoids. The results showed that the F508del/[L467F;F508del] genotype is present in 8.2% of all Russian patients with F508del in a homozygous state. The clinical course of the disease in patients with the F508del/[L467F;F508del] genotype is severe and does not vary from the course in the cohort with homozygous F508del, although the CFTR channel function is significantly lower. For patients with the F508del/[L467F;F508del] genotype, we can recommend targeted therapy using a combined ivacaftor + tezacaftor + elexacaftor medication.
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Terlizzi V, Centrone C, Ferrari B, Castellani C, Gunawardena TNA, Taccetti G, Laselva O. Modulator Therapy in Cystic Fibrosis Patients with cis Variants in F508del Complex Allele: A Short-Term Observational Case Series. J Pers Med 2022; 12:jpm12091421. [PMID: 36143206 PMCID: PMC9504164 DOI: 10.3390/jpm12091421] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 11/16/2022] Open
Abstract
Previous studies reported the influence of cis variants in F508del cystic fibrosis (CF) patients in their responses to CFTR modulators. The current study is a prospective, observational study involving three patients with CF and pancreatic insufficiency, carrying a complex allele including F508del with A238V, I1027T, or L467F. We report clinical data before and after 4 weeks of treatment with tezacaftor (TEZ)/ivacaftor (IVA), elexacaftor (ELX)/TEZ/IVA, and lumacaftor (LUM)/IVA for patients with complex alleles A238V, I1027T, and L467F, respectively. The 50-year-old patient bearing F508del;A238V/D1152H showed a normal sweat test (13 mEq/L) and improvements in forced expiratory volume in the first second (FEV1) (+7 points), body mass index (BMI) (+0.85), and respiratory CF Questionnaire-Revised (CFQ-R) domain (+22.2 points). The 12-year-old patient bearing F508del;I1027T/R709X showed an improvement in a sweat test (−40 mEq/l), FEV1 (+9 points) and the respiratory CFQ-R domain (+16.7 points). No changes in outcomes were observed for the 6-year-old patient F508del;L467F/F508del. Our data highlight that the reported variants do not modify the phenotypic expression of F508del. Searching L467F is crucial in CF patients with F508del nonresponsive to ELX/TEZ/IVA. Further data are needed to evaluate the clinical effect of these variants after a longer follow up.
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Affiliation(s)
- Vito Terlizzi
- Department of Paediatric Medicine, Cystic Fibrosis Regional Reference Center, Meyer Children’s Hospital, 50139 Florence, Italy
- Correspondence: (V.T.); (O.L.); Tel.: +39-0881588074 (O.L.)
| | - Claudia Centrone
- Diagnostic Genetics Unit, Careggi University Hospital, 50134 Florence, Italy
| | - Beatrice Ferrari
- Rehabilitation Unit, Meyer Children’s Hospital, 50139 Florence, Italy
| | - Chiara Castellani
- Department of Radiology, Meyer Children’s Hospital, 50139 Florence, Italy
| | - Tarini N. A. Gunawardena
- Programme in Molecular Medicine, The Hospital for Sick Children, Toronto, ON M5G 8X4, Canada
- Programme in Translational Medicine, The Hospital for Sick Children, Toronto, ON M5G 8X4, Canada
| | - Giovanni Taccetti
- Department of Paediatric Medicine, Cystic Fibrosis Regional Reference Center, Meyer Children’s Hospital, 50139 Florence, Italy
| | - Onofrio Laselva
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy
- Correspondence: (V.T.); (O.L.); Tel.: +39-0881588074 (O.L.)
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14
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Cuyx S, Ramalho SS, Callebaut I, Cuppens H, Kmit A, Arnauts K, Ferrante M, Verfaillie C, Ensinck M, Carlon MS, Boon M, Proesmans M, Dupont L, De Boeck K, Farinha CM, Vermeulen F, Ramalho AS. Severity of the S1251N allele in cystic fibrosis is affected by the presence of the F508C variant in cis. J Cyst Fibros 2022; 21:644-651. [PMID: 35690578 DOI: 10.1016/j.jcf.2022.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 04/25/2022] [Accepted: 05/30/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND In cystic fibrosis (CF), genotype-phenotype correlation is complicated by the large number of CFTR variants, the influence of modifier genes, environmental effects, and the existence of complex alleles. We document the importance of complex alleles, in particular the F508C variant present in cis with the S1251N disease-causing variant, by detailed analysis of a patient with CF, with the [S1251N;F508]/G542X genotype and a very mild phenotype, contrasting it to that of four subjects with the [S1251N;F508C]/F508del genotype and classical CF presentation. METHODS Genetic differences were identified by Sanger sequencing and CFTR function was quantified using rectal organoids in rectal organoid morphology analysis (ROMA) and forskolin-induced swelling (FIS) assays. CFTR variants were further characterised in CF bronchial epithelial (CFBE) cell lines. The impact of involved amino acid changes in the CFTR 3D protein structure was evaluated. RESULTS Organoids of the patient [S1251N;F508] with mild CF phenotype confirmed the CF diagnosis but showed higher residual CFTR function compared to the four others [S1251N;F508C]. CFBE cell lines showed a decrease in [S1251N;F508C]-CFTR function but not in processing when compared to [S1251N;F508]-CFTR. Analysis of the 3D CFTR structure suggested an additive deleterious effect of the combined presence of S1251N and F508C with respect to NBD1-2 dimerisation. CONCLUSIONS In vitro and in silico data show that the presence of F508C in cis with S1251N decreases CFTR function without affecting processing. Complex CFTR alleles play a role in clinical phenotype and their identification is relevant in the context of personalised medicine for each patient with CF.
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Affiliation(s)
- Senne Cuyx
- KU Leuven, Department of Development and Regeneration, Woman and Child Unit, CF research lab, B-3000 Leuven, Belgium; University Hospital Leuven, Department of Pediatrics, Pediatric Pulmonology, B-3000 Leuven, Belgium
| | - Sofia S Ramalho
- University of Lisboa, BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
| | - Isabelle Callebaut
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, F-75005 Paris, France
| | | | - Arthur Kmit
- University of Lisboa, BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
| | - Kaline Arnauts
- Department of Chronic Diseases, Metabolism and Ageing (CHROMETA), Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, Leuven, Belgium; KU Leuven, Department of Development and Regeneration, Stem Cell Institute Leuven (SCIL), B-3000 Leuven, Belgium
| | - Marc Ferrante
- Department of Chronic Diseases, Metabolism and Ageing (CHROMETA), Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, Leuven, Belgium; KU Leuven, Department of Gastroenterology and Hepatology, University Hospital Leuven, B-3000 Leuven, Belgium
| | - Catherine Verfaillie
- KU Leuven, Department of Development and Regeneration, Stem Cell Institute Leuven (SCIL), B-3000 Leuven, Belgium
| | - Marjolein Ensinck
- Laboratory for Molecular Virology and Drug Discovery, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, 3000, Belgium; KU Leuven, Department of Chronic Diseases, Metabolism and Ageing; BREATHE, B-3000 Leuven, Belgium
| | - Marianne S Carlon
- Laboratory for Molecular Virology and Drug Discovery, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, 3000, Belgium; KU Leuven, Department of Chronic Diseases, Metabolism and Ageing; BREATHE, B-3000 Leuven, Belgium
| | - Mieke Boon
- KU Leuven, Department of Development and Regeneration, Woman and Child Unit, CF research lab, B-3000 Leuven, Belgium; University Hospital Leuven, Department of Pediatrics, Pediatric Pulmonology, B-3000 Leuven, Belgium
| | - Marijke Proesmans
- KU Leuven, Department of Development and Regeneration, Woman and Child Unit, CF research lab, B-3000 Leuven, Belgium; University Hospital Leuven, Department of Pediatrics, Pediatric Pulmonology, B-3000 Leuven, Belgium
| | - Lieven Dupont
- KU Leuven, Department of Chronic Diseases, Metabolism and Ageing; BREATHE, B-3000 Leuven, Belgium; University Hospital Leuven, Department of Respiratory Diseases, B-3000 Leuven, Belgium
| | - Kris De Boeck
- KU Leuven, Department of Development and Regeneration, Woman and Child Unit, CF research lab, B-3000 Leuven, Belgium; University Hospital Leuven, Department of Pediatrics, Pediatric Pulmonology, B-3000 Leuven, Belgium
| | - Carlos M Farinha
- University of Lisboa, BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
| | - François Vermeulen
- KU Leuven, Department of Development and Regeneration, Woman and Child Unit, CF research lab, B-3000 Leuven, Belgium; University Hospital Leuven, Department of Pediatrics, Pediatric Pulmonology, B-3000 Leuven, Belgium
| | - Anabela S Ramalho
- KU Leuven, Department of Development and Regeneration, Woman and Child Unit, CF research lab, B-3000 Leuven, Belgium
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Persico I, Feresin A, Faleschini M, Fontana G, Sirchia F, Faletra F, La Bianca M, Suergiu S, Morgutti M, Maschio M, D'Adamo AP, Raraigh KS, Savoia A, Bottega R. Things come in threes: A new complex allele and a novel deletion within the CFTR gene complicate an accurate diagnosis of cystic fibrosis. Mol Genet Genomic Med 2022; 10:e1926. [PMID: 35348309 PMCID: PMC9184661 DOI: 10.1002/mgg3.1926] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 02/16/2022] [Accepted: 03/08/2022] [Indexed: 11/07/2022] Open
Abstract
Background Despite consolidated guidelines, the clinical diagnosis and prognosis of cystic fibrosis (CF) is still challenging mainly because of the extensive phenotypic heterogeneity and the high number of CFTR variants, including their combinations as complex alleles. Results We report a family with a complicated syndromic phenotype, which led to the suspicion not only of CF, but of a dominantly inherited skeletal dysplasia (SD). Whereas the molecular basis of the SD was not clarified, segregation analysis was central to make a correct molecular diagnosis of CF, as it allowed to identify three CFTR variants encompassing two known maternal mutations and a novel paternal microdeletion. Conclusion This case well illustrates possible pitfalls in the clinical and molecular diagnosis of CF; presence of complex phenotypes deflecting clinicians from appropriate CF recognition, and/or identification of two mutations assumed to be in trans but with an unconfirmed status, which underline the importance of an in‐depth molecular CFTR analysis.
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Affiliation(s)
- Ilaria Persico
- Department of Medical Sciences, University of Trieste, Trieste, Italy
| | - Agnese Feresin
- Department of Medical Sciences, University of Trieste, Trieste, Italy
| | - Michela Faleschini
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - Giorgia Fontana
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - Fabio Sirchia
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - Flavio Faletra
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - Martina La Bianca
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - Sarah Suergiu
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - Marcello Morgutti
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - Massimo Maschio
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - Adamo Pio D'Adamo
- Department of Medical Sciences, University of Trieste, Trieste, Italy
| | - Karen S Raraigh
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Anna Savoia
- Department of Medical Sciences, University of Trieste, Trieste, Italy.,Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - Roberta Bottega
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
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Aspinall SA, Mackintosh KA, Hill DM, Cope B, McNarry MA. Evaluating the Effect of Kaftrio on Perspectives of Health and Wellbeing in Individuals with Cystic Fibrosis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19106114. [PMID: 35627651 PMCID: PMC9141876 DOI: 10.3390/ijerph19106114] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/09/2022] [Accepted: 05/11/2022] [Indexed: 11/16/2022]
Abstract
Background: Modulator therapy represents a significant step forward in CF care and is expected to have a significant impact on the health and mortality of many individuals with CF. Studies have predominantly explored the physiological effects of modulator therapy on clinical outcomes, with little consideration of the individual lived experience of modulator therapy among adults with Cystic Fibrosis. Methods: To explore this, semi-structured interviews were conducted with 12 individuals currently taking Kaftrio, which were subsequently thematically analysed. Results: Three overarching themes were identified: (i) positive perception of Kaftrio, (ii) negative perception of Kaftrio, and (iii) the relationships with the clinical team. The experience of modulator therapy should be recognised as being unique to the individual, with perceptions of illness, self-identity, and outcomes strongly dictating the lived experience. Conclusions: There is a consensus that, while for many, the quality of life is evidently increased through the use of Kaftrio, this is not without its own challenges. This highlights the need for both individuals with CF and their clinical teams to learn to navigate this new disease landscape.
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17
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Petrova NV, Kashirskaya NY, Vasilyeva TA, Balinova NV, Marakhonov AV, Kondratyeva EI, Zhekaite EK, Voronkova AY, Kutsev SI, Zinchenko RA. High frequency of complex CFTR alleles associated with c.1521_1523delCTT (F508del) in Russian cystic fibrosis patients. BMC Genomics 2022; 23:252. [PMID: 35365085 PMCID: PMC8973895 DOI: 10.1186/s12864-022-08466-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 03/08/2022] [Indexed: 11/16/2022] Open
Abstract
Cystic fibrosis (CF, MIM# 219,700) is an autosomal recessive disease caused by pathogenic variants within the CFTR gene. It was shown that genetic variants located in cis can affect disease severity or treatment response because of additive or epistatic effects. Studies on the prevalence of complex alleles in Russian CF patients have just begun. Aim To evaluate frequencies and genetic background of complex alleles carrying c.1521_1523delCTT (F508del) and c.1399C>T (L467F), c.2562T>G (T854=) or c.4389G>A (Q1463=) in cis; to determine clinical consequences of complex allele c.[1399C>T;1521_1523delCTT] ([L467;F508del]) in Russian CF patients. Methods Sequencing of coding regions of CFTR gene and analysis of polymorphic markers in CF patients carrying F508del variant. Comparing of clinical features in two groups patients having genotypes [L467F;F508del];[F508del] (group 1) and [F508del];[F508del] (group 2). Results Frequency of [L467F;F508del] allele linked to 2–2–21–6–17–13 haplotype was 4.42%, of [F508del;T854=;Q1463=] allele linked to haplotype 1–2–21–6–17–13 – 2.2% in F508del chromosomes. No differences in disease severity in patients carrying complex allele [L467F;F508del] and patients homozygous for F508del was found. Conclusion The frequency of complex alleles associated with F508del was at least 6.6% in Russian CF patients, which should be taken into account for the decision on optimal treatment options with CFTR modulators.
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Affiliation(s)
- Nika V Petrova
- Research Centre for Medical Genetics, Moscow, Russian Federation
| | | | | | | | - Andrey V Marakhonov
- Research Centre for Medical Genetics, Moscow, Russian Federation. .,Laboratory of Genetic Epidemiology, Research Centre for Medical Genetics, Moskvorechie St., 1, 115522, Moscow, Russian Federation.
| | | | - Elena K Zhekaite
- Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Anna Y Voronkova
- Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Sergey I Kutsev
- Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Rena A Zinchenko
- Research Centre for Medical Genetics, Moscow, Russian Federation.,N.A. Semashko National Research Institute of Public Health, Moscow, Russian Federation
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18
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The L467F-F508del Complex Allele Hampers Pharmacological Rescue of Mutant CFTR by Elexacaftor/Tezacaftor/Ivacaftor in Cystic Fibrosis Patients: The Value of the Ex Vivo Nasal Epithelial Model to Address Non-Responders to CFTR-Modulating Drugs. Int J Mol Sci 2022; 23:ijms23063175. [PMID: 35328596 PMCID: PMC8952007 DOI: 10.3390/ijms23063175] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 03/10/2022] [Accepted: 03/14/2022] [Indexed: 12/16/2022] Open
Abstract
Loss-of-function mutations of the CFTR gene cause cystic fibrosis (CF) through a variety of molecular mechanisms involving altered expression, trafficking, and/or activity of the CFTR chloride channel. The most frequent mutation among CF patients, F508del, causes multiple defects that can be, however, overcome by a combination of three pharmacological agents that improve CFTR channel trafficking and gating, namely, elexacaftor, tezacaftor, and ivacaftor. This study was prompted by the evidence of two CF patients, compound heterozygous for F508del and a minimal function variant, who failed to obtain any beneficial effects following treatment with the triple drug combination. Functional studies on nasal epithelia generated in vitro from these patients confirmed the lack of response to pharmacological treatment. Molecular characterization highlighted the presence of an additional amino acid substitution, L467F, in cis with the F508del variant, demonstrating that both patients were carriers of a complex allele. Functional and biochemical assays in heterologous expression systems demonstrated that the double mutant L467F-F508del has a severely reduced activity, with negligible rescue by CFTR modulators. While further studies are needed to investigate the actual prevalence of the L467F-F508del allele, our results suggest that this complex allele should be taken into consideration as plausible cause in CF patients not responding to CFTR modulators.
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19
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Raraigh KS, Aksit MA, Hetrick K, Pace RG, Ling H, O'Neal W, Blue E, Zhou YH, Bamshad MJ, Blackman SM, Gibson RL, Knowles MR, Cutting GR. Complete CFTR gene sequencing in 5,058 individuals with cystic fibrosis informs variant-specific treatment. J Cyst Fibros 2021; 21:463-470. [PMID: 34782259 DOI: 10.1016/j.jcf.2021.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 10/27/2021] [Accepted: 10/29/2021] [Indexed: 01/28/2023]
Abstract
BACKGROUND Cystic fibrosis (CF) is a recessive condition caused by variants in each CF transmembrane conductance regulator (CFTR) allele. Clinically affected individuals without two identified causal variants typically have no further interrogation of CFTR beyond examination of coding regions, but the development of variant-specific CFTR-targeted treatments necessitates complete understanding of CFTR genotype. METHODS Whole genome sequences were analyzed on 5,058 individuals with CF. We focused on the full CFTR gene sequence and identified disease-causing variants in three phases: screening for known and structural variants; discovery of novel loss-of-function variants; and investigation of remaining variants. RESULTS All variants identified in the first two phases and coding region variants found in the third phase were interpreted according to CFTR2 or ACMG criteria (n = 371; 16 [4.3%] previously unreported). Full gene sequencing enabled delineation of 18 structural variants (large insertions or deletions), of which two were novel. Additional CFTR variants of uncertain effect were found in 76 F508del homozygotes and in 21 individuals with other combinations of CF-causing variants. Both causative variants were identified in 98.1% (n = 4,960) of subjects, an increase of 2.3 percentage points from the 95.8% (n = 4,847) who had a registry- or chart-reported disease-causing CFTR genotype. Of the remaining 98 individuals, 78 carried one variant that has been associated with CF (CF-causing [n = 70] or resulting in varying clinical consequences n = 8]). CONCLUSIONS Complete CFTR gene sequencing in 5,058 individuals with CF identified at least one DNA variant in 99.6% of the cohort that is targetable by current molecular or emerging gene-based therapeutic technologies.
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Affiliation(s)
- Karen S Raraigh
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Melis A Aksit
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Kurt Hetrick
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Rhonda G Pace
- Marsico Lung Institute/UNC CF Research Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Hua Ling
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Wanda O'Neal
- Marsico Lung Institute/UNC CF Research Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Elizabeth Blue
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, United States
| | - Yi-Hui Zhou
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, United States
| | - Michael J Bamshad
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, United States; Department of Pediatrics, University of Washington, Seattle, WA 98195, United States; Brotman-Baty Institute, Seattle, WA 98195, United States
| | - Scott M Blackman
- Division of Pediatric Endocrinology and Diabetes, Johns Hopkins University, Baltimore, MD 21287, United States
| | - Ronald L Gibson
- Department of Pediatrics, University of Washington, Seattle, WA 98195, United States
| | - Michael R Knowles
- Marsico Lung Institute/UNC CF Research Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Garry R Cutting
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States.
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20
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Shteinberg M, Haq IJ, Polineni D, Davies JC. Cystic fibrosis. Lancet 2021; 397:2195-2211. [PMID: 34090606 DOI: 10.1016/s0140-6736(20)32542-3] [Citation(s) in RCA: 327] [Impact Index Per Article: 109.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/03/2020] [Accepted: 11/20/2020] [Indexed: 12/11/2022]
Abstract
Cystic fibrosis is a monogenic disease considered to affect at least 100 000 people worldwide. Mutations in CFTR, the gene encoding the epithelial ion channel that normally transports chloride and bicarbonate, lead to impaired mucus hydration and clearance. Classical cystic fibrosis is thus characterised by chronic pulmonary infection and inflammation, pancreatic exocrine insufficiency, male infertility, and might include several comorbidities such as cystic fibrosis-related diabetes or cystic fibrosis liver disease. This autosomal recessive disease is diagnosed in many regions following newborn screening, whereas in other regions, diagnosis is based on a group of recognised multiorgan clinical manifestations, raised sweat chloride concentrations, or CFTR mutations. Disease that is less easily diagnosed, and in some cases affecting only one organ, can be seen in the context of gene variants leading to residual protein function. Management strategies, including augmenting mucociliary clearance and aggressively treating infections, have gradually improved life expectancy for people with cystic fibrosis. However, restoration of CFTR function via new small molecule modulator drugs is transforming the disease for many patients. Clinical trial pipelines are actively exploring many other approaches, which will be increasingly needed as survival improves and as the population of adults with cystic fibrosis increases. Here, we present the current understanding of CFTR mutations, protein function, and disease pathophysiology, consider strengths and limitations of current management strategies, and look to the future of multidisciplinary care for those with cystic fibrosis.
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Affiliation(s)
- Michal Shteinberg
- Pulmonology Institute and CF Center, Carmel Medical Center, Haifa, Israel; Rappaport Faculty of Medicine, The Technion-Israel Institute of Technology, Haifa, Israel
| | - Iram J Haq
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK; Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | | | - Jane C Davies
- National Heart and Lung Institute, Imperial College London, London, UK; Royal Brompton and Harefield, Guy's and St Thomas' NHS Foundation Trust, London, UK.
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21
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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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Cuevas-Ocaña S, Laselva O, Avolio J, Nenna R. The era of CFTR modulators: improvements made and remaining challenges. Breathe (Sheff) 2020; 16:200016. [PMID: 33304402 PMCID: PMC7714553 DOI: 10.1183/20734735.0016-2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The entry into the clinic of CFTR modulators such as TRIKAFTA has significantly improved life for ∼90% CF patients carrying one or two F508del mutations but challenges remain for rare CFTR mutations and the management of lung infections @SaraOcana1 https://bit.ly/3aRafQF.
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Affiliation(s)
- Sara Cuevas-Ocaña
- Wolfson Centre for Stem Cells, Tissue Engineering and Modelling, School of Medicine, University of Nottingham Biodiscovery Institute, Nottingham, UK
| | - Onofrio Laselva
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Canada
- Dept of Physiology, University of Toronto, Toronto, Canada
| | - Julie Avolio
- Program in Translational Medicine, SickKids Research Institute, The Hospital for Sick Children, Toronto, Canada
| | - Raffaella Nenna
- Dept of Paediatrics, “Sapienza” University of Rome, Rome, Italy
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Callebaut I, Mense M, Farinha CM. Exploring the basic mechanisms in Cystic Fibrosis: Promoting data presentation and discussion at the 16th ECFS Basic Science Conference. J Cyst Fibros 2020; 19 Suppl 1:S1-S4. [PMID: 31932104 DOI: 10.1016/j.jcf.2019.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The revolution in cystic fibrosis treatment is rooted in tremendous interdisciplinary research efforts, which led in recent years to significant progress in precision medicine. Since 2004, a key annual event for the CF research community is the ECFS Basic Science Conference (BSC), which is an ideal venue for deep discussions around topical subjects and fosters basic CF-related research in Europe and beyond. This special issue explores topics that were featured at the 16th ECFS BSC, held in Dubrovnik in March 2019 and provides an overview of recent progress in various fields for understanding disease mechanisms, developing relevant cell and animal models and designing breakthrough therapies. The special issue also identifies a number of the key issues and challenges in the future development of transformative therapies for all patients with CF.
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Affiliation(s)
- Isabelle Callebaut
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005 Paris, France.
| | - Martin Mense
- Cystic Fibrosis Foundation, CFFT Lab, 44 Hartwell Ave., Lexington, MA 02421, USA
| | - Carlos M Farinha
- Biosystems and Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, Campo Grande 1749-016, Lisboa, Portugal
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