Reliability of the search for 19 common mutations in the CFTR gene in Russian cystic fibrosis patients and the calculated frequency of the disease in Russian Federation

В статье впервые представляется клинико-генетическая характеристика мутации c.1083G>A (p.Trp361*) в гене CFTR. Патогенный генетический вариант c.1083G>A (p.Trp361*) гена CFTR относится к нонсенс-мутациям (I класс) и впервые был внесён в базу данных CFTR1 (http://www.genet.sickkids.on.ca) в середине 2019 г. без описания клинической картины муковисцидоза. Методы. Проведен анализ амбулаторных карт и историй болезни двух пациентов из неродственных семей с редким генетическим вариантом c.1083G>A (p.Trp361*). Для определения разности кишечных потенциалов (ОРКП) и проведения форсколинового теста на кишечных органоидах использовали биопсийный материал слизистой прямой кишки пациентов. ДНК для секвенирования выделяли из лейкоцитов венозной крови пациентов. Результаты. Анализ клинических проявлений заболевания у детей 6 и 9 лет показал наличие хронической панкреатической недостаточности, более выраженной у одного ребенка с синдромом дистальной интестинальной обструкции кишечника в анамнезе. Клиническая картина второго пациента характеризовалась развитием в раннем возрасте транзиторной гипербилирубинемии, синдрома псевдо-Барттера, а в дальнейшем - повторными эпизодами бронхиальной обструкции и развитием полипозного риносинусита. ОРКП и форсколиновый тест на кишечных органоидах показали, что генетический вариант c.1083G>A (p.Trp361*) относится к вариантам гена CFTR с отсутствием функции хлорного канала. Выводы. Впервые представлены описание клинической картины муковисцидоза у двух пациентов из неродственных семей с патогенным вариантом c.1083G>A (p.Trp361*) в компаунде с вариантом c.1521_1523delCTT (p.Phe508del) (ранее называемом F508del) и результаты оценки функции белка CFTR методом ОРКП и форсколиновым тестом на кишечных органоидах. In this article we continue to describe the pathogenic variants of the CFTR gene identified among Russian cystic fibrosis (CF) patients. For the first time the clinical and genetic characteristics of the mutation c.1083G> A (p.Trp361 *) are presented. The pathogenic genetic variant c.1083G> A (p.Trp361 *) of the CFTR gene belongs to the nonsense mutations (class I) and was listed for the first time in the CFTR1 database (http://www.genet.sickkids.on.ca) by Professor Milan Macek et al. in mid-2019 without any description of clinical manifestations of cystic fibrosis. Methods. The data of the National Register of Patients with Cystic Fibrosis of the Russian Federation 2017 were analyzed. Outpatient records and case histories of two patients from unrelated families carrying a rare genetic variant c.1083G> A (p.Trp361 *) were analyzed. To determine the Intestinal current measurement (ICM) and Forskolin-induced swelling (FIS) in intestinal organoids, rectal biopsy material of CF patients was used. DNA for sequencing was isolated from leukocytes of venous blood of the patients. Results. Variant c.1083G> A (p.Trp361 *) was found in two patients from unrelated families from different regions of the Russian Federation, according to the Register of Cystic Fibrosis Patients in the Russian Federation 2017. Analysis of clinical manifestations of the disease in children 6 and 9 years old showed the presence of chronic pancreatic insufficiency, more expressed in one child with a history of distal intestinal obstruction syndrome. The clinical manifestation of the second patient was characterized by the development of transient hyperbilirubinemia, Pseudo-Bartter’s syndrome at an early age, and subsequently repeated episodes of bronchial obstruction and the development of polypoid rhinosinusitis. The ICM method and the FIS in intestinal organoids showed that the genetic variant c.1083G> A (p.Trp361 *) refers to the variants of the CFTR gene with the absence of chlorine channel function. Conclusion. The clinical picture of cystic fibrosis in two patients from unrelated families with the pathogenic variant c.1083G> A (p.Trp361 *) in the compound with variant c.1521_1523delCTT (p.Phe508del) (variant legacy name F508del) and results of the evaluation of the CFTR protein functions, obtained by the method of ICM and using the FIS assay in intestinal organoids, are presented for the first time. Patients continue to be under the control in Russian CF centers.

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Variety of large rearrangements in the CFTR gene in Russian patients with Cystic Fibrosis

Nauchno-prakticheskii zhurnal «Medicinskaia genetika» ◽

10.25557/2073-7998.2020.02.28-34 ◽

2020 ◽

pp. 28-34

Author(s):

Е.И. Кондратьева ◽

Н.В. Петрова ◽

А.Ю. Воронкова ◽

С.А. Красовский ◽

Е.Л. Амелина ◽

...

Keyword(s):

Cystic Fibrosis ◽

Russian Federation ◽

Genetic Variants ◽

Genetic Variant ◽

Cftr Gene ◽

Pathogenic Variants ◽

The Russian Federation ◽

Basic Characteristics ◽

Gland Function ◽

Large Rearrangements

Целью исследования стал анализ частоты протяженных перестроек гена CFTR и клинико-лабораторных характеристик пациентов с протяженными перестройками гена CFTR. В Регистр больных муковисцидозом РФ 2017 г. включены данные 3096 пациентов из 81 региона РФ, у которых выявлено 196 патогенных вариантов гена CFTR. Патогенные варианты обнаруживаются как в кодирующих, так и в интронных областях, и в регуляторных регионах гена CFTR. В гене CFTR относительно мало (около 2,5%) протяженных перестроек, но среди мутантных хромосом, в которых генетические варианты не были идентифицированы стандартными методами, такие перестройки составляют до 20%. По данным Регистра 2017 г. выявлен 21 пациент, несущий в своем генотипе крупные перестройки. Перестройки CFTRdele12,13del16, CFTRdele19-22(17а-19), CFTRdele8(7*), CFTRdele2-8(2-7*) ранее не были описаны в международных базах данных. Клиническая характеристика больных с протяженными перестройками не отличалась по основным признакам от пациентов с «тяжелыми» генотипами. Наличие в генотипе пациентов с протяженными перестройками варианта нуклеотидной последовательности гена CFTR, определяющего сохранную функцию поджелудочной железы, обусловило отсутствие у них панкреатической недостаточности. The aim of the study was to analyze large rearrangements in the CFTR gene in patients with cystic fibrosis in the Russian Federation in 2017. The Cystic Fibrosis Patients Registry of the Russian Federation for 2017 includes data from 3096 patients from 81 regions of the Russian Federation. To date, more than 2,000 mutations or variants of the nucleotide sequence of the CFTR gene have been described. In the Cystic Fibrosis Patients Registry of the Russian Federation for 2017, 196 pathogenic CFTR variants are given. Pathogenic variants are found both in the coding and in the intron regions, and in the regulatory regions of the CFTR gene. The CFTR gene has relatively few (about 2.5%) large rearrangements, but among mutant chromosomes in which genetic variants were not identified by standard methods, such rearrangements account for up to 20%. According to the Registry of 2017, 21 patients were identified that carried large rearrangements in their genotype. The rearrangements CFTRdele12,13del16, CFTRdele19-22 (17a-19), CFTRdele8 (7*), CFTRdele2-8 (2-7*) are not described in international databases. The clinical characteristics of patients with extensive rearrangements in the genotype did not differ in basic characteristics from patients with “severe” genotypes. The presence of a genetic variant in the genotype that determines the preserved function of the pancreas leads to the preservation of gland function in patients with large rearrangements in the genotype.

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INFLUENCE OF GENE POLYMORPHISM OF THE 1st PHASE OF XENOBIOTICS METABOLISM ON ANTIBACTERIAL THERAPY EFFICACY IN PATIENTS WITH CYSTIC FIBROSIS HOMOZYGOUS FOR F508DEL MUTATION OF CFTR GENE

PEDIATRIA Journal named after G N SPERANSKY ◽

10.24110/0031-403x-2018-97-2-94-98 ◽

2018 ◽

Vol 97 (2) ◽

pp. 94-98

Author(s):

O.G. Novoselova ◽

◽

N.V. Petrova ◽

E.I. Kondratyeva ◽

S.A. Krasovskii ◽

...

Keyword(s):

Cystic Fibrosis ◽

Gene Polymorphism ◽

Antibacterial Therapy ◽

Cftr Gene ◽

Therapy Efficacy

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CFTR Cooperative Cis-Regulatory Elements in Intestinal Cells

International Journal of Molecular Sciences ◽

10.3390/ijms22052599 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2599

Author(s):

Mégane Collobert ◽

Ozvan Bocher ◽

Anaïs Le Nabec ◽

Emmanuelle Génin ◽

Claude Férec ◽

...

Keyword(s):

Gene Expression ◽

Cystic Fibrosis ◽

Gene Regulation ◽

Genetic Diseases ◽

Regulatory Elements ◽

Cftr Gene ◽

Intestinal Cells ◽

Cooperative Effects ◽

Cis Acting ◽

Study Techniques

About 8% of the human genome is covered with candidate cis-regulatory elements (cCREs). Disruptions of CREs, described as “cis-ruptions” have been identified as being involved in various genetic diseases. Thanks to the development of chromatin conformation study techniques, several long-range cystic fibrosis transmembrane conductance regulator (CFTR) regulatory elements were identified, but the regulatory mechanisms of the CFTR gene have yet to be fully elucidated. The aim of this work is to improve our knowledge of the CFTR gene regulation, and to identity factors that could impact the CFTR gene expression, and potentially account for the variability of the clinical presentation of cystic fibrosis as well as CFTR-related disorders. Here, we apply the robust GWAS3D score to determine which of the CFTR introns could be involved in gene regulation. This approach highlights four particular CFTR introns of interest. Using reporter gene constructs in intestinal cells, we show that two new introns display strong cooperative effects in intestinal cells. Chromatin immunoprecipitation analyses further demonstrate fixation of transcription factors network. These results provide new insights into our understanding of the CFTR gene regulation and allow us to suggest a 3D CFTR locus structure in intestinal cells. A better understand of regulation mechanisms of the CFTR gene could elucidate cases of patients where the phenotype is not yet explained by the genotype. This would thus help in better diagnosis and therefore better management. These cis-acting regions may be a therapeutic challenge that could lead to the development of specific molecules capable of modulating gene expression in the future.

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A Peptide-Nucleic Acid Targeting miR-335-5p Enhances Expression of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Gene with the Possible Involvement of the CFTR Scaffolding Protein NHERF1

Biomedicines ◽

10.3390/biomedicines9020117 ◽

2021 ◽

Vol 9 (2) ◽

pp. 117

Author(s):

Anna Tamanini ◽

Enrica Fabbri ◽

Tiziana Jakova ◽

Jessica Gasparello ◽

Alex Manicardi ◽

...

Keyword(s):

Cystic Fibrosis ◽

Nucleic Acid ◽

Peptide Nucleic Acid ◽

Stop Codon ◽

Scaffolding Protein ◽

Cftr Gene ◽

Scaffolding Proteins ◽

Transmembrane Conductance Regulator ◽

Transmembrane Conductance ◽

Cystic Fibrosis Transmembrane

(1) Background: Up-regulation of the Cystic Fibrosis Transmembrane Conductance Regulator gene (CFTR) might be of great relevance for the development of therapeutic protocols for cystic fibrosis (CF). MicroRNAs are deeply involved in the regulation of CFTR and scaffolding proteins (such as NHERF1, NHERF2 and Ezrin). (2) Methods: Content of miRNAs and mRNAs was analyzed by RT-qPCR, while the CFTR and NHERF1 production was analyzed by Western blotting. (3) Results: The results here described show that the CFTR scaffolding protein NHERF1 can be up-regulated in bronchial epithelial Calu-3 cells by a peptide-nucleic acid (PNA) targeting miR-335-5p, predicted to bind to the 3′-UTR sequence of the NHERF1 mRNA. Treatment of Calu-3 cells with this PNA (R8-PNA-a335) causes also up-regulation of CFTR. (4) Conclusions: We propose miR-335-5p targeting as a strategy to increase CFTR. While the efficiency of PNA-based targeting of miR-335-5p should be verified as a therapeutic strategy in CF caused by stop-codon mutation of the CFTR gene, this approach might give appreciable results in CF cells carrying other mutations impairing the processing or stability of CFTR protein, supporting its application in personalized therapy for precision medicine.

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