Description of rare alleles of the CFTR gene in cystic fibrosis using functional tests and forskolin-induced swelling assay in rectal organoids

2021 ◽  
Vol 31 (2) ◽  
pp. 178-188
Author(s):  
A. S. Efremova ◽  
Yu. L. Melyanovskaya ◽  
N. V. Bulatenko ◽  
N. D. Odinaeva ◽  
A. V. Orlov ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Venous Blood ◽  
Clinical Manifestations ◽  
Rectal Biopsy ◽  
Hereditary Disease ◽  
Cftr Gene ◽  
Functional Assay ◽  
Functional Protein ◽  
Blood Leukocytes ◽  
Intestinal Organoids

Cystic fibrosis (CF) is a systemic hereditary disease caused by a mutation of the CFTR gene and characterized by damage to the glands of external secretion and severe dysfunctions of the respiratory system. The “severe” genotypes are associated with more pronounced and early clinical manifestations. The “mild” genotypes are associated with a delayed onset of clinical manifestations.Methods. An analysis of the medical history of patients with asymptomatic CF from the Russian CF centers was carried out. Rectal biopsy specimens were used for intestinal current measurement (ICM) and forskolin-induced swelling assay in intestinal organoids. DNA for sequencing was isolated from the venous blood leukocytes.Results. 2 CF patients with genotypes F508del/c.1584+18672A>G (patient 1, 12 years old) and F508del/G509D-E217G (patient 2, 3 years old) were examined. The diagnosis was based on neonatal screening. The ICM assay showed a reduced function of the CFTR channel: ΔISC for forskolin was 12.33 ± 2.35 μA/cm2 in patient 1 and 25 ± 3.37 μA/cm2 in patient 2. The negative response to carbachol and histamine reflects the entry of potassium ions into the cells, which is typical for CF. The assay in intestinal organoids showed that the amount of functional protein on the apical membrane of the intestinal epithelium increases both under the action of the potentiator and the corrector in both patients. The greatest effect is observed when the VX-770 and VX-809 are used together.Conclusion. The ICM functional assay and the forskolin-induced swelling assay in intestinal organoids are sensitive enough to determine the residual functional activity of the CFTR channel and clarify the diagnosis in difficult cases. The studied genetic variants c.1584+18672A>G and G509D-E217G belong to class IV – VI mutations. The clinical picture corresponds to the manifestations of “mild” mutations. The studied patients still attend the Russian cystic fibrosis centers.

scholarly journals Clinical and genetic features of cystic fibrosis patients with novel pathogenic variant CFTR c.1083G> A (p.Trp361*) and functional assessment of the activity of the chloride channel

2019 ◽  
pp. 9-18
Author(s):  
Е.И. Кондратьева ◽  
Ю.Л. Мельяновская ◽  
А.С. Ефремова ◽  
Н.В. Булатенко ◽  
Т.Б. Бухарова ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Russian Federation ◽  
Genetic Variant ◽  
Clinical Manifestations ◽  
Pathogenic Variant ◽  
Cftr Gene ◽  
Genetic Characteristics ◽  
Intestinal Organoids ◽  
The Russian Federation ◽  
First Time

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.

Clinical and genetic characteristics of rare pathogenic variants of the CFTR gene in Russian patients with cystic fibrosis

2021 ◽  
Vol 31 (2) ◽  
pp. 148-158
Author(s):  
A. Yu. Voronkova ◽  
Yu. L. Melyanovskaya ◽  
N. V. Petrova ◽  
T. A. Adyan ◽  
E. K. Zhekaite ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Genetic Variants ◽  
Pancreatic Insufficiency ◽  
Protein Energy Malnutrition ◽  
Molecular Genetic ◽  
Clinical Manifestations ◽  
Cftr Gene ◽  
Genetic Characteristics ◽  
Missense Variants ◽  
Pathogenic Variants

The variety of clinical manifestations of cystic fibrosis is driven by the diversity of the CFTR gene nucleotide sequence. Descriptions of the clinical manifestations in patients with the newly identified genetic variants are of particular interest.The aim of this study was to describe clinical manifestations of the disease with the newly identified genetic variants.Methods. Data from Registry of patients with cystic fibrosis in the Russian Federation (2018) were used. The data review included three steps — the search for frequent mutations, Sanger sequencing, and the search for extensive rearrangements by MLPA. 38 pathogenic variants were identified that were not previously described in the international CFTR2 database. We selected and analyzed full case histories of 15 patients with 10 of those 38 pathogenic variants: p.Tyr84*, G1047S, 3321delG, c.583delC, CFTRdele13,14del18, CFTRdele19-22, c.2619+1G>A, c.743+2T>A, p.Glu1433Gly, and CFTRdel4-8del10-11.Results. A nonsense variant p.Tyr84* was found in 5 patients (0.08 %). Two missense variants c.3139G>A were found in 2 siblings (0.03 %). The c.4298A>G was found in 1 patient. Other variants were detected in a single patient (0.02 %) each. They included two variants of a deletion with a shift of the reading frame 3321delG and c.583delC, two splicing disorders c.2619+1G>A and c.743+2T>A, three extended rearrangements CFTRdele19-22, CFTRdele13,14del18, and CFTRdel4-8del10-11. The last two variants include 2 rearrangements on one allele, which cause the severe course in two young children. 8 of the 10 variants are accompanied by pancreatic insufficiency (PI). Among patients with p.Tyr84*, one had ABPA, one had liver transplantation, and all had Pseudomonas aeruginosa infection. Nasal polyps were diagnosed in 2 patients with p.Tyr84*, 1 with G1047S, 1 with CFTRdel4-8del10-11, and 1 patient with 3321delG, who also had osteoporosis and cystic fibrosis-related diabetes (CFRD). 2 patients with PI with 3321delG and CFTRdel4-8del10-11 genetic variants, and 1 with PI with p.Glu1433Gly genetic variant had severe protein-energy malnutrition (PEM).Conclusion. Clinical manifestations of previously undescribed CFTR genetic variants were described. 5/10 genetic variants should be attributed to class I, 3/10 – to class 7 of the function classification of pathogenic CFTR gene variants associated with transcription and translation disruptions. Class of the identified missense variants c.3139G>A and c.4298A>G has not been established and requires further functional, cultural, and molecular genetic studies.

scholarly journals ORGANIZATION OF AID IN CYSTIC FIBROSIS PATIENTS IN THE NORTH-CAUCASIAN FEDERAL REGION

2019 ◽  
Vol 20 (2) ◽  
pp. 84-89
Author(s):  
E. V. Vodovozova ◽  
L. N. Ledeneva ◽  
N. I. Kapranov ◽  
T. A. Ponomareva ◽  
I. V. Polyakova ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Short Duration ◽  
Russian Federation ◽  
Social Problem ◽  
Clinical Manifestations ◽  
Hereditary Disease ◽  
The North ◽  
Regional Center ◽  
Therapeutic Measures ◽  
The Russian Federation

Cistic fibrosis (CF) is the hereditary disease, presenting the important medical social problem, related with timely diagnostics, the early disablement of patients, short duration of their life, need for a constant performing therapeutic measures and active clinic observation. In 2008 in the North-Caucasian Federal Region (NCFR), there was introduced the register of СF patients, in 2015 the data about patients residing in the Stavropol territory were sent for the introduction into the register of CF cases of the Russian Federation. The executed analysis showed the register of СF cases of the Russian Federation to be is insufficiently used in all NCFR regions, which makes impossible the processing of data about the special features of the course, the clinical manifestations, epidemiology, genetic inspection, microbiological monitoring and treatment of the disease in the region. The implemented analysis of the management of СF patients in NCFR, determines the need of creating the united regional center for the improvement of the centralized aid for considered patients.

CYSTIC FIBROSIS: ETIOLOGY, PATHOGENESIS, CLINICAL MANIFESTATIONS, RESULTS OF NEONATAL SCREENING AND GENETIC ASPECTS IN NORTH OSSETIA – ALANIA

2021 ◽  
Vol 100 (1) ◽  
pp. 222-228
Author(s):  
I.S. Tebieva ◽  
◽  
Z.K. Getoeva ◽  
N.V. Petrova ◽  
Yu.V. Gabisova ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Neonatal Screening ◽  
Clinical Manifestations ◽  
Population Characteristics ◽  
Cftr Gene ◽  
Sweat Glands ◽  
Multisystem Disease ◽  
Adequate Treatment ◽  
Economic Point ◽  
North Ossetia

Cystic fibrosis (CF) is a multisystem disease that affects the respiratory tract, gastrointestinal tract, liver, pancreas, salivary, sweat glands, reproductive system, caused by pathological variants of the CFTR gene located in the long arm of chromosome 7. Considering the fact that CF is the most common hereditary disease, transmitted in an autosomal recessive manner, threatening death and/or disability in case of late diagnosis, the study of population characteristics in different regions is important not only from an epidemiological, but also from a socio-economic point of view. High incidence of CF, the ability to identify the carrier of pathogenic CFTR gene variant, prenatal and preclinical diagnosis, adequate treatment and medical and social adaptation determine the need for organizing mass screening of newborns for this disease. Objective of this research is to evaluate the efficiency of neonatal screening for CF in RNO – Alania, to detect the frequency of its occurrence in the region, and to determine the molecular genetics features of CF in the population. A retrospective analysis of medical records of CF patients diagnosed before neonatal screening was carried out, as well as an analysis of the results of mass newborns screening for CF during 13 years from January 2007 to December 2019. Based on the analysis performed, it was found that the CF frequency in North Ossetia-Alania was 1:16369 live births, which is significantly lower than the average for Russia (1:9500).

Cystic Fibrosis: Pathophysiology of Lung Disease

2019 ◽  
Vol 40 (06) ◽  
pp. 715-726 ◽  
Author(s):  
Christelle Bergeron ◽  
André M. Cantin
Keyword(s):  
Cystic Fibrosis ◽  
Mucociliary Clearance ◽  
Current Knowledge ◽  
Clinical Manifestations ◽  
Autosomal Recessive Disorder ◽  
Cftr Gene ◽  
Susceptibility To Infection ◽  
Life Threatening ◽  
Cftr Protein ◽  
And Function

AbstractCystic fibrosis (CF) is a common, life-threatening, multisystemic, autosomal recessive disorder. In the last few years, giant steps have been made with regard to the understanding of CF pathophysiology, allowing the scientific community to propose mechanisms that cause the myriad of CF clinical manifestations. Following the discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in 1989, the structure and function of the CFTR protein were described. Since then, more than 2,000 variants of the CFTR gene and their impact on the amount and function of the CFTR protein have been reported. The role of the CFTR protein as an ion channel transporting chloride and bicarbonate and its repercussions on different epithelial cell-lined organs and mucus are now better understood. Mechanisms behind susceptibility to infection in CF have also been proposed and include abnormalities in the composition, volume and acidity of the airway surface liquid, changes in the submucosal gland's anatomy and function, and deficiencies in the mucociliary clearance system. Numerous hypotheses explaining the excessive inflammatory response in CF are also debated and involve impaired mucociliary clearance, persistent hypoxia, lipid abnormalities, protease and antiprotease disproportion, and oxidant and antioxidant imbalance. The purpose of this review is to summarize our current knowledge of CF pathophysiology, including significant historic discoveries and most recent breakthroughs, and to improve understanding and awareness of this fatal disease.

scholarly journals The spectrum of sensitization of children with cystic fibrosis

2019 ◽  
pp. 89-92
Author(s):  
E. A. Antonova ◽  
A. V. Goryainova ◽  
S. Yu. Semykin ◽  
T. A. Filatova
Keyword(s):  
Quality Of Life ◽  
Cystic Fibrosis ◽  
Genetic Diseases ◽  
Clinical Manifestations ◽  
Public Health Problem ◽  
Allergic Diseases ◽  
Diet Therapy ◽  
Hereditary Disease ◽  
Global Public Health

Cystic fibrosis is a hereditary disease that affects the quality of life of patients without proper treatment. It has been established that allergic diseases have become a global public health problem. Due to a variety of clinical manifestations that affect the development, health and quality of life, it is difficult to diagnose. Due to the high incidence of allergic problems, there is the problem of interrelationship of hereditary genetic diseases - cystic fibrosis and spectral sensitization of children suffering from morbidity in order to improve the algorithms, improve the condition and quality of life of patients, due to the appointment of proper diet therapy.

scholarly journals Aspirin and Some Other Nonsteroidal Anti-Inflammatory Drugs Inhibit Cystic Fibrosis Transmembrane Conductance Regulator Protein Gene Expression in T-84 Cells

1999 ◽  
Vol 8 (4-5) ◽  
pp. 219-227 ◽  
Author(s):  
Danielle Tondelier ◽  
Franck Brouillard ◽  
Joanna Lipecka ◽  
Régis Labarthe ◽  
Moëz Bali ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cystic Fibrosis ◽  
Chloride Transport ◽  
Clinical Manifestations ◽  
Cftr Gene ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Regulator Protein ◽  
Inflammatory Drugs ◽  
Anti Inflammatory

Cystic fibrosis (CF) is caused by mutations in the CF gene, which encodes CF transmembrane conductance regulator protein (CFTR), a transmembrane protein that acts as a cAMP-regulated chloride channel. The disease is characterized by inflammation but the relationship between inflammation, abnormal transepithelial ion transport, and the clinical manifestations of CF are uncertain. The present study was undertaken to determine whether three nonsteroidal anti-inflammatory drugs (NSAIDs) (aspirin, ibuprofen, and indomethacin) modulate CFTR gene expression in T-84 cells. Treatment with NSAIDs reduced CFTR transcripts, and decreased cAMP-stimulated anion fluxes, an index of CFTR function. However, the two phenomena occurred at different concentrations of both drugs. The results indicate that NSAIDs can regulate both CFTR gene expression and the function of CFTR-related chloride transport, and suggest that NSAIDs act via multiple transduction pathways.

scholarly journals CFTR Cooperative Cis-Regulatory Elements in Intestinal Cells

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.

Mucopolysaccharidosis III in Mainland China: natural history, clinical and molecular characteristics of 34 patients

2020 ◽  
Vol 33 (6) ◽  
pp. 793-802 ◽  
Author(s):  
Weijing Kong ◽  
Yan Meng ◽  
Liping Zou ◽  
Guang Yang ◽  
Jing Wang ◽  
...  
Keyword(s):  
Mental Retardation ◽  
Autosomal Recessive ◽  
Mainland China ◽  
Clinical Manifestations ◽  
Hereditary Disease ◽  
Molecular Characteristics ◽  
Speech Delay ◽  
Initial Symptoms ◽  
Mps Iii ◽  
Mps Iiia

AbstractObjectivesSanfilippo syndrome (Mucopolysaccharidosis III, MPS III) is a rare autosomal recessive hereditary disease, which is caused by lysosomal enzyme deficiency. This study was operated to investigate clinical and molecular characteristics of patients with MPS III, which will improve the diagnosis and treatment of MPS III.MethodThirty four patients with MPS III were assessed using clinical evaluation, questionnaire, and scoring system.ResultsAmong the 34 patients, 14 had MPS IIIA, 19 had MPS III B, and one had MPS III C. Speech delay (100%) and intellectual disability (100%) were the most prevalent clinical manifestations in this cohort, followed by hyperactivity (94.12%), hirsutism (91.18%), enlarged head circumference (73.52%), repeated diarrhea (67.64%), sparse teeth (67.64%), and Mongolian spots (64.71%). There were two clinical manifestations that were significantly different between IIIA and IIIB: Hepatosplenomegaly and serrated teeth. The most common initial symptoms at diagnosis were speech delay (52.94%), hyperactivity (35.29%), and mental retardation (29.41%). Genetic analysis of 25 patients was conducted, which identified 12 novel mutations.ConclusionWhen language retardation, mental retardation, and rough facial features occurred, MPS III should be considered. At same time, more examination should be operated, such as examination of changes in cranial magnetic resonance imaging of cerebral cortex atrophy. Hepatosplenomegaly and serrated teeth could be used clinically to preliminarily distinguish IIIA from IIIB.

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