Cystic fibrosis detection in high-risk Egyptian children and CFTR mutation analysis

Clinical manifestation, laboratory findings, and outcome of children with cystic fibrosis over a 10-year period in South Iran

Background

Cystic fibrosis (CF) is a monogenic hereditary disease with diverse complications, which substantially reduce the quality of life and longevity of patients. With regard to the scarcity of information on epidemiological aspects of this disease in Iran, we aimed to examine the current status of pediatric CF patients in a tertiary referral center in south Iran.

Results

Medical records of 105 patients (51% female) with the mean age of 16.3 ± 34.4 months were reviewed. Twelve patients (13.3%) had siblings with CF. Failure to thrive and respiratory symptoms were the most common presentations. Elevated liver enzymes and steatorrhea were detected in over half of tested patients, while abnormal serum albumin level, urinalysis, positive urine cultures, and positive acute phase reactants were noticed in less than half of the patients. Mild increase in pulmonary artery blood pressure was the most common finding of echocardiography. Increased liver echogenicity was the top finding of abdominopelvic sonography. Out of 42 available patients, 19 (45.2%) died with the mean age of 54.4 ± 101.8 months. The highest rate of mortality was observed in the 2–6 years old age group (42.9%).

Conclusion

Increased liver echogenicity was the most common finding in hepatobiliary evaluation. Mild increase in pulmonary artery blood pressure was the most common finding of echocardiography.

Screening for the Most Common Mutations of CFTR Gene among Egyptian Children with Difficult-to-Treat Asthma

Cystic fibrosis (CF) is panethnic autosomal recessive disease that affects the exocrine glands of pancreas, lungs, and intestine. It is often misdiagnosed in developing countries as difficult-to-treat asthma. We enrolled 150 Egyptian families with one or more probands who were complaining of difficult-to-treat asthma, and 112 cases were studied extensively through history taking including pedigree construction and clinical examination. In addition, spirometry and computed tomography of the chest were done in selected cases. All cases were subjected to quantitative sweat chloride test and molecular screening for the three most common mutations of cystic fibrosis transconductance regulator ( CFTR ) gene ( ΔF508 , G542X , W1282X ) using amplification refractory mutation system (ARMS) technique. Probands of difficult-to-treat asthma comprised 66 males and 46 females; their age range was 1 to 14 years. Sixty-one probands (54.5%) were carriers of one or more of the studied mutations (36 cases and 25 carriers). Six carriers of single mutations had mild respiratory symptoms and negative sweat test. The most common allele was ΔF508 , 60 alleles in 56 individuals (4 were homozygous ΔF508 / ΔF508 ) followed by W1282X in 25 individuals and G542X in 12 individuals. Allele W1282X had an increased risk of recurrent chest infection and bronchiectasis. Moreover, cases with two mutations had more severe symptoms compared with those with a single mutation. CFTR mutations and CF-related syndromes are not rare as thought in Egypt, especially among the high-risk difficult-to-treat asthma. The readily available ARMS technique is recommended for ΔF508 and/or W1282X screening on priority basis among these children.

Spectrum of mutations of cystic fibrosis in the 22 Arab countries: A systematic review

Cystic fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the CFTR gene, with various clinical manifestations that affect pulmonary, digestive, exocrine and male reproductive functions as well as the bones and kidneys. This study aimed to reveal the spectrum of CFTR gene mutations in Arab CF patients and their corresponding clinical phenotypes among the 22 Arab countries. We searched four literature databases (PubMed, Science Direct, Web of Science and Scopus) from their times of inception to January 2018. All possible search terms were used to encompass the different clinical phenotypes, disease incidences, CFTR mutations, ages and consanguinity rates of CF patients in the 22 Arab countries. Our search strategy identified 678 articles; of these, 72 were eligible for this systematic review. We retrieved data from 18 Arab countries; only 1766 Arab patients with CF were identified, even after additional searches using Google and Google Scholar. The search uncovered a wide spectrum of mutations, some of which are shared with other ethnic groups and some unique to Arab patients. Although the clinical phenotypes of Arab patients were typical of CF, several distinct phenotypes were reported. Despite the rarity of genetic epidemiological studies of CF patients among the 22 Arab nations, the disease is frequently reported in Arab countries where consanguineous marriage is common. Therefore, significant attention should be paid to this problem by implementing carrier and premarital screening, newborn screening and genetic counselling.

Cystic fibrosis in Tunisian children: a review of 32 children

Background

Cystic fibrosis is rare in Tunisia. Its diagnosis requires experienced specialists. Its prognosis is poor in developing countries.

Objectives

To study the epidemiologic, clinical, genetic features and the therapeutic challenges of cystic fibrosis in Tunisian children.

Methods

Covering a period of 21 years, this retrospective study included all patients with a definite diagnosis of cystic fibrosis from the Pediatrics Department B of The Children's Hospital of Tunis.

Results

Data from 32 children (14 boys and 18 girls) were collected. The diagnosis was made during the first year of life in 28 cases. Meconium ileus was found in 5 cases, respiratory manifestations in 22 cases, chronic diarrhea in 19 cases, faltering growth in 17 cases and a pseudo Barter syndrome in 2 cases. The sweat chloride test was positive in all cases. The most frequent mutation was F508del (56% of cases). Respiratory complications marked the outcome. Among our 32 patients, 15 patients (50%) died at an average age of 5 years and 3 months, mainly due to respiratory failure. The mean age of the surviving patients was 5 years.

Conclusion

Cystic fibrosis prognosis is poor in our series compared to developed countries due to the longer diagnostic delay and the limited therapeutic options.

Clinical and laboratory profile of children with Cystic Fibrosis: Experience of a tertiary care center in Pakistan

Objective:

To determine the clinical presentation, diagnostic investigations and laboratory workup done in admitted children with cystic fibrosis at Aga Khan University Hospital Karachi, Pakistan.

Methods:

This is athree years retrospective study from January 2013 to December 2015 conducted at The Aga Khan University Hospital Karachi Pakistan, enrolling admitted patient from birth to 15 years of either gender, diagnosed with CF on the basis of clinical features and positive sweat chloride test. Different clinical presentations were noted including initial presentations. Sweat chloride values more than 60mmol/L were labeled as positive and consistent with diagnosis of CF. Available Delta F-508 mutation analyses were noted. Relevant laboratory and radiological investigations including sputum culture and HR-CT chest findings were documented. Results were analyzed using SPSS version 20.

Results:

Total 43 children were selected according to the inclusion criteria. Chronic cough (69.76%) was the most common initial clinical presentation. Mean age at onset of symptoms was 14.41± 26.18 months and mean age at diagnosis was 47.20 ± 45.80 months Respiratory features were most common in our cohort including chronic productive cough (90.71%), recurrent bronchopneumonia (72.09%) and asthma like presentation (44.19%) with wheezing and cough. 86% patients presented with failure to thrive. Gastroenterological features including steatorrhea were seen in 55.81% patients and 44.19% patients had abdominal distension. Mean sweat chloride value in our population was 82.70± 22.74. Gene analysis for Delta F-508 was identified in 12 (27.90%) patients. Bronchiectatic pulmonary changes on HRCT were seen in 18 patients (41.86%). Pseudomonas grew in 12 patients (27.90%) in sputum cultures at the time of diagnosis.

Conclusion:

Respiratory presentations predominate in CF children followed by gastrointestinal features. Nearly half of our patient had bronchiectatic changes on CT scan chest and more than quarter had pseudomonas colonization in the airways at the time of diagnosis. Delta F-508 mutation was found to be uncommon in our study population. There is significant delay in diagnosing patients with CF.

Assessment of Correlation between Sweat Chloride Levels and Clinical Features of Cystic Fibrosis Patients

INTRODUCTION

Cystic Fibrosis (CF) is an autosomal recessive disorder and the incidence of this disease is undermined in Northern India. The distinguishable salty character of the sweat belonging to individuals suffering from CF makes sweat chloride estimation essential for diagnosis of CF disease.

AIM

The aim of this prospective study was to elucidate the relationship of sweat chloride levels with clinical features and pattern of CF.

MATERIALS AND METHODS

A total of 182 patients, with clinical features of CF were included in this study for quantitative measurement of sweat chloride. Sweat stimulation and collection involved pilocarpine iontophoresis based on the Gibson and Cooks methodology. The quantitative estimation of chloride was done by Schales and Schales method with some modifications. Cystic Fibrosis Trans Membrane Conductance Regulator (CFTR) mutation status was recorded in case of patients with borderline sweat chloride levels to correlate the results and for follow-up.

RESULTS

Out of 182 patients having clinical features consistent with CF, borderline and elevated sweat chloride levels were present in 9 (5%) and 41 (22.5%) subjects respectively. Elevated sweat chloride levels were significantly associated with wheeze, Failure To Thrive (FTT), history of CF in Siblings, product of Consanguineous Marriage (CM), digital clubbing and steatorrhoea on univariate analysis. On multivariate analysis only wheeze, FTT and steatorrhoea were found to be significantly associated with elevated sweat chloride levels (p<0.05). Among the nine borderline cases six cases were positive for at least two CFTR mutations and rest of the three cases were not having any mutation in CFTR gene.

CONCLUSION

The diagnosis is often delayed and the disease is advanced in most patients at the time of diagnosis. Sweat testing is a gold standard for diagnosis of CF patients as genetic mutation profile being heterozygous and unlikely to become diagnostic test.

Mutation spectrum of Egyptian children with cystic fibrosis

Objective

To know the common CFTR mutations in the Egyptian patients with cystic fibrosis as it was previously thought to be uncommon disease in Egypt.

Methods

This is a cross sectional study of 60 patients diagnosed as cystic fibrosis by sweat chloride testing. They were enrolled from the Allergy and Pulmonology Unit Children’s Hospital Cairo University. They were screened for the presence of the frequent 36 mutations in Caucasians by reverse hybridization line probe technique, using INNO-LiPACFTR19 and CFTR17 + Tn kits.

Results

Most of patients presented with classic manifestations of CF such as variable pulmonary disease and pancreatic insufficiency, and hepatomegaly with or without ascites. The mutations detected were F508 del (58 %), 2183AA/G (10 %), N1303K (6 %), I148T (4 %), W1282X (4 %), G155D (2 %), CFTRdel2-3 (21 KB) (2 %), 3199del6 (2 %), R347P (2 %). Unique to the Egyptian population are these mutations R1162X and A544E (6, 4 %) respectively they were found in our cohort study and were not reported elsewhere in the Arab population till now. There was no association between the initial clinical presentation of CF and the genotypes detected.

Conclusion

The F508 del is still the most commonly encountered mutation (58 %), however other rare mutations were identified where each ranged from (2 to 10 %).

Infection in cystic fibrosis: impact of the environment and climate

In many countries numbers of adults with cystic fibrosis (CF) exceed that of children, with median survival predicted to surpass 50 years. Increasing longevity is, in part, due to intensive therapies including eradication of early infection and suppressive therapies and pulmonary exacerbations. Initial infections with common CF pathogens are thought to arise from the natural environment. We review the impact of climate and environment on infection in CF. Specifically, several studies indicate that higher ambient temperatures, proximity to the equator and the summer season may be linked to the increased prevalence of Pseudomonas aeruginosa in people with CF. The environment may also play an important role in the acquisition of Gram negative organisms other than P. aeruginosa. There is emerging data suggesting that climatic and environmental factors are likely to impact on the risk of infection with NTM and fungi in people which are found extensively throughout the natural environment.

Molecular screening of CFTR gene in Egyptian patients with congenital bilateral absence of the vas deferens: a preliminary study

In the current study, we enrolled 14 Egyptian infertile males with isolated congenital bilateral absence of the vas deferens (CBAVD). Screening for the most commonly reported 36 CFTR mutations, and the intron 8 (T)n splice variant was performed by multiplex PCR followed by reversed hybridisation. Samples with the 5T variant were picked for DNA sequencing of intron 8/exon 9 region to identify the number of adjacent TG repeats. The p.Phe508del and the p.Ser1251Asn mutations were detected in heterozygous state in three patients (10.7% of alleles) and in one patient (3.6% of alleles), respectively, while the 5T variant was detected in five patients (28.6% of alleles). Among those five patients, four had TG12 repeats and one had TG13 repeats confirming the pathogenic penetrance of all 5T alleles in Egyptian CBAVD patients. The allelic frequencies of the mutations p.Phe508del, p.Ser1251Asn and the 5T variant in 60 Egyptian cystic fibrosis patients were 24.2%, 3.3% and 2.5% respectively. The mutation p.Ser1251Asn was detected for the first time in isolated CBAVD patient in our study. Due to the high prevalence of p.Phe508del mutation and 5T variant in Egyptian CBAVD patients, we recommend their screening initially, ideally followed by full CFTR gene sequencing in unidentified patients.

Next generation sequencing to determine the cystic fibrosis mutation spectrum in Palestinian population

An extensive molecular analysis of the CF transmembrane regulator (CFTR) gene was performed to establish the CFTR mutation spectrum and frequencies in the Palestinian population, which can be considered as an understudied population. We used a targeted Next Generation Sequencing approach to sequence the entire coding region and the adjacent sequences of the CFTR gene combined with MLPA analysis of 60 unrelated CF patients. Eighteen different CF-causing mutations, including one previously undescribed mutation p.(Gly1265Arg), were identified. The overall detection rate is up to 67%, and when we consider only CF patients with sweat chloride concentrations >70 mEq/L, we even have a pickup rate of 92%. Whereas p.(Phe508del) is the most frequent allele (35% of the positive cases), 3 other mutations c.2988+1Kbdel8.6Kb, c.1393-1G>A, and p.(Gly85Glu) showed frequencies higher than 5% and a total of 9 mutations account for 84% of the mutations. This limited spectrum of CF mutations is in agreement with the homozygous ethnic origin of the Palestinian population. The relative large portion of patients without a mutation is most likely due to clinical misdiagnosis. Our results will be important in the development of an adequate molecular diagnostic test for CF in Palestine.

Profile of cystic fibrosis in a single referral center in Egypt

It was generally believed that Cystic fibrosis (CF) is rare among Arabs; however, the few studies available from Egypt and other Arabic countries suggested the presence of many undiagnosed patients. The aim of the present study was to determine the frequency of CF patients out of the referred cases in a single referral hospital in Egypt. A total of 100 patients clinically suspected of having CF were recruited from the CF clinic of the Allergy and Pulmonology Unit, Children's Hospital, Cairo University, Egypt, throughout a 2 year period. Sweat chloride testing was done for all patients using the Wescor macroduct system for collection of sweat. Quantitative analysis for chloride was then done by the thiocyanate colorimetric method. Patients positive for sweat chloride (⩾60 mmol/L) were tested for the ΔF508 mutation using primer specific PCR for cystic fibrosis transmembrane conductance regulator (CFTR) gene. Thirty-six patients (36%) had a positive sweat chloride test. The main clinical presentations in patients were chronic cough in 32 (88.9%), failure to thrive in 27 (75%), steatorrhea in 24 (66.7%), and hepatobiliary involvement in 5 (13.9%). Positive consanguinity was reported in 50% of CF patients. Thirty-two patients were screened for ΔF508 mutation. Positive ΔF508 mutation was detected in 22 (68.8%) patients, 8 (25%) were homozygous, 14 (43.8%) were heterozygous, and 10 (31.3%) tested were negative. CF was diagnosed in more than third of patients suspected of having the disease on clinical grounds. This high frequency of CF among referred patients indicates that a high index of suspicion and an increasing availability of diagnostic tests lead to the identification of a higher number of affected individuals.