Frequency of common CFTR gene mutations in Venezuelan patients with cystic fibrosis (original) (raw)
Related papers
The Application of Clinical Genetics, 2016
The mutations in the CFTR gene found in patients with cystic fibrosis (CF) have geographic differences, but there are scant data on their prevalence in Venezuelan patients. This study determined the frequency of common CFTR gene mutations in a group of Venezuelan patients with CF. The 27 exons of the CFTR gene from 110 Venezuelan patients in the National CF Program were amplified and sequenced. A total of 36 different mutations were identified, seven with frequencies greater than 1%: p.Phe508del (27.27%), p.Gly542* (3.18%), c.2988+1G.A (3.18%), p.Arg334Trp (1.36%), p.Arg1162* (1.36%), c.1-8G.C (1.36%), and p.[Gly628Arg;Ser1235Arg](1.36). In 40% of patients, all with a clinical diagnosis of CF, no mutations were found. This report represents the largest cohort of Venezuelan patients with CF ever examined, and includes a wider mutation panel than has been previously studied in this population. Mutations common in Southern European populations predominate, and several new mutations were discovered, but no mutations were found in 40% of the cohort.
Background: CFTR gene mutations have worldwide differences in prevalence and data on Chilean patients is scarce. Methods: We studied 36 of the most common CFTR mutations in Chilean patients from the CF National Program [Programa Nacional de Fibrosis Quística (PNFQ)] of the Ministry of Health of Chile. Results: Two hundred and eighty-nine patients were studied. Fourteen different mutations were identified with an overall allele detection rate of 42.0%. Mutations with frequencies greater than 1% were p.F508del (30.3% of alleles), p.R334W (3.3%), p.G542X (2.4%), c.3849+10Kb CNT (1.7%), and p.R553X (1.2%). A north to south geographical gradient was observed in the overall rate of detection. Conclusions: Southern European CFTR mutations predominate in the Chilean population, but a high percentage of alleles remain unknown. Geographical heterogeneity could be explained in part by admixture. Complementary analyses are necessary to allow for effective genetic counselling and improve cost-effectiveness of screening and diagnostic tests.
Cystic fibrosis in Chilean patients: Analysis of 36 common CFTR gene mutations
Journal of Cystic Fibrosis, 2011
Background: CFTR gene mutations have worldwide differences in prevalence and data on Chilean patients is scarce. Methods: We studied 36 of the most common CFTR mutations in Chilean patients from the CF National Program [Programa Nacional de Fibrosis Quística (PNFQ)] of the Ministry of Health of Chile. Results: Two hundred and eighty-nine patients were studied. Fourteen different mutations were identified with an overall allele detection rate of 42.0%. Mutations with frequencies greater than 1% were p.F508del (30.3% of alleles), p.R334W (3.3%), p.G542X (2.4%), c.3849+10Kb CNT (1.7%), and p.R553X (1.2%). A north to south geographical gradient was observed in the overall rate of detection. Conclusions: Southern European CFTR mutations predominate in the Chilean population, but a high percentage of alleles remain unknown. Geographical heterogeneity could be explained in part by admixture. Complementary analyses are necessary to allow for effective genetic counselling and improve cost-effectiveness of screening and diagnostic tests.
Molecular genetics & genomic medicine, 2017
High heterogeneity in the CFTR gene mutations disturbs the molecular diagnosis of cystic fibrosis (CF). In order to improve the diagnosis of CF in our country, the present study aims to define a panel of common CFTR gene mutations by sequencing 27 exons of the gene in Ecuadorian Cystic Fibrosis patients. Forty-eight Ecuadorian individuals with suspected/confirmed CF diagnosis were included. Twenty-seven exons of CFTR gene were sequenced to find sequence variations. Prevalence of pathogenic variations were determined and compared with other countries' data. We found 70 sequence variations. Eight of these are CF-causing mutations: p.F508del, p.G85E, p.G330E, p.A455E, p.G970S, W1098X, R1162X, and N1303K. Also this study is the second report of p.H609R in Ecuadorian population. Mutation prevalence differences between Ecuadorian population and other Latin America countries were found. The panel of mutations suggested as an initial screening for the Ecuadorian population with cystic f...
CFTR mutations in Chilean cystic fibrosis patients
Human Genetics, 1994
An analysis of five of the most common cystic fibrosis (CF) mutations worldwide (ΔF-508, R-553X, G-551D, N-1303K and G-542X) was performed in 36 Chilean patients. Polymerase chain reaction (PCR) amplification of the DNA followed by allele specific restriction enzyme analysis was used for detection. The overall frequencies of the mutations in the chromosomes analyzed were 29.2% for ΔF-508 and 4.2% for R-553X (n=72). The G-542X, G-551D and N-1303 K mutations were absent in the Chilean sample. Our data suggest however that ΔF-508 is not the most common CF mutation in Chilean patients. ΔF-508 and R-553X account for only 33.4% of the alleles; 66.6% of them do not respond to the probes used and still remain uncharacterized.
Human Biology, 2005
To define mutations present in 23 exons and flanking intronic sequences of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in 95 patients from Rio de Janeiro, Brazil, we carried out single-strand conformation polymorphism analysis and automated direct sequencing. Mutation detection was achieved in 45% of the alleles presented, and complete genotyping (two mutated alleles) was accomplished in 34.7% of the patients. Twenty patients (21.1%) were found to carry only one mutation, whereas mutated alleles could not be observed in 42 patients (44.2%). Eleven mutations were found, of which four were characterized as rare mutations: P205S (1.05%), Y1092X (0.53%), S549R (0.53%), and S4X (0.53%). The DF508 mutation in this population sample showed a frequency of 28.42%. The low number of individuals (10 of 95; 10.5%) with compound heterozygous (DF508/non-DF508) genotypes could indicate the presence of another severe mutation leading to the premature death of these individuals. In 4 of the aforementioned 10 individuals with compound heterozygous genotypes, the D-7-2-1-2 (XV2c-KM19-IVS6a-TUB9-M470-T854) haplotype was defined.
Human Mutation, 2001
Cystic fibrosis (CF) is the most common autosomal recessive disease in the Caucasian population. The disease can be caused by one of the more than 900 different mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. However, the deletion of the phe508-codon is the most prevalent mutation observed. Our aim was to perform a screening for this mutation (∆ ∆ F508, or F508del) in the population of Mendoza, Argentina. For the screening, 1,000 blood samples were obtained from CF asymptomatic individuals and combined into 100 pools each containing 10 different blood samples. Pools containing at least one F508del carrier were detected by heteroduplex formation during the PCR amplification of exon 10. The PCR was designed to introduce a recognition site for a restriction enzyme that confirmed the presence of the deletion F508del in the positive pools. The results with this simple method indicate a frequency of carriers in the Mendoza population of 2.1% (1.3%-3.2, 95% confidence limits). The observed frequency of carriers is similar to that reported for European populations.
Analysis of CFTR gene mutations and cystic fibrosis incidence in the Ecuadorian population
Investigación clínica, 2007
Ecuador is one of the Latin American countries where cystic fibrosis has not been thoroughly studied. The goal of this study was to establish the incidence of this specific pathology and the incidence of the 29 most common European CF mutations in Ecuador's population. We performed a prospective-descriptive study with the intention of including patients registered at the Ecuadorian Cystic Fibrosis Foundation as well as the main pediatric hospitals in Ecuador. The inclusion criteria were clinical manifestations of cystic fibrosis plus two positive pilocarpine iontophoresis sweat tests (CI >60 mEq/L). We tested F508del mutation by heteroduplex method and then, we confirmed these results and searched for other 28 frequent European-mutations aside from F508del by a reverse dot blot technique (INNO-LiPA CFTR 29 + Tn). Sixty two unrelated patients were included. Both heteroduplex and reverse dot blot methods identified 53.22% of all mutations. The estimated Ecuadorian cystic fibros...
Spectrum of Mutations in the CFTR Gene in Cystic Fibrosis Patients of Spanish Ancestry
Annals of Human Genetics, 2007
We analyzed 1,954 Spanish cystic fibrosis (CF) alleles in order to define the molecular spectrum of mutations in the CFTR gene in Spanish CF patients. Commercial panels showed a limited detection power, leading to the identification of only 76% of alleles. Two scanning techniques, denaturing gradient gel electrophoresis (DGGE) and single strand conformation polymorphism/hetroduplex (SSCP/HD), were carried out to detect CFTR sequence changes. In addition, intragenic markers IVS8CA, IVS8-6(T)n and IVS17bTA were also analyzed. Twelve mutations showed frequencies above 1%, p.F508del being the most frequent mutation (51%). We found that eighteen mutations need to be studied to achieve a detection level of 80%. Fifty-one mutations (42%) were observed once. In total, 121 disease-causing mutations were identified, accounting for 96% (1,877 out of 1,954) of CF alleles. Specific geographic distributions for the most common mutations, p.F508del, p.G542X, c.1811 + 1.6kbA > G and c.1609delCA, were confirmed. Furthermore, two other relatively common mutations (p.V232D and c.2789 + 5G > A) showed uneven geographic distributions. This updated information on the spectrum of CF mutations in Spain will be useful for improving genetic testing, as well as to facilitate counselling in people of Spanish ancestry. In addition, this study contributes to defining the molecular spectrum of CF in Europe, and corroborates the high molecular mutation heterogeneity of Mediterranean populations.