A new approach for identifying non-pathogenic mutations. An analysis of the cystic fibrosis transmembrane regulator gene in normal individuals (original) (raw)

Screening for non-delta F508 mutations in five exons of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in Italy

American journal of human genetics, 1991

Analysis of exons 10, 11, 14a, 15, and 20 of the cystic fibrosis transmembrane conductance regulator (CFTR) gene by denaturing-gradient-gel electrophoresis (DGGE) allowed the identification of mutations causing cystic fibrosis (CF) in 25 of 109 non-delta F508 chromosomes, as well as identification of a number of polymorphisms and sequence variations. Direct sequencing of the PCR fragments which showed an altered electrophoretic behavior not attributable to known mutations has led to the characterization of four new mutations, two in exon 11, and one each in exons 15 and 20. Screening for the different mutations thus far identified in our patients by the DGGE analysis and other independent methods should allow detection of about 70% of the molecular defects causing CF in Italy. Mutations located in exons 11 and 20 account for at least 30% of the non-delta F508 mutations present in Italian CF patients.

Non-radioactive detection of the most common mutations in the cystic fibrosis transmembrane conductance regulator gene by multiplex allele-specific polymerase chain reaction

Human Genetics, 1992

A rapid, simple, nonradioactive method for detection of four common mutations causing cystic fibrosis (CF) has been developed combining multiplexing with allele-specific polymerase chain reaction amplification. This approach (MASPCR) provides an easy assay for direct genotyping of normal and mutant CF alleles in homozygotes and heterozygotes. The strategy involves multiplex PCR of exons 10, 11, and 21 within the cystic fibrosis transmembrane conductance regulator (CFTR) gene in a single reaction containing three common oligoprimers and either the four normal or four mutant oligos corresponding to the AF508, G551D, G542X, and N1303K mutations. Primers are chosen so that the size of the four PCR products differ, thereby facilitating detection on agarose gels following amplification in the same reaction. Patient samples are primed with either four normal or four mutant oligo mixtures, and PCR products run in parallel on gels to detect band presence or absence. This approach provides a simple and potentially automated method for cost-effective population screening.

The molecular analysis of mutations in exons 4, 11 and 21 of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in cystic fibrosis patients in Kermanshah, Iran

Journal of Kermanshah University of Medical Sciences, 2017

Introduction: Cystic fibrosis (CF) is a common genetic disorder in white populations with an autosomal recessive pattern, caused by mutations in the CFTR gene. The frequency of more than 1950 various mutations reported in the CFTR gene significantly varies in different populations. ∆F508 is a common mutation in exon 10, which is first addressed in the molecular analysis of the disease. Other exons are required to be investigated owing to failing to identify mutations in the patients. The present study was conducted to investigate mutations in exons 4, 11 and 21 of the CFTR gene using the sequencing method in CF patients in Kermanshah province, Iran. Methods: The present descriptive study was conducted on all patients with CF presenting to the medical genetics center in Kermanshah in 2010-2011. After taking blood samples and extracting DNA using saturated NaCl solution, sequences of exons were amplified using PCR and sequenced for identifying mutations. Results: The frequency of muta...

Distribution of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Mutations in a Cohort of Patients Residing in Palestine

PLOS ONE, 2015

Cystic fibrosis (CF) is an autosomal recessive inherited life-threatening disorder that causes severe damage to the lungs and the digestive system. In Palestine, mutations in the Cystic Fibrosis Transmembrane Conductance Regulator gene (CFTR) that contributes to the clinical presentation of CF are ill defined. A cohort of thirty three clinically diagnosed CF patients from twenty one different Palestinian families residing in the central and southern part of Palestine were incorporated in this study. Sweat chloride testing was performed using the Sweat Chek Conductivity Analyzer (ELITECH Group, France) to confirm the clinical diagnosis of CF. In addition, nucleic acid from the patients' blood samples was extracted and the CFTR mutation profiles were assessed by direct sequencing of the CFTR 27 exons and the intron-exon boundaries. For patient's DNA samples where no homozygous or two heterozygous CFTR mutations were identified by exon sequencing, DNA samples were tested for deletions or duplications using SALSA MLPA probemix P091-D1 CFTR assay. Sweat chloride testing confirmed the clinical diagnosis of CF in those patients. All patients had NaCl conductivity >60mmol/l. In addition, nine different CFTR mutations were identified in all 21 different families evaluated. These mutations were c.1393-1G>A, F508del, W1282X, G85E, c.313delA, N1303K, deletion exons 17a-17b-18, deletion exons 17a-17b and Q1100P. c.1393-1G>A was shown to be the most frequent occurring mutation among tested families. We have profiled the underling mutations in the CFTR gene of a cohort of 21 different families affected by CF. Unlike other studies from the Arab countries where F508del was reported to be the most common mutation, in southern/ central Palestine, the c.1393-1G>A appeared to be the most common. Further studies are needed per sample size and geographic distribution to account for other possible CFTR genetic alterations and their frequencies. Genotype/phenotype assessments are also recommended and finally carrier frequency should be ascertained.

Development and validation of a screening test for 12 common mutations of the cystic fibrosis CFTR gene

European Respiratory Journal, 1998

The results obtained using deoxyribonucleic acid (DNA) amplification-based tests must be accurate and reproducible. One such test that simultaneously detects any of 12 of the most common mutations of the cystic fibrosis transmembrane conductance regulator gene is presented in this report. An investigation was conducted into how changes of primer, DNA template and Taq DNA polymerase concentrations and of polymerase chain reaction annealing temperatures affect the test. A total of 383 DNA samples obtained from different laboratories was then examined. The preliminary studies defined the conditions under which accurate results are obtained even if the test is performed under suboptimal conditions. Subsequently, 377 (98.4%) of the DNA samples analysed were in full agreement with DNA typing results derived by other methods. The remaining 1.6% of samples were not mistyped, rather they were not scored owing to failure to detect control DNA sequences. These were also archival DNA preparatio...

Detection of mutations in Cuban cystic fibrosis patients

2008

Cystic Fibrosis (CF) is the most common autosomal recessive disease in Caucasian populations, with an incidence of 1 out of 5000 newborns in Cuba. Although cystic fibrosis transmembrane conductance regulator (cftr) gene was cloned and the mutation of this gene responsible for most CF cases, F508del was already identified by 1998, more than 1400 additional cftr mutations have been described. The mutations for the cftr gene among the Cuban CF patient population are highly heterogeneous. Therefore, we have used two screening techniques, denaturing gradient gel electrophoresis (DGGE) and single strand conformation polymorphism (SSCP) in order to detect and identify cftr sequence changes in this population. In the present study, 9 different mutations were detected in our patients, together with 4 previously described nucleotide sequence polymorphisms.

Identification of the commonest cystic fibrosis transmembrane regulator gene ΔF508 mutation: evaluation of PCR–single-strand conformational polymorphism and polyacrylamide gel electrophoresis

Biomedical Chromatography, 2006

In the present study we investigated whether single-strand conformational polymorphism (SSCP) and polyacrylamide gel electrophoresis (PAGE) could be used for the identification of the CFTR ∆F508 gene mutation, which is commonest in the Greek population. Using DNA from patients carrying this mutation, the appropriate 98 bp region of the CFTR gene was amplified by PCR and the reaction products were analysed by non-radioactive SSCP-electrophoresis using silver staining for band visualization and non-denaturating PAGE to confirm the results. SSCP electrophoretic analysis has been optimized for several parameters in order to achieve the best resolution. Single-strand DNA fragments gave a reproducible pattern of bands, characteristic for the particular mutation. Comparison of the obtain patterns with control samples allowed the detection of the ∆F508 mutation in the patients studied by SSCP assay and these results were confirmed by the independent method of PAGE. Although SSCP and PAGE can be used for detection of this mutation, PAGE resulted in more distinct patterns than SSCP. It is, therefore, proposed that PAGE can be reliably used for the detection and identification of such a mutation in patients provided that suitable controls are available. The applicability of PAGE to identification of the mutation in carriers, particularly useful for population screening, is also discussed.

An Overview of the Homozygous Cystic Fibrosis Transmembrane Conductance Regulator Mutation c.3700 A>G (p.Ile1234Val) in Qatar

Current Genetic Medicine Reports

Purpose of Review Cystic fibrosis (CF) is a monogenic recessive disease with multisystem involvement. The cause is a mutation in the gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The aim is to review the literature involving the CFTR I1234V mutation and to provide recommendations for future research activities. Recent Findings The prevalence rates of CFTR mutations vary across the globe. The CFTR I1234V mutation is the most common mutation in Qatar, and one of the most common in the Arabian Gulf region. Summary Areas for future research include testing of the CFTR transcript and activity levels in different samples including nasal cells and organoids. Another area is applying Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technology as a tool for gene editing.