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C Verlingue

Publications and source records attributed to C Verlingue.

33 records · Page 2Linked to original sources

Association of 1078 del T cystic fibrosis mutation with severe disease.

Apart from the high frequency of the delta F508 mutation (81.81%) in Breton cystic fibrosis chromosomes, one mutation, 1078 del T, is also observed frequently (4.96%) in this group, in comparison with the rest of the French where it occurs with a frequency of 0.57%. These two mutations account for more than 86.5% of the total CF mutations identified on Breton chromosomes. We have conducted an unblinded retrospective analysis of 25 patients with the 1078 del T mutation and compared their phenotypes with those of a group of 70 delta F508 homozygous patients. Both groups of patients had the same ethnic origin and were regularly attending the same CF centre in Brittany, which makes this sample highly homogeneous despite the small size. The 1078 del T mutation appeared to be associated with severe presentation of the disease with, however, a trend to reduced mortality and less Pseudomonas aeruginosa colonisation.

Adolescent↗

[Cystic fibrosis gene mutations in the West of France: clinical application].

The cystic fibrosis transmembrane conductance regulator (CFTR) gene, responsible for the cystic fibrosis phenotype when both alleles are mutated, was cloned and sequenced in 1989. Since then, more than 400 mutations have been reported in the gene, although most of these are rare. We have systematically analysed the entire coding sequence of the CFTR gene in a cohort of patients originating from the West of France (Caen, Brest and Nantes). More than 450 CF children, 914 chromosomes in all, have been exhaustively studied in the three centers. We have been able to characterize more than 90% of the mutations, respectively 93.5%, 99% and 95.8%. Despite the large diversity in the CFTR mutations occurring in CF patients from this area, these results can help to improve genetic counselling, prenatal diagnosis as well as our understanding of the molecular basis of the pathophysiology of cystic fibrosis.

Child↗

Asymptomatic carrier of two CFTR mutations: consequences for prenatal diagnosis?

The cystic fibrosis (CF) gene has been observed to have the highest frequency of mutations in the Caucasian population. Prenatal diagnosis can now be performed with a high degree of accuracy since the identification of most of the gene's mutations, as well as the characterization of intragenic markers. However, the observation of a distribution of clinical phenotypes increases the need to identify a mild phenotype and avoid false-negative diagnosis. By screening most of the exons of the CFTR gene, we showed that a supposed obligate carrier of CF was in fact an asymptomatic affected woman.

Base Sequence↗

Screening for cystic fibrosis in dried blood spots of newborns.

We propose a newborn cystic fibrosis (CF) screening test based on the analysis of dried blood spot DNA by a strategy involving simple or multiplex denaturing gradient gel electrophoresis (DGGE) of PCR products of CFTR gene fragments, in conjunction with the immunoreactive-trypsin (IRT) assay. From May 1988 to May 1992 we have performed a neonatal screening programme of 42,000 newborns in Brittany. We identified 450 infants with an elevated IRT level. From this cohort, to evaluate the feasibility of measuring IRT in conjunction with mutation analysis in Guthrie cards, a pilot study was initially conducted on 200 individuals with normal IRT and 150 with raised IRT levels. Furthermore, a retrospective study was performed on 189 IRT positive cards, involving mutation scanning of exons 10 and 11 of the CFTR gene, which contains a number of frequent mutations including the deletion delta F508. We show that this approach has several implications for neonatal CF screening especially in decreasing the recall rate and detecting CF carriers.

Algorithms↗

Identification of 12 novel mutations in the CFTR gene.

Over 200 mutations, besides the deletion delta F508, have been identified in the CFTR gene and are known to cause CF. In order to characterize the molecular defects of non delta F508 CF chromosomes of various French origin, we have combined the techniques of denaturing gradient gel electrophoresis (DGGE) and direct sequencing to screen for mutations in the whole coding sequence of the CFTR gene corresponding to the 27 exons and their exon-intron boundaries. This approach enabled us to identify 12 novel mutations which are described here. We have systematically tested a large number of other nucleotide changes distributed in the 27 exons, each of them was clearly detected. These data support the notion that the DGGE conditions we have defined for screening coding sequence of the CFTR gene allows the identification of most of, if not all, the CFTR gene mutations.

Base Sequence↗

Genotype analysis of adult cystic fibrosis patients.

To assess the relationship between the genotype and phenotype of adult CF patients we have selected from a group of 512 CF patients attending centres in France, all these of greater than 35 years. We have analysed the entire coding sequence of their CFTR genes. The complete genotype was determined in 7 of the 8 patients and clinical data regarding pancreatic, respiratory and reproductive function were carefully evaluated. All these patients are compound heterozygote, seven carrying the delta F508 and one the G542X on one allele. The other allele carried is: (i) a missense mutation located in exons coding for transmembrane region in five patients [R334W (1); I336K (2); R117H (1); H1054D (1)]; (ii) a splice mutation in two patients [2789 + 5G-->A], (iii) an uncharacterised mutations in one patient. These results strongly suggest less severe CF phenotype to be associated with these mutations and strengthen the hypothesis that less severe phenotype are genetically determined.

Adult↗

Detection of over 98% cystic fibrosis mutations in a Celtic population.

We have conducted a large systematic study of 365 cystic fibrosis (CF) chromosomes in a Celtic population from Brittany, France, in which we have been able to identify more than 98% of the cystic fibrosis gene mutations. We detected 19 different CFTR mutations located in 9 exons. Eleven of these mutations have not been described previously and nine of them are presented in this study. The denaturing gradient gel electrophoresis strategy we have used, can be applied to other populations suggesting that population screening for CF on a large scale might be possible.

Base Sequence↗

[Mucoviscidosis: current diagnostic possibilities. Applications in perinatology].

The gene of cystic fibrosis is localised on the long arm of chromosome 7. DNA probes placed close to the gene enable a study of restriction polymorphism to follow the transmission of the gene in index families. It is now possible to counsel those families, who already have an affected child, with an early antenatal diagnosis at ten weeks after the last period. In our personal experience, based on a study of the genotype of 48 families, 70% were informative when they were studied by two probes corresponding to the local pJ3.11 and met. When the latter probes Km19-XV2c were studied concurrently useful information was achieved in 96%. DNA analysis non enables the detection of the chromosome carrying the deleterious gene in practically every family where there is a child suffering from the disease.

Chromosomes, Human, Pair 7↗

[Linkage disequilibrium and DNA markers associated with the gene for cystic fibrosis].

R.F.L.P. (Restriction Fragment Length Polymorphism) observed with tightly linked probes to the CF gene allows us to calculate the standardised linkage disequilibrium between CF and these markers. This approach in combination with others strategies permits to situate the gene between D9 and G2. The conditional probabilities observed with these haplotypes modify the classical genetic of CF.

Cystic Fibrosis↗

HLA class II genes polymorphism in DR4 giant cell arteritis patients.

We have previously reported a significant increase of HLA-DR4 antigen frequency in giant cell arteritis (GCA). This finding suggested an important role of immunogenetic factors in this syndrome. Recent data suggest that inherited susceptibility to several autoimmune diseases was associated with specific DR4 associated DQ beta alleles. DNAs from 27 DR4 positive patients with GCA were digested with Taq I and Bam HI, analysed on 0.7% agarose gel and hybridized with DR beta, DQ alpha and DQ beta probes. DR beta hybridization produced no variant detectable within DR4. DQ beta probe confirmed two clusters among DR4 associated DQW3 alleles: DQW 3.1 (Bam HI 360 Kb) and DQw 3.2 (Taq I 1.9 Kb and Bam HI 11 Kb). Among our 27 DR4 positive patients, 34% were DQW 3.1 and 66% were DQW 3.2. These frequencies are the same as those observed in healthy controls.

DNA↗

[Gougerot-Sjögren's syndrome. Clinical and biological correlations with the serology of Yersinia infections].

An unusual case of Sjögren's syndrome (SS) induced or revealed by a Yersinia pseudotuberculosis serotype IV infection has prompted the authors to undertake a retrospective study of 32 patients with that syndrome. High titers of antibodies to Y. pseudotuberculosis serotype IV (greater than 1/200 th) were found in 4 patients with primary Sjögren's syndrome and Sharp's syndrome. Seven other patients (5 with primary Sjögren's syndrome, 1 with systemic lupus erythematosus and 1 with Sharp's syndrome) had positive serology with low titres, of doubtful significance. Serology was negative in the 20 remaining patients. Nine out of 25 patients had anti-thyroid antibodies, and their relationship with positive Y. pseudotuberculosis IV serology is discussed. The responsibility of the infection in the induction or disclosure of Sjögren's syndrome may be considered. However, since the syndrome frequently develops before serology becomes positive (8/12 cases with a 1 to 6 years' follow-up), an alternative hypothesis would be that diminished digestive defences in Sjögren's syndrome result in an increased frequency of Yersinia infections.

Adult↗

Prenatal diagnosis of cystic fibrosis in different European populations: application of denaturing gradient gel electrophoresis.

The cystic fibrosis transmembrane regulator gene, one of the most commonly mutated in the European population, was cloned in 1989 and since then has been extensively analysed in patients of various ethnic backgrounds. We have screened the entire coding sequences of the cystic fibrosis transmembrane regulator gene and identified many mutations and polymorphisms. In this paper we propose a general strategy to improve prenatal diagnosis and genetic counselling of cystic fibrosis (CF). As this approach based on denaturing gradient gel electrophoresis is adaptable to different populations, it greatly increases the sensibility and specificity of CF prenatal diagnosis.

Chorionic Villi Sampling↗

[Direct diagnosis of predominant mutation delta F508 associated with the mucoviscidosis gene].

The cystic fibrosis locus was mapped on the long arm of the chromosome 7 in 1985. It has recently been cloned and a three base pair deletion has been recognized as the mutation associated with the majority of CF chromosomes (delta F508). CF haplotypes previously defined with tightly associated DNA markers were analysed using PCR (Polymerase Chain Reaction) and allele specific oligonucleotides to determine the presence or absence of this mutation. This mutation was found on 80% of our CF chromosomes and associated predominantly with the B haplotypes. The detection of this mutation is now a major improvement for carrier detection and prenatal diagnosis of the disease.

Adult↗