PubMed Health⌕ Search

Biomedical subjects

C Ferec

Publications and source records attributed to C Ferec.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Gene mutations of cystic fibrosis in Brittany population].

Eighty percent of chromosomes from cystic fibrosis children in Brittany exhibit the major gene mutation (delta F 508) consisting in deletion of three nucleotide pairs. Eighty-seven chromosomes without the delta F 508 mutation were studied for as yet undescribed gene mutations. A large number of mutations were located in exons 10 and 11. Consequently, a global strategy for identifying mutations in these exons was developed. Analysis of pedigrees of cystic fibrosis patients in Brittany evidenced a clear founder effect. Appropriate prevention strategies will therefore be developed.

Cystic Fibrosis↗
PubMed1990

Frequency of the cystic fibrosis delta F508 mutation in a large sample of the French population.

We have determined the frequency of the cystic fibrosis (CF) delta F508 mutation in a large sample of CF patients originating from different areas of France, including the greater Paris, Brittany, Alsace, Lorraine and Rhône-Alpes regions. A total of 422 CF chromosomes were studied, and the defect was found to account for 75% of the mutant alleles. In the course of the survey, a rare nucleotide sequence polymorphism leading to an isoleucine to valine substitution at position 506 of the CF transmembrane conductance regulator protein has been characterized in an unaffected individual. Our data enable the evaluation of the probabilities that a chromosome negative for the delta F508 mutation carriers another CF defect.

Cystic Fibrosis↗
PubMed1990

A 3' splice site consensus sequence mutation in the cystic fibrosis gene.

In the cystic fibrosis (CF) gene, recently cloned, a three base pair deletion (delta F508) has been identified in a majority of CF patients. This deletion has been found in 80% of CF chromosomes in families from north west Brittany. In order to identify new mutations we have selected 43 chromosomes negative for the three base pair deletion from these families and directly sequenced exon 11 after DNA amplification by the polymerase chain reaction. We have detected a base change (G----A) at the 3' end of the consensus sequence of intron ten (namely 1717-1). This mutation destroys a splice site in the cystic fibrosis gene which probably produces a mutant allele. This single nucleotide mutation has been reported on two other CF chromosomes.

Cystic Fibrosis↗
PubMed1990

[Autosomal dominant polycystic kidney and genetic markers of chromosome 16].

The mutation for autosomal dominant polycystic kidney disease (APKD) has been mapped by linkage analysis on the distal part of the short arm of chromosome 16. We present in this study the results of linkage analysis using the two most tightly linked DNA markers (3'HVR and 24-1) in 183 members of 14 families of a same ethnic origin. We have constructed haplotypes using these two polymorphic probes, and compared the frequency of these on the normal and the affected chromosome. No evidence of linkage heterogeneity was found in our population.

Chromosome Mapping↗
PubMed1989

Confirmation of linkage disequilibrium between haplotype B (XV-2c, allele 1; KM-19, allele 2) and cystic fibrosis allele in the French population.

In 237 French families with cystic fibrosis (CF) restricted fragment length polymorphisms (RFLPs) were detected by two DNA probes, XV-2c and KM-19, which are tightly linked to the CF allele. As in other European populations linkage disequilibrium is found between the haplotype B (XV-2c, allele 1: KM-19, allele 2) and the CF allele. Linkage disequilibrium alters the probability that a person bearing a given haplotype is a carrier.

Cystic Fibrosis↗
PubMed1989

[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↗
PubMed1989

[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↗
PubMed1989

[Analysis of 112 haplotypes carrying the cystic fibrosis gene. Applications in genetic counseling].

Cystic fibrosis (CF) is always a common lethal genetic disease. The locus is localized to human chromosome 7q22-7q31. Genetic linkage between the CF locus and polymorphic DNA marker is used to realize family studies. We have genotyped 56 families (352 patients) with a CF child. The informativeness with the six markers (Met D/Taq I, Met H/Taq I, Met H/Msp 1, XV2c/Taq 1, km19/pst pJ 3.11/Msp 1) is important (96%). The linkage desequilibrium between alleles detected by XV2 c and Km 19 described by Estivill and al, is also showed in our population. The haplotype B (Km 19 = 6.6 kb, XV2 c = 2.1 kb) is present on 84% of our 112 CF chromosomes. We have established the frequencies of the 10 possible genotypes in the pool of the 112 CF chromosomes and in the pool of the normal chromosome and according to Bayes obtained the predictive positive value to be heterozygote. It is possible to precise the genetic counselling in these families.

Cystic Fibrosis↗
PubMed1988

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↗
PubMed1988

[Haplotypes associated with the cystic fibrosis gene (CF)].

The linkage relationships between the cystic fibrosis locus and six marker loci allowed us to build 122 haplotypes bearing the CF gene and to compare them to the 122 normal haplotypes. We obtained 13 different marker haplotypes associated with the CF chromosomes and 22 with the normals in our population. To examine the possibility of a correlation between the clinical and the genetical polymorphism of the disease haplotype analysis was carried out taking in account age at diagnosis, severity of the disease and a particular clinical subgroup such as meconium ileus or pancreatic sufficiency. The results showed that a particular haplotype (121) is predominant in the severe form of the disease. This may have implication in diagnosis and prognosis of the disease.

Chromosomes, Human, Pair 7↗
PubMed1988

[Approaching the gene of mucoviscidosis. New data].

We used 5 polymorphic probes strongly linked to the gene of cystic fibrosis (CF) to perform the genotypical study of 48 families with at least one child presenting with the disease. The last Km19 and XV2c probes showed a very important linkage imbalance with the CF gene (allele 2 = 6.6 kb of Km19/Pstl, chi 2 = 56; allele 1 = 2.1 kb of XV2c/Taql, chi 2 = 21). These two markers define a B haplotype which confers a relative risk of 55 to be gene carrier. From these data, the predictive value for an individual presenting with this haplotype to be heterozygous was computed to be 1/5. Presently, the risk of 1/20 for a randomized subject to be gene-carrier should be reexamined after study of this genotype. These results are very important practically, as they modify the classical data of genetic counselling concerning cystic fibrosis for the couples with a risk higher than 1/4.

Alleles↗
PubMed1988

[Prenatal diagnosis of mucoviscidosis. Contribution of DNA analysis of trophoblast biopsies].

The gene for cystic fibrosis has been localised on the long arm of chromosome 7. Genetic engineering techniques now make it possible to inform educated families that it is possible to make an early antenatal diagnosis on chorionic villus sampling at the tenth week of pregnancy. We report our experience on ten antenatal diagnosis that were made. Furthermore, we were able to study 48 families with a live child who had the disease, and were able to change the probability of another child being born with the gene. This approach makes it possible for us to change the risk for a couple of giving birth to an affected child. It is also possible to extend the indications for trophoblast analysis to parallel cases where the risk is less than 1 in 4.

Chorionic Villi Sampling↗
PubMed1988

[Molecular biology and mucoviscidosis. Brest experience in 1987].

The gene for cystic fibrosis is located on the long arm of chromosome 7 at 7q31. The close linkage between the disease locus and several DNA markers allowed a study of the DNA restriction polymorphism pattern in 30 Breton families. The frequency of the haplotypes indicated by the probes pJ 3.11, met H and met D was established reaching a 66.6% informativity for the families studies. The complete informativity of a family allows for detection of heterozygous brothers and sisters, uncles and aunts and for antenatal screening on trophoblast biopsies in case of further pregnancies.

Child↗