Search PubMed⌕ Search

Biomedical subjects

G Lucotte

Publications and source records attributed to G Lucotte.

At least 91 records · Page 5Linked to original sources
PubMed1994

Detection of serum hepatitis B virus using a nested polymerase chain reaction assay.

We described a nested polymerase chain reaction (PCR) assay to detect serum hepatitis B virus (HBV) DNA in patients. We compared the sensitivity of the PCR assay to that of slot-blot hybridization for detecting HBV DNA in serum and found that analysis by PCR provides a > 10(4) fold increase over the slot-blot assay. Most of the HBe Ag-positive patients were positive in PCR, and most of those being anti-HBe-positive were negative with this PCR assay.

Base Sequence↗
PubMed1994

Trinucleotide repeat elongation in the huntingtin gene in Huntington's disease patients from 85 French families. The French HD Research Group.

IT15 is a new gene encoding a protein named huntingtin; a polymorphic CAG repeat in the proposed open reading frame of IT15 has been characterized, and an elongation of this repeat has been correlated to Huntington's disease (HD). We have investigated the CAG repeat in the huntingtin gene in 85 unrelated French families with Huntington's disease. In 79 patients (from 60 families, where at least one HD DNA was available) we found repeat lengths of 37 to 100 units, in contrast to 11 to 35 CAG's on normal chromosomes. Comparison of repeat length and age at onset of disease symptoms in 71 individuals confirms an inverse correlation (r = -0.51 for p < 10(-4)) between the age at onset and the number of CAG repeat units.

Adult↗
PubMed1994

Reduced variability in Y-chromosome-specific haplotypes for some Central African populations.

Only 7 nonrare haplotypes concerning Y-chromosome-specific TaqI fragments recognized by DNA probes p49f and p49a were encountered in 433 individuals belonging to 7 populations living in central Africa. Most of the haplotypes (77.7%) are characterized by the allelic combination A1,C0,D0,F1,I1 (haplotype IV). The degree of variability displayed by these sequences is low in the African population studied, compared with Europeans, probably because of the recent common origin of the Bantu-speaking populations studied and the common practice of male polygamy in Africa.

Africa, Central↗
PubMed1994

Prenatal diagnosis for the unstable CTG repeat sequence in myotonic dystrophy: a retrospective study in a French family.

The results of DNA analysis for the unstable CTG repeat are reported in a french family of myotonic dystrophy. This retrospective study confirms results obtained previously with a linked DNA marker, using the CTG repeat DNA sequence in the same family. The demonstrated possibility of predicting phenotype as well as genotype in prenatal diagnosis is important for such a disorder, were subjects may be severely affected.

Adult↗
PubMed1993

Molecular analysis of juvenile Huntington disease: the major influence on (CAG)n repeat length is the sex of the affected parent.

Juvenile Huntington disease (HD), characterised by onset of symptoms before the age of 20 with rigidity and intellectual decline, is associated with a predominance of affected fathers. In order to investigate the molecular basis for the observed parental effect, we have analysed the CAG trinucleotide repeat within the HD gene in 42 juvenile onset cases from 34 families. A highly significant correlation was found between the repeat length and age of onset (r = -0.86, p < 10(-7) and it was determined that the sex of transmitting parent was the major influence on CAG expansion leading to earlier onset. Neither the size of the parental upper allele, the age of parent at conception of juvenile onset child, nor the grandparental sex conferred a significant effect upon expansion. Affected sib pair analysis of CAG repeat length, however, revealed a high correlation (r = 0.91, p < 10(-7). Furthermore, analysis of nuclear and extended families showed a familial predisposition to juvenile onset disease. This study demonstrates that the sex of transmitting parent is the major influence on trinucleotide expansion and clinical features in juvenile Huntington disease.

Adolescent↗
PubMed1993

DNA analysis of distinct populations suggests multiple origins for the mutation causing Huntington disease.

Results of association studies can be significantly biased if the ancestry of the control population is not similar to that of the affected population. One approach to overcome such a bias is to use distinct populations where controls and affected individuals are likely to be of similar descent. We have examined homogeneous populations of French, Danish and Swedish ancestry for nonrandom allelic association between Huntington disease (HD) and several markers previously shown to be in association with HD. No evidence for nonrandom allelic association between HD and these markers was shown in these populations. The demonstration of association in a United Kingdom (UK) sample of similar size, and lack of significant differences in allele frequencies between the French, Danish, Swedish and UK populations suggested that the absence of association was not predominantly a consequence of allele frequencies or sample size. To investigate further the number of potential HD chromosomes, DNA haplotypes were constructed for the Danish, French, Swedish and UK populations. The minimum of two HD haplotypes observed in each of the French, Danish and Swedish populations, compared to the one haplotype in the UK population of a similar size, is an important factor accounting for the absence of association between HD and the DNA markers in these populations. Furthermore, these data are in favour of multiple independent origins for the mutation causing HD.

Alleles↗
PubMed1993

A transthyretin variant (alanine 71) associated with familial amyloidotic polyneuropathy in a French family.

A transthyretin (TTR) mutation is described in a 44 year old French woman from Caen who presented at the age of 40 with neuropathy in all four extremities, diarrhoea, and orthostatic hypotension. Her father died with a similar syndrome including vitreous opacities. A nerve biopsy from the proband showed amyloid deposits which stained with anti-transthyretin. Direct genomic DNA sequencing of TTR exon 3 showed both thymine and cytosine in the position corresponding to the second base of codon 71. This codes for a variant alanine (GCG) as well as the normal valine (GTG), indicating that the proband is heterozygous for the substitution. Since this substitution does not result in the creation or abolition of a restriction endonuclease recognition site, a new technique (PCR-IMRA) was used to create an RFLP. Using a 24 bp nucleotide mutagenesis primer in the PCR reaction, a new NspBII site is created on amplification of the variant allele. With this method a 170 bp TTR exon 3 PCR product was generated for both the normal and the variant allele. On digestion of the PCR product with NspBII, DNA from a heterozygous subject showed both the 170 bp undigested product from the normal allele and a 146 bp digestion product from the variant allele. By PCR-IMRA, two of five children of the proband were positive for the variant allele. This non-radioactive technique gives a rapid method for testing subjects at risk for this mutation.

Adult↗
PubMed1993

Prenatal diagnosis of hereditary amyloidosis in a Portuguese family living in France.

Portuguese type amyloidosis is an autosomal dominant condition caused by a mutation in the transthyretin gene. This mutation can be detected directly by the presence of a restriction site for NsiI. We report here our first prenatal diagnosis for this condition performed by chorionic villus sampling, polymerase chain reaction, and restriction enzyme digestion.

Amyloid Neuropathies↗
PubMed1993

Y-chromosome-specific haplotype diversity in Ashkenazic and Sephardic Jews.

DNA samples from Ashkenazic and Sephardic Jews were studied with Y-chromosome-specific DNA probes p49f and p49a to screen for RFLPs and haplotypes. All 16 European haplotypes were found in Jews, but only 2 of them (VII and VIII) were widespread. Haplotype distributions in the two Jewish populations are similar, but haplotypes XI and XV are more frequent in the Ashkenazim and haplotypes IV and V are more frequent in the Sephardim, indicating their origins.

Adult↗
PubMed1993

A more detailed map of the cystic fibrosis mutation DF508 frequencies in Europe.

When analyzed by origin, the frequency of the DF508 mutation (the main cystic fibrosis mutation) varies between population groups. We show here that the frequency of the DF508 mutation varies among different populations, being higher in northwest Europeans than in southeast European populations. The map we have constructed covers 25 countries; isofrequency curves were calculated using an original method.

Cystic Fibrosis↗
PubMed1992

Mapping the whole human genome by fingerprinting yeast artificial chromosomes.

Physical mapping of the human genome has until now been envisioned through single chromosome strategies. We demonstrate that by using large insert yeast artificial chromosomes (YACs) a whole genome approach becomes feasible. YACs (22,000) of 810 kb mean size (5 genome equivalents) have been fingerprinted to obtain individual patterns of restriction fragments detected by a LINE-1 (L1) probe. More than 1000 contigs were assembled. Ten randomly chosen contigs were validated by metaphase chromosome fluorescence in situ hybridization, as well as by analyzing the inter-Alu PCR patterns of their constituent YACs. We estimate that 15% to 20% of the human genome, mainly the L1-rich regions, is already covered with contigs larger than 3 Mb.

Base Sequence↗
PubMed1992

Detection of Chlamydia trachomatis by use of polymerase chain reaction.

A polymerase chain reaction (PCR) assay was developed for detection of Chlamydia trachomatis DNA. One primer set was used, from the published sequence of the common C. trachomatis plasmid. Detection of amplified sequences was carried out by agarose gel electrophoresis. Analysis of 106 clinical samples tested by cell culture and PCR showed a sensitivity of 100% when PCR was compared with cell culture.

Base Sequence↗
PubMed1992

Y-chromosome-specific haplotypes of Jews detected by probes 49f and 49a.

A sample of Ashkenazic and Sephardic Jews has been studied with respect to haplotypes at the 49f-49a Y-specific DNA probes. Only seven haplotypes were found in Jews, three of them (VII, VIII, and XI) being the most widespread. Haplotype distribution in the European non-Jewish population is different.

DNA Probes↗