SEARCH · PubMed Health

Results for “Polymorphism, Restriction Fragment Length”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,027 records · Page 57Linked to original sources

PubMed2006

Comparative study between the Light Cycler and the PCR-restriction fragment length polymorphism in detecting factor V Leiden and factor II 20210G>A mutations.

OBJECTIVES: To test reproducibility, speed and cost of testing for factor V Leiden and FII 20210G>A in our practice. DESIGN AND METHODS: We compared conformity, reproducibility, speed and cost using the Light Cycler (LC) and PCR-RFLP. RESULTS: There was 100% conformity and reproducibility. LC was faster but 23% more expensive per sample. When equipment depreciation and patient expenses are added, LC testing becomes cheaper. CONCLUSION: In our practice, LC provides fast, reproducible and cost-effective results.

DNA Mutational Analysis↗

PubMed1990

New restriction fragment length polymorphism (probe E9) reveals the highest linkage disequilibrium in Italian CF patients.

We report that the allele distribution for RFLP's flanking the CF gene differs between patients with and without pancreatic insufficiency. The present study confirms this difference. In both classes the linkage disequilibrium (LD) is highest with the RFLP revealed by probe E9. The haplotype distribution identified by these RFLP's can be used for indirect carrier detection.

Cystic Fibrosis↗

PubMed1990

[Genetic carrier detection for the Wiskott-Aldrich syndrome using restriction fragment length polymorphism analysis].

The gene for the Wiskott-Aldrich syndrome, an X-linked immunodeficiency disease, has been mapped between the RFLP markers DXS7 and DXS14 on the short arm of the X-chromosome. Close linkage to these markers permits accurate carrier detection and prenatal diagnosis. In one family with WAS patients in two generations, RFLP analysis was applied to three women at risk. It could be determined with more than 98.5% accuracy that these women were not carriers.

Adult↗

PubMed1999

Molecular studies of Japanese patients with group A xeroderma pigmentosum using polymerase chain reaction and restriction fragment length polymorphism and nonradioactive single strand conformation polymorphism analyses.

Xeroderma pigmentosum is an autosomal recessive disease characterized by extreme sensitivity of the skin to ultraviolet light, which results in a high incidence of early skin cancer. We report here the molecular analysis of the xeroderma pigmentosum group A complementing genes of five Japanese patients with group A xeroderma pigmentosum and their families, by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis, and by PCR and non-radioactive single strand conformation polymorphism (SSCP) analysis using the Pharmacia PhastSystem. Four of the five patients were found to be homozygous for a known splicing mutation of intron 3. One patient was found to be heterozygous for the splicing mutation of intron 3 and a known nonsense mutation of exon 6. This nonradioactive PCR-SSCP technique was as useful for the molecular diagnosis of patients with group A xeroderma pigmentosum as was PCR-RFLP analysis.

Adolescent↗

PubMed1986

Carrier diagnosis of Duchenne muscular dystrophy using restriction fragment length polymorphisms.

Molecular probes that are tightly linked to and flank the Duchenne muscular dystrophy (DMD) locus, have been used to characterize DMD mutations and diagnose female carriers. Deletions within the Xp21 region were identified for 8 of 71 families studied. Using both DNA and CK studies, accurate (96 to 98%) carrier or noncarrier diagnoses were made for 51 of 75 females at risk in 24 families with a single affected male. DNA studies resulted in an alteration of predicted risk in 40% of the cases. Recombinant diagnostic methods are useful for carrier detection in families with one or more affected males.

Chromosome Deletion↗

PubMed1997

Polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) and electrophoretic assays for the mouse obese (Lepob) mutation.

Three polymerase chain reaction-based assays for the mouse Lepob mutation are described: Dde I site created by the C-->T transversion characterizing Lepob enables positive detection of the mutant allele; positive detection of the wild-type Lep allele is achieved by the use of primer sequence which introduces an A-->C substitution, creating an Msp I site in the normal allele; and an electrophoretic assay which positively identifies the heterozygote.

Amino Acid Sequence↗

PubMed1991

On the association of restriction fragment length polymorphisms across species boundaries.

We study the expected values of gametic-phase disequilibrium in both nuclear and cytonuclear systems in a finite population composed of reproductively isolated subpopulations. Random drift alone within each subpopulation will generate permanent overall non-zero gametic-phase disequilibrium in both a two-locus nuclear system and a cytonuclear system unless the population has an overall initial disequilibrium of zero. We derive formulae for the expected overall disequilibrium when mutation is involved and demonstrate that these values decay to zero at an extremely slow rate compared with the decay of the expected disequilibria within each subpopulation.

Animals↗

PubMed2000

Cloning of the spoT gene of "Candidatus Phlomobacter fragariae" and development of a PCR-restriction fragment length polymorphism assay for detection of the bacterium in insects.

Marginal chlorosis is a new disease of strawberry in which the uncultured phloem-restricted proteobacterium "Candidatus Phlomobacter fragariae" is involved. In order to identify the insect(s) vector(s) of this bacterium, homopteran insects have been captured. Because a PCR test based on the 16S rRNA gene (rDNA) applied to these insects was unable to discriminate between "P. fragariae" and other insect-associated proteobacteria, isolation of "P. fragariae" genes other than 16S rDNA was undertaken. Using comparative randomly amplified polymorphic DNAs, an amplicon was specifically amplified from "P. fragariae"-infected strawberry plants. It encodes part of a "P. fragariae" open reading frame sharing appreciable homology with the spoT gene from other proteobacteria. A spoT-based PCR test combined with restriction fragment length polymorphisms was developed and was able to distinguish "P. fragariae" from other insect bacteria. None of the many leafhoppers and psyllids captured during several years in and around infected strawberry fields was found to carry "P. fragariae." Interestingly however, the "P. fragariae" spoT sequence could be easily detected in whiteflies proliferating on "P. fragariae"-infected strawberry plants under confined greenhouse conditions but not on control whiteflies, indicating that these insects can become infected with the bacterium.

Animals↗

PubMed2001

Characterization of IS6110 restriction fragment length polymorphism patterns and mechanisms of antimicrobial resistance for multidrug-resistant isolates of Mycobacterium tuberculosis from a major reference hospital in Assiut, Egypt.

We evaluated 25 Mycobacterium tuberculosis isolates from patients at a major Egyptian reference hospital in Assiut, Egypt, who had been treated for at least 1 year for tuberculosis. Typing patterns (IS6110) were diverse, and multidrug resistance was found among 11 (44%) of the isolates. Mutations associated with antimicrobial drug resistance were found in rpoB, katG, rpsL, and embB in the resistant isolates.

Antitubercular Agents↗

PubMed1987

A new HindIII restriction fragment length polymorphism in the hemophilia A locus.

Using a fragment of the cDNA for human coagulation factor VIII as a hybridization probe, we have detected a new polymorphic HindIII site in intron 19 of the factor VIII gene. The frequency of the minor allele is 0.30. This polymorphism shows strong linkage disequilibrium with a previously described BclI polymorphism in intron 18.

Alleles↗

PubMed2003

Clarithromycin resistance among Helicobacter pylori strains isolated from children: prevalence and study of mechanism of resistance by PCR-restriction fragment length polymorphism analysis.

Clarithromycin and metronidazole resistance was 29.1 and 23.9%, respectively, in 96 Helicobacter pylori strains obtained from pediatric patients. No resistance to amoxicillin was observed. Resistance according to patients' ages to clarithromycin and metronidazole was 45.4 and 18.2% in 22 patients from 4 to 8 years old, 30.2 and 20.7% in 53 patients from 9 to 13 years old, and 9.5 and 38.1% in 21 patients from 14 to 18 years old, respectively. The A2143G mutation was the most prevalent (82.1%) among clarithromycin-resistant strains.

Anti-Bacterial Agents↗

PubMed1993

A new restriction fragment length polymorphism at the DXS101 locus allows carrier detection in a family with X linked agammaglobulinaemia.

The gene responsible for X linked agammaglobulinaemia (XLA) lies in Xq22 and has recently been identified as atk. DXS101 is a polymorphic locus which is closely linked to the disease locus. In this report we describe the identification, by pulsed field gel electrophoresis, of a new polymorphism at the DXS101 locus with a predicted heterozygosity of 4.9%. Despite this low value, we show how this polymorphism has been important in carrier status determination in a family with XLA where assessment was not possible by other means.

Agammaglobulinemia↗

PubMed1990

Modifications to improve the effectiveness of restriction fragment length polymorphism typing.

A streamlined and effective method for RFLP analysis of DNA has been developed. Southern transfers are accomplished by alkali blotting DNA onto positively charged nylon membranes. The prehybridization step has been eliminated. The hybridization solution is composed of three cost-effective reagents: 7% SDS, 10% PEG, and phosphate buffer. By using probes that hybridize to variable number of tandem repeat loci, and RFLP analysis of one to two micrograms of genomic DNA can be achieved within five working days under normal working hours. With longer autoradiographic exposures, as little as 20-100 ng of human genomic DNA is sufficient for analysis.

Buffers↗

PubMed1999

Photosynthetic bradyrhizobia from Aeschynomene spp. are specific to stem-nodulated species and form a separate 16S ribosomal DNA restriction fragment length polymorphism group.

We obtained nine bacterial isolates from root or collar nodules of the non-stem-nodulated Aeschynomene species A. elaphroxylon, A. uniflora, or A. schimperi and 69 root or stem nodule isolates from the stem-nodulated Aeschynomene species A. afraspera, A. ciliata, A. indica, A. nilotica, A. sensitiva, and A. tambacoundensis from various places in Senegal. These isolates, together with 45 previous isolates from various Aeschynomene species, were studied for host-specific nodulation within the genus Aeschynomene, also revisiting cross-inoculation groups described previously by D. Alazard (Appl. Environ. Microbiol. 50:732-734, 1985). The whole collection of Aeschynomene nodule isolates was screened for synthesis of photosynthetic pigments by spectrometry, high-pressure liquid chromatography, and thin-layer chromatography analyses. The presence of puf genes in photosynthetic Aeschynomene isolates was evidenced both by Southern hybridization with a Rhodobacter capsulatus photosynthetic gene probe and by DNA amplification with primers defined from photosynthetic genes. In addition, amplified 16S ribosomal DNA restriction analysis was performed on 45 Aeschynomene isolates, including strain BTAi1, and 19 reference strains from Bradyrhizobium japonicum, Bradyrhizobium elkanii, and other Bradyrhizobium sp. strains of uncertain taxonomic positions. The 16S rRNA gene sequence of the photosynthetic strain ORS278 (LMG 12187) was determined and compared to sequences from databases. Our main conclusion is that photosynthetic Aeschynomene nodule isolates share the ability to nodulate particular stem-nodulated species and form a separate subbranch on the Bradyrhizobium rRNA lineage, distinct from B. japonicum and B. elkanii.

Bradyrhizobium↗

PubMed1991

Restriction fragment length polymorphisms in the Apo B gene in relation to coronary heart disease in a southern Asian population.

We have examined DNA polymorphisms associated with the apolipoprotein B gene in 95 Sri Lankan males with ischaemic heart disease and 95 matched controls. For polymorphisms detected using the XbaI or MspI enzymes the allele frequency in Sri Lankans contrasted markedly from that in Caucasians. Overall, there was no significant association of any allele studied with coronary disease cases in this sample. There was, however, a significant difference observed between the XbaI allele frequency in normotriglyceridaemic or normocholesterolaemic CHD cases compared with the allele frequency in the controls.

Alleles↗

PubMed1994

[Analysis of the TSH receptor gene structure in Graves' disease by a restriction fragment length polymorphism (RFLP) study].

We examined the structure of the TSH receptor gene in thyroid disorders, particularly in Graves' disease by a RFLP study with a cloned human TSH receptor cDNA as a probe. Southern blot analysis indicated that the TSH receptor gene is a single copy gene in the human genome. Although RFLPs were not detected in peripheral blood cells and thyroid tissues in patient with Graves' disease, significant RFLPs were found in 2 of 6 patients with adenoma. We conclude that there are no major abnormalities in the structure of the TSH receptor gene in patients with Graves' disease, and that DNA from thyroid adenomas can have large insertions or deletions.

DNA↗

PubMed1997

Restriction fragment length polymorphism analysis shows that the hippuricase gene of Campylobacter jejuni is highly conserved.

A 1151-bp amplicon containing the hippuricase (hipO) gene was obtained from 118 strains of Campylobacter jejuni and double-digested with AluI and DdeI to give five different PCR-RFLP patterns. Most strains had the six-banded profile predicted from sequence data. Lack of polymorphisms within the hipO gene indicated it was highly conserved amongst strains of Camp.jejuni, and the RFLP analysis provided only low discrimination as an epidemiological typing method. Detection of hipO by PCR provided a useful test for confirmatory identification of Camp. jejuni.

Amidohydrolases↗

PubMed2001

Terminal-restriction fragment length polymorphism (T-RFLP) screening of a marine archaeal clone library to determine the different phylotypes.

T-RFLP clone characterization (screening) was optimized for a fast and basepair-accurate characterization of clones from marine Archaea collected from the Eastern Mediterranean Sea. Because of the high sensitivity of T-RFLP fingerprinting, a protocol was developed where 10 initial PCR cycles gave detectable terminal fragments from clones. Additionally, forward and reverse primers for PCR were individually labeled and detected simultaneously to assess the suitability of the forward and reverse fragments for T-RFLP screening. Based on independent restriction digests with the tetrameric restriction enzymes HhaI, RsaI and HaeIII to characterize the 49 archaeal clones in our library, the clones were grouped into 13 T-RFLP operational taxonomic units (OTUs). Reverse fragments generally gave less heterogeneous fragments in size. The accuracy of T-RFLP screening was evaluated by sequencing representative clones. Closely related clones ( approximately 97% similarity) could only be resolved with multiple restriction digests where forward and reverse fragments were included in the analysis. All fragments from the clone library were detected in the T-RFLP fingerprint from the complex archaeal community. We found representatives of marine group I, II and III Archaea. Thus, the recently discovered low abundant marine group III Archaea could be clearly differentiated from the other clones in our library and comprised a considerable fraction of the clone library ( approximately 12%). Therefore, our T-RFLP screening approach proved successful in characterizing novel archaeal sequences from the marine environment.

Archaea↗