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Results for “Polymorphism, Restriction Fragment Length”

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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↗

PubMed1993

A search for associations between major histocompatibility complex restriction fragment length polymorphism bands and resistance to Haemonchus contortus infection in sheep.

Polymorphic bands were detected within the DQB and DRB regions of the ovine major histocompatibility complex by probing TaqI digested DNA from three large sheep half-sib families derived from a highly resistant ram. All animals were phenotypically assessed for Haemonchus contortus resistance by faecal egg counts and associations with RFLP bands and haplotypes were estimated using mixed model, best linear unbiased prediction statistical methods. Although the highly resistant sire was homozygous at the MHC, no significant associations were found between any band or haplotype and faecal egg count.

Animals↗

PubMed1992

[Genetic differentiation of the Mongolian population. Comparative analysis of the geographic distribution of biochemical markers of genes and restriction fragment length polymorphism of nuclear DNA in the Mongolian population].

The geographical distribution of the gene frequencies from loci: Hp, Tf, Gc, Pi, AcP1, GLO1, EsD, 6-PGD, PGM1 and RFLP's of the nuclear DNA of the loci HBG-2 (HindIII), HBB (AvaII), ApoB (XbaI), D7S8 (PstI), LDLR (HincII) and AT-3 was analysed in the Mongolian population. These data revealed the homogeneity of 18 local groups in Mongolia and extremely low genetic differences measured by GST. There was no differences in the average GST values between protein markers and nuclear DNA markers.

Chromosome Mapping↗

PubMed1989

Genetic analysis of new restriction fragment length polymorphisms (RFLP) in the human IgH constant gene locus.

The human immunoglobulin heavy chain constant gene locus (IGHC) is polymorphic at both the protein (Gm and A2m allotypes) and the DNA level [RFLP for the gamma genes (IGHG), the switch mu region (IGHSM) and the switch alpha regions (IGHSA)]. The polymorphisms have been a valuable tool for assessment of the IGHC locus organization and a variety of population genetics and immunological investigations. In this study three new probes, identifying regions related to the IGHG (IGHPG and IGHSG) or IGHA (IGHAT) genes, have been employed to describe 11 different loci, 6 of which were polymorphic. Most of the polymorphisms are probably due to short insertions/deletions, particularly the SG regions, due to their repetitive structure. Ten loci were assigned to the IGHC region on the basis of known restriction maps, deletion mapping and association with mapped RFLP; the 11th, despite a striking sequence similarity with the IGHPG regions, could not be assigned to any known IGHC subregion. Analysis of these and previously known IGHG RFLP in a sample of 65 unrelated subjects plus 15 families allowed us to draw a genetic map, with particularly high resolution in the GP-G2-G4 genes region, revealing a marked discontinuity in the linkage disequilibrium values between pairs of adjacent loci.

Biological Evolution↗

PubMed2005

IS6110 restriction fragment length polymorphism of Mycobacterium tuberculosis isolates from an area of Casablanca, Morocco.

Using IS6110 RFLP, 61 isolates recovered from new cases of pulmonary tuberculosis (TB) were compared from September to December 1999 in Casablanca, Morocco, a city with a high incidence of TB. The majority of the isolates (92%) harboured 6-14 copies of IS6110. The minimal fraction of patients in groups of recently acquired infection is 13.1%. This preliminary study showed that IS6110 RFLP is a suitable method for finger-printing Mycobacterium tuberculosis in Casablanca. The unexpectedly low level of recent transmission of TB found in this study deserves further studies involving higher numbers of isolates recovered during a longer recruitment period.

Humans↗

PubMed1998

GPT genotyping by polymerase chain reaction and restriction fragment length polymorphism analysis.

Polymorphism of GPT was investigated in blood samples from 241 unrelated Japanese individuals by PCR-RFLP analysis. Three common types were identified which agreed with those obtained by starch gel electrophoresis. The allele frequencies were GPT*1 = 0.604 and GPT*2 = 0.396. The population data fitted the Hardy-Weinberg law. The PCR-RFLP patterns of GPT were also demonstrated in semen, and the types coincided with those in the corresponding blood. The present method permitted GPT genotyping in bloodstains and semen stains stored for 20 years. The GPT system determined by PCR-RFLP can still be a useful supplement in medicolegal individualization of biological stains.

DNA↗

PubMed1987

Use of restriction fragment length polymorphism analysis for detecting carriers of "fragile X" syndrome.

Recombinant DNA technology promises to play an increasingly important role in the future of medicine. Application of this technology to the study of human disease will help us to define and clarify the molecular pathology of many clinical disorders, provide new diagnostic tools and approaches, and, finally, will provide new therapeutic agents including gene-replacement therapy. We have begun to exploit these powerful new techniques to aid in the laboratory diagnosis of several genetic disorders for which reliable assays are currently not available, such as "Fragile X" syndrome.

Chromosome Banding↗

PubMed1993

Genetic study of hydatidiform moles by restriction fragment length polymorphisms (RFLPs) analysis.

Twenty three hydatidiform moles (HMs) were studied using the techniques of "RFLPs" employing a minisatellite deoxyribonucleic acid probe. Among the 23 HMs, 17 were homozygous types resulting from a duplicated haploid sperm, and two were heterozygous types resulting from fertilization two independent sperms (dispermy). It was revealed that the four histopathologically diagnosed complete HMs (CHMs) were partial HMs (PHMs) with one maternal and 2 paternal chromosome contribution (diandry) or two maternal and 1 paternal alleles (digyny). The locus specific minisatellite probes were useful in classifying CHM into heterozygous and homozygous types as well as in diagnosing PHM. One heterozygous (50%) and 5 homozygous (29.4%) CHMs, and one PHM (25%) progressed to persistent gestational trophoblastic disease (p > 0.5).

Autoradiography↗

PubMed1995

Ovarian carcinoma-associated TaqI restriction fragment length polymorphism in intron G of the progesterone receptor gene is due to an Alu sequence insertion.

Alu sequences, short, repetitive transposable DNA elements, are factors in a number of genetic diseases. We previously identified a germline TaqI RFLP, located in intron G of the human progesterone receptor gene, that showed an association with the incidence of sporadic ovarian carcinoma. Furthermore, the polymorphism was characterized as a small (approximately 300-bp) insertion that was inherited in a Mendelian fashion. Because of its insertional character, we named this polymorphism PROGINS. We report the identification of PROGINS as a 306-bp Alu element of the PV or HS-1 Alu subfamily.

Alleles↗

PubMed2005

Identification of brucella species and biotypes using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Brucellosis is a worldwide zoonosis causing reproductive failures in livestock and a severe multi-organ disease in humans. The genus Brucella is divided into seven species and various biotypes differing in pathogenicity and host specificity. Although Brucella spp. represent a highly homogenous group of bacteria, RFLPs of selected genes display sufficient polymorphism to distinguish Brucella species and biovars. PCR-RFLP analysis shows excellent typeability, reproducibility, stability, and epidemiological concordance. Consequently, PCR-RFLP assays of specific gene loci can serve as tools for diagnostic, epidemiological, taxonomic, and evolutionary studies. Various PCR-RFLPs used for the identification of Brucella species and biotypes are reviewed.

Bacterial Outer Membrane Proteins↗

PubMed1994

[Restrictive fragment length polymorphism analysis of gamma-crystallin in congenital cataract families].

Using gamma-crystallin gene probe P5G1, we investigated the RFLP in two large families of congenital cataracts and normal people, calculated the allelic gene frequency and defined the haplotypes by genetic linkage analysis. In accordance with foreign reports, TaqI/p5G1 detected 3 polymorphic sites, and the allelic gene frequency was close to that in foreign reports. However, foreign reports claimed that the haplotype P was linked to Coppock cataracts, but we did not find such linkage by haplotype analysis. The result suggests that not all the inherited cataracts are linked to gamma-crystallin gene, and the haplotype P should not be simply regarded as genetic marker in prenatal diagnosis.

Cataract↗

PubMedDate not supplied

[Use of molecular DNA probes in the diagnosis of mucoviscidosis-- analysis of restriction fragment length polymorphisms (RFLP) in 22 high-risk families].

The results of DNA analysis with the aid of specific molecular probes are discussed. DNA analysis involved 22 families of a high risk of cystic fibrosis. A significance of the obtained results in genetic counselling is also discussed. DNA analysis enabled detection or exclusion of cystic fibrosis gene carrier state in patient's relatives. DNA analysis proved fully informative in case of 17 families being a base to offer these families prenatal diagnosis of the disease in the I trimester of pregnancy, if such a family plans conception, and to accept this diagnostic technique.

Adolescent↗

PubMed1991

[Carrier detection of Glanzmann's thrombasthenia by Taq I restriction fragment length polymorphism of GPIIIa gene].

Glanzmann's thrombasthenia (GT) is an autosomal recessive bleeding disorder in which platelets fail to aggregate in second hemostasis due to qualitative and/or quantitative defect in their GPIIb/IIIa complex. In the present study, both phenotypic and genotypic assays were performed by Western blot and Southern blot techniques in 13 members of 3 GT families. 2 GT carriers of 3 probable carriers whose clinical features and GPIIb/IIIa protein were essentially normal were determined by Taq I/5' GPIIIa RFLP. There were no major deletion or insertion in GPIIIa gene in 4 patients with GT. Thus, the genetic defects in these patients is most likely due to a small change or point mutation in the nucleotide sequence of GPIIIa coding region.

Adolescent↗

PubMedDate not supplied

IgA2 allotypes determined by restriction fragment length polymorphism in IgA deficiency. Re-expression of the silent A2m(2) allotype in the children of IgA-deficient patients.

IgA2 allotyping was performed on DNA from 60 IgA-deficient Caucasian individuals. The frequency of A2m(2) was not statistically different from that of normal controls. Two informative families were selected for further studies. In both families, the A2m(2) allotype (derived from the IgA-deficient parent) was inherited by some of the children, as determined by Southern blotting experiments. In all cases the 'silent' IgA2m2 gene was re-expressed, as judged by conventional serological allotyping of serum proteins. These data strongly argue against structural gene deletions or mutations as a cause of IgA deficiency.

Alleles↗

PubMed1992

The NM23 gene maps to human chromosome band 17q22 and shows a restriction fragment length polymorphism with BglII.

The NM23-Hl gene is a putative tumor suppressor gene that may be important in the metastasic process. Recent genetic and immunological data indicate that the NM23-Hl gene encodes a protein with nucleoside diphosphate (NDP) kinase activity. The mapping of NM23-Hl by panels of rodent-human somatic cell hybrids and in situ hybridization showed that the gene is located in human chromosome band 17q22. A two-allele polymorphism with BglII was demonstrated.

Alleles↗