Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The haploid nucleus of a human cell contains 3 X 10(9) base pairs. Organized in linear duplex, this DNA would stretch out to a length of some 90 cm. Thus, organization of chromosomes has been a major subject for pioneer cytogenetists. Long lasting controversies on the strandedness of chromosomes, together with newly developed banding techniques, led us to molecular cytogenetics. Next, the discovery of reverse transcriptase, restriction endonucleases, and other recombinant DNA methods have enabled us to isolate and characterize genes from any organism and to determine the DNA sequences and any encoded protein sequences. These new technologies have already helped us to understand many inherited diseases at a molecular level. In sickle cell anemia, thalassemia and in other mendelian disorders we can know their molecular defects by examining the DNA from peripheral leukocytes, without the need for complex biochemical assays or biopsies. Southern blot analysis using restriction endonuclease and a probe is a basic tool for molecular diagnosis. cDNA or DNA fragments are used as probes. Recently, synthesized oligonucleotide probes are available, if the DNA sequence of a gene is determined. In addition, restriction fragment length polymorphisms (RFLPs), play a very important role in the molecular diagnosis. Linkage analysis using RFLPs linked to the gene locus of a certain disease also permits the detection of the patients and carriers within families with genetic diseases of unknown cause. Starting with the genetic map and physical map, genes for cystic fibrosis and Duchenne muscular dystrophy have recently been isolated and cloned.
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PMID:[Recent advances in human molecular genetics]. 197 24

In 1989 we are continuing to move gene diagnosis over to the direct detection mode. We have sickle cell anemia, alpha-thalassemia, beta-thalassemia, Duchenne muscular dystrophy, Becker muscular dystrophy and cystic fibrosis moved to direct detection with hemophilia B and alpha-1-antitrypsin deficiency soon to be there. For indirect detection, we still have hemophilia A, and a comment on the genetics of hemophilia A is important. Remember that sickle cell anemia is caused by one mutation, while beta-thalassemia and cystic fibrosis have a finite number of alleles. Duchenne muscular dystrophy results from a different mutation for every affected individual, but most of these are deletions and can be directly detected. Hemophilia A is another X-linked disorder with almost every affected individual having a different mutation. That means that there probably are 100 ways to get beta-thalassemia and about 10,000 ways to get hemophilia A, so we need some really good novel techniques to detect these directly, and we are working hard on such techniques. I would not be surprised if hemophilia A moved into the direct detection category in the next year or so. We need to find the Huntington disease gene, and then it will move into the direct detection column. Neurofibromatosis is still in the indirect detection group but also may move very soon. Polycystic kidney disease is also still in the indirect detection column. This summarizes where prenatal and presymptomatic gene diagnosis stands in late 1989.
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PMID:Current status of prenatal diagnosis by DNA analysis. 209 48

Using the recent developments of molecular biology techniques, our laboratory is offering carrier and prenatal diagnosis for a variety of genetic disorders including cystic fibrosis, phenylketonuria, thalassaemia alpha and beta, sickle cell anaemia, myotonic dystrophy, von Recklinghausen's disease, autosomal polycystic kidney disease, haemophilia A and B, Martin-Bell syndrome (fragile X), Becker and Duchenne muscular dystrophy, etc. It is likely that the rapid advances made in the establishment of the human genetic map will considerably expand the spectrum of diseases for which diagnosis by molecular genetics will become available.
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PMID:[Molecular and diagnostic genetics]. 219 51

The current state of molecular diagnosis of some common genetic diseases, including cystic fibrosis, Duchenne muscular dystrophy, haemophilia A and B, phenylketonuria, and thalassaemia, in Russia and elsewhere in the former USSR is reviewed. Data on carrier detection and prenatal diagnosis are presented and some objective problems and obstacles hampering efficient molecular diagnosis in Russia are discussed. The necessity for molecular diagnosis of some other inherited diseases (for example, von Willebrand's disease, Martin-Bell syndrome, polycystic kidney disease, Huntington's disease, and myotonic dystrophy) is stressed. The need for establishing new diagnostic centres dealing with the most common diseases, as well as rare genetic diseases, is substantiated. Perspectives on the implementation of new molecular methods and new technical approaches (preimplantation embryo diagnosis, fetal cells selected from maternal blood) are briefly outlined.
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PMID:Molecular diagnosis of some common genetic diseases in Russia and the former USSR: present and future. 844 19

Unusually high levels of fetal haemoglobin production can ameliorate sickle cell disease and beta thalassaemia. Although efforts directed at the pharmacological stimulation of fetal haemoglobin as an approach to managing these conditions have met with limited success, there is wide variation in individual responses. Whether this reflects the particular mutations that underlie these conditions or other genetic factors remains to be determined, as does the ideal combination of agents to achieve this end. These results are encouraging, however, in particular in view of the recent demonstration that other monogenic diseases, Duchenne muscular dystrophy, for example, might be amenable to the same therapeutic strategy.
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PMID:The therapeutic reactivation of fetal haemoglobin. 973 88

Using the new DNA technology, it is now possible to offer prenatal diagnosis or presymptomatic testing for many genetic diseases. For prenatal diagnosis, foetal tissue is obtained by chorionic villus sampling at 9 to 11 weeks gestation or amniocentesis at 18 weeks. The programme in Hong Kong, which started in 1982, is reviewed here and now included alpha and beta thalassaemia, haemophilia A and B, Duchenne muscular dystrophy, Huntington's diseases, and spinal muscular atrophy. DNA diagnosis can now be performed using a single cell obtained from pre-implantation embryos or from rare foetal cells isolated from maternal peripheral blood. The latter is safer and more acceptable to parents. Presymptomatic testing for untreatable diseases such as Hungtington's disease poses new ethical and social problems that need to be resolved. As many more genes are being discovered, prenatal diagnosis and presymptomatic testing programmes will continue to meet new challenges in the future.
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PMID:Prenatal diagnosis of common single gene disorders by DNA technology. 1185 May 68

Fetal cells and cell-free fetal DNA can be found circulating in maternal blood. Fetal cells recovered from maternal blood provide the only source of pure fetal DNA for noninvasive prenatal DNA diagnosis. Fetal nucleated erythrocytes (NRBCs) are considered the most suitable maternally-circulating fetal cells for this purpose, because they are not commonly found in the peripheral blood of healthy adults and are most abundant in the fetus during early gestation. Because fetal cells in maternal blood are extremely rare, a definitive separation method has not yet been established. Fetal NRBCs can be enriched from maternal blood via fluorescence- or magnetic-activated cell sorting, density gradients, immuno-magnetic beads or micromanipulation. Fetal cells are identified by Giemsa staining, hybridization with Y-chromosome specific probes, PCR-detection of a specific paternal allele, or immunostaining for fetal cell antigens. Amplification of fetal DNA sequences by primer extension preamplification and PCR has allowed prenatal screening for Duchenne muscular dystrophy and the fetal RhD blood type. Sequence-specific hybridization has been used to detect sickle cell anemia and beta-thalassemia prenatally in heterozygous carriers of these disorders. The use of cell-free fetal DNA in maternal plasma for the diagnosis of single-gene disorders is limited to disorders caused by a paternally inherited gene or a mutation that can be distinguished from the maternally inherited counterpart. At present, fetal gender can be determined from maternal plasma. When a pregnant woman is a heterzygous carrier of an X-linked disorder, the determination of fetal gender is clinically very informative for first-step screening to avoid invasive amniocentesis. The non-invasive prenatal diagnosis of genetic disorders should be applied to pregnant women with a definite risk for a specific single-gene disorder.
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PMID:Prenatal screening of single-gene disorders from maternal blood. 1217 72

OBJECTIVE: To investigate the feasibility of multiple loci detection in single cell by primer extension preamplification (PEP) followed by nest PCR. METHODS: Using PEP, the whole genomic DNA in single lymphocyte or single blastomere was amplified. In addition, CD17, nt-28 and linked ATTTT repeat for beta-thalassemia, F508 and linked GATT repeat for cystic fibrosis, DMD exon 17 and 48 for Duchenne muscular dystrophy, short tandem repeats of D18S51, D21S11 and D21S1411, and sex-determination gene SRY of the Y chromosome were all detected using nest-PCR from a small aliquot of the PEP reaction. RESULTS: The rate of successful single lymphocyte amplification was 89.5%(false positive 0.48%false negative 2.5%). The rate of successful single blastomere amplification was 85.56%(false positive 3%). CONCLUSION: The PEP technique followed by nest PCR analysis of single cell is very useful for simultaneous detection of multiple gene loci. It may be applicable for preimplantation genetic diagnosis.
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PMID:[Detection of multiple loci in single cell by primer extension preamplification and nest PCR] 1259 99

The frequency, distribution pattern and localisation of gamma radiation-induced break points on the chromosomes of patients with various inherited metabolic disorders were studied to detect: (i) whether the break point distribution following irradiation is random and proportional to the length or the DNA content of the chromosome, or non-proportionally distributed on their length and at times clustering to form hot spots on certain region of the chromosomes; and (ii) to find whether there exists a syndrome-related chromosome-specific pattern of radiation-induced break points. Lymphocyte cultures from patients of haemophilia, ichthyosis, Duchenne muscular dystrophy, retinitis pigmentosa and alpha-thalassemia, whose defective gene loci were located by DNA probe method, were subjected to 3Gy of gamma radiation at G(0). The chromosomal break point analysis was carried out on all the 23 types of chromosomes (excluding Y chromosome) using G banding and FISH painting. The exact location of the break points on G-banded chromosomes was identified using a semi-automated microscope densitometer system (Leitz MPV2). In normal individuals in all the chromosomes except the chromosome 1, a random distribution of break points proportional to their length based on their DNA content was observed. However, in all the syndromes studied a mixture of hypersensitive chromosomes with a non-random distribution pattern of chromosomal break points invariably clustering to form hot spots, and chromosomes with random distribution of break points proportional to their length were observed. The hypersensitive chromosomes and their hot spots were syndrome-specific.
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PMID:Syndrome-related chromosome-specific radiation-induced break points of various inherited human metabolic disorders. 1283 62

Small DNA fragments have been used to modify endogenous genomic DNA in both human and mouse cells. This strategy for sequence-specific modification or genomic editing, known as small-fragment homologous replacement (SFHR), has yet to be characterized in terms of its underlying mechanisms. Genotypic and phenotypic analyses following SFHR have shown specific modification of disease-causing genetic loci associated with cystic fibrosis, beta-thalassemia, and Duchenne muscular dystrophy, suggesting that SFHR has potential as a therapeutic modality for the treatment of monogenic inherited disease.
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PMID:Sequence-specific modification of genomic DNA by small DNA fragments. 1295 8


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