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)

We report on a generally useful, partially automated, human mutation detection method based upon printing moderate density oligonucleotide arrays using a biorobot on activated nylon membranes. The Beckman Biomek 2000 was adapted to this task through fabrication of aluminum membrane filter holders and the development of an addressable Tool Command Language (Tcl) program, which can be invoked through BioScript. During program execution, a robot arm is moved along the x, y, and z axes to expel liquid, without dripping, from disposable barrier pipette tips and then to touch the drops on preactivated membranes. Printed arrays consist of alternating rows of oligonucleotides containing normal and mutant sequences. Hybridization of biotin labeled polymerase chain reaction products derived from human patient genomic DNA samples are visualized using chemiluminescent or chromogenic indicators. This technique allows unequivocal genotyping of 32 mutations at the beta-thalassemia locus (11p15.5) and of 34 mutations and one polymorphism at the cystic fibrosis transconductance membrane regulator locus (7p35).
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PMID:Robot printing of reverse dot blot arrays for human mutation detection. 1168 2

The population of Quebec, Canada (7.3 million) contains approximately 6 million French Canadians; they are the descendants of approximately 8500 permanent French settlers who colonized Nouvelle France between 1608 and 1759. Their well-documented settlements, internal migrations, and natural increase over four centuries in relative isolation (geographic, linguistic, etc.) contain important evidence of social transmission of demographic behavior that contributed to effective family size and population structure. This history is reflected in at least 22 Mendelian diseases, occurring at unusually high prevalence in its subpopulations. Immigration of non-French persons during the past 250 years has given the Quebec population further inhomogeneity, which is apparent in allelic diversity at various loci. The histories of Quebec's subpopulations are, to a great extent, the histories of their alleles. Rare pathogenic alleles with high penetrance and associated haplotypes at 10 loci (CFTR, FAH, HBB, HEXA, LDLR, LPL, PAH, PABP2, PDDR, and SACS) are expressed in probands with cystic fibrosis, tyrosinemia, beta-thalassemia, Tay-Sachs, familial hypercholesterolemia, hyperchylomicronemia, PKU, oculopharyngeal muscular dystrophy, pseudo vitamin D deficiency rickets, and spastic ataxia of Charlevoix-Saguenay, respectively) reveal the interpopulation and intrapopulation genetic diversity of Quebec. Inbreeding does not explain the clustering and prevalence of these genetic diseases; genealogical reconstructions buttressed by molecular evidence point to founder effects and genetic drift in multiple instances. Genealogical estimates of historical meioses and analysis of linkage disequilibrium show that sectors of this young population are suitable for linkage disequilibrium mapping of rare alleles. How the population benefits from what is being learned about its structure and how its uniqueness could facilitate construction of a genomic map of linkage disequilibrium are discussed.
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PMID:Human genetics: lessons from Quebec populations. 1170 44

The first clinically applied preimplantation genetic diagnosis (PGD) was reported more than a decade ago and since then PGD has known an exponential growth. This first report described the use of PCR to sex embryos from couples at risk for X-linked diseases. Not surprisingly, in the first years, the development of PCR-based tests led to PGD for well-known monogenic diseases such as cystic fibrosis and thalassaemia. When fluorescent in-situ hybridization (FISH) was introduced it quickly replaced PCR-based methods, which had led to misdiagnoses, for sexing of embryos. FISH was also quickly introduced for aneuploidy screening, which has as its main aim the improvement of IVF results in patients with poor reproductive outcome, and later for PGD in translocation carriers. In this review, PGD for patients with a pre-existing genetic risk will be discussed, i.e. the monogenic diseases and the translocations, as well as different biopsy methods and promising new developments.
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PMID:Current concepts in preimplantation genetic diagnosis (PGD): a molecular biologist's view. 1186 37

The presence of maternal cells in fetal samples constitutes a serious potential source for prenatal misdiagnosis. Here we present our approach for detecting maternal cell contamination (MCC) at prenatal diagnosis for eight monogenic disorders (autosomal recessive: beta-thalassaemia, sickle-cell anaemia, cystic fibrosis, prelingual deafness; autosomal dominant: achondroplasia, Huntington disease, myotonic dystrophy, neurofibromatosis type I; X-linked: spinobulbar muscular atrophy). Our aim was to apply a simple and low-cost approach, which would easily and accurately provide information on the fetal tissue MCC status. MCC testing was applied to cases of recessive inheritance where the primary mutation screening of the fetus revealed the presence of the maternal mutation, to cases concerning dominant inheritance and to cases of multiple gestation. The potential presence of maternal cells was determined by the amplification of the 3'-HVR/APO B, D1S80, THO1 and VNTRI of vWf polymorphic loci, which have previously demonstrated high heterozygosity in Caucasians. Among 135 prenatal diagnoses, 44 finally needed to be tested for MCC (32.6%). MCC was detected in four cases, where DNA was isolated directly from chorionic villi samples (CVS), and in one case with DNA isolated directly from amniotic fluid (AF). In almost 90% of cases a simple test of one polymorphic locus provided sufficient information about MCC. The choice of the appropriate locus is therefore essential, while the simultaneous screening of both parents provides the means for distinguishing non-informative sites about MCC.
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PMID:A simple and effective approach for detecting maternal cell contamination in molecular prenatal diagnosis. 1200 Dec 1

Phenylbutyrate is used in humans for treating inborn errors of ureagenesis, certain forms of cancer, cystic fibrosis and thalassemia. The known metabolism of phenylbutyrate leads to phenylacetylglutamine, which is excreted in urine. We have identified phenylbutyrylglutamine as a new metabolite of phenylbutyrate in human plasma and urine. We describe the synthesis of phenylbutyrylglutamine and its assay by gas chromatography/mass spectrometry as a tert-butyldimethylsilyl or methyl derivative, using standards of [(2)H(5)]phenylbutyrylglutamine and phenylpropionylglutamine. After administration of phenylbutyrate to normal humans, the cumulative urinary excretion of phenylacetate, phenylbutyrate, phenylacetylglutamine and phenylbutyrylglutamine amounts to about half of the dose of phenylbutyrate. Thus, additional metabolites of phenylbutyrate are yet to be identified.
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PMID:Identification of phenylbutyrylglutamine, a new metabolite of phenylbutyrate metabolism in humans. 1211 40

It has been estimated that greater than 35% of all human genes undergo alternative splicing. The process of alternative splicing is highly regulated and disruption of a splicing pattern can produce splice variants that have different functions. Certain splice variants that are associated with induction of cell death, regulation of cellular proliferation and differentiation, cell signaling, and angiogenesis are present in a variety of cancers. Several of these cancer-related alternatively spliced genes will be discussed in this review. In addition, alternative splicing is associated with several genetic disorders such as beta-thalassemia, cystic fibrosis, and muscular dystrophy. Control of pre-mRNA splicing patterns with antisense oligonucleotides presents an attractive way to potentially treat and manage a variety of diseases. This review will discuss potential gene targets for antisense oligonucleotide induced modification of alternative splicing patterns. Furthermore, the chemistries and delivery strategies of antisense oligonucleotides will be discussed.
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PMID:Modification of alternative splicing by antisense oligonucleotides as a potential chemotherapy for cancer and other diseases. 1218 80

Genetics is an important area of focus for the preconception visit (Table 4). Folic acid should be recommended for all women. The genetic and pregnancy history should be evaluated for clues to a genetic disorder. Preconception screening and counseling are available for many diseases that are indicated in the family history. Screening may be offered for sickle cell anemia, thalassemia, Tay Sachs disease, and cystic fibrosis in the appropriate population groups. Older couples should be counseled about their increased risks for having complications during pregnancy and for having children with genetic disorders.
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PMID:Genetics issues in preconception health care. 1241 84

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

Reverse allele specific oligonucleotide assays provide a robust method for the molecular characterization of high-mutation spectrum disorders. Commercial test have been developed for human leukocyte antigens class I and class II regions of human chromosome 6, the cystic fibrosis transmembrane conductance regulator at 7q31 and strains of human Hepatitis B and C virus. In their most developed form, these assays rely upon highly multiplexed PCR reactions containing biotinylated primers providing a substrate for nonradioactive detection systems. Sophisticated reverse dot-blot technology involves mechanized covalent attachment of activated primary amine-conjugated oligonucleotides to carboxylated nylon membranes or bovine serum albumin. Subsequent to line or dot printing, membranes are stored or sold dry in preparation for hybridization. Circular spots or lines are visualized colorimetrically after hybridization through the use of streptavidin horseradish peroxidase incubation followed by development using tetramethylbenzidine and hydrogen peroxide, or via chemiluminescence after incubation with avidin alkaline phosphatase conjugate and a luminous substrate susceptible to enzyme activation, such as CSPD, followed by exposure to x-ray film. The entire procedure from blood specimen receipt to result usually requires less than 1 day. Because of the simplicity, speed, and generally high sensitivity and specificity, large numbers of individuals can be rapidly screened using this technology. Rapid turnaround is often required in prenatal diagnosis of cystic fibrosis, beta-thalassemia and hemoglobinopathies, giving this technology has special applicability in those genetic diseases. Commercial instruments are available which automate the hybridization and color development. In addition, scanning software can capture the probe reactivity pattern and interpret it in terms of a genotype.
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PMID:Origin and utility of the reverse dot-blot. 1264 92

We have applied a new method of genetic analysis, called 'minisequencing', to preimplantation genetic diagnosis (PGD) of monogenic disorders from single cells. This method involves computer-assisted mutation analysis, which allows exact base identity determination and computer-assisted visualization of the specific mutation(s), and thus facilitates data interpretation and management. Sequencing of the entire PCR product is unnecessary, yet the same qualitative characteristics of sequence analysis are maintained. The main benefit of the minisequencing strategy is the use of a mutation analysis protocol based on a common procedure, irrespective of the mutations involved. To evaluate the reliability of this method for subsequent application to PGD, we analysed PCR products from 887 blastomeres including 55 PGD cases of different genetic diseases, such as cystic fibrosis, beta-thalassaemia, sickle cell anaemia, haemophilia A, retinoblastoma, and spinal muscular atrophy. Minisequencing was found to be a useful technique in PGD analysis, due to its elevated sensitivity, automation, and easy data interpretation. The method was also efficient, providing interpretable results in 96.5% (856/887) of the blastomeres tested. Fifteen clinical pregnancies resulted from these PGD cases; conventional prenatal diagnosis confirmed all the PGD results, and 10 healthy babies have already been born. Its applicability to PGD could be helpful, particularly in cases in which the mutation(s) involved are difficult to assess by restriction analysis or other commonly used methods.
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PMID:The minisequencing method: an alternative strategy for preimplantation genetic diagnosis of single gene disorders. 1280 47


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