| 1. |
- Hietala, M, et al.
(författare)
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DNA-based carrier screening in primary healthcare : screening for aspartylglucosaminuria mutations in maternity health offices
- 1996
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Ingår i: Clinical Chemistry. - 0009-9147 .- 1530-8561. ; 42:9, s. 1398-1404
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Tidskriftsartikel (refereegranskat)abstract
- Large-scale genetic screening programs are complex enterprises in which ethical, technical, medical, and socioeconomic aspects have to be handled with professional expertise. Establishment of automated, relatively robust, and inexpensive laboratory techniques is one step of this path. Here a pilot carrier-screening program for the mutations causing aspartylglucosaminuria was carried out for pregnant women in primary care maternity health offices. Women (1975) were tested before their 12th week of pregnancy, and 31 heterozygotes were detected. The sampling was based on dried blood strips, facilitating convenient handling and inexpensive mailing to the laboratory. The mutation detection technique, solid-phase mini-sequencing simplified by the use of scintillation microplates and automated equipment, proved to be rapid, simple, inexpensive, and reliable, with a low repeat rate (2.5%). In conclusion, we found that good collaboration between the primary healthcare unit, the laboratory, and counseling experts, combined with modern laboratory technology, facilitate reliable low-cost genetic testing.
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| 2. |
- Järvelä, I, et al.
(författare)
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Rapid diagnostic test for the major mutation underlying Batten disease
- 1996
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Ingår i: Journal of Medical Genetics. - 0022-2593 .- 1468-6244. ; 33:12, s. 1041-1042
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Tidskriftsartikel (refereegranskat)abstract
- Batten disease is the most common progressive neurodegenerative disorder of childhood in western countries. A novel cDNA responsible for Batten disease has recently been identified. We have developed a rapid diagnostic solid phase minisequencing test to detect the major 1.02 kb deletion which is responsible for 81% of affected chromosomes in Batten disease worldwide. In Finland, 90% of Batten chromosomes carry the major deletion owing to the enrichment of the CLN3 gene in the isolated Finnish population.
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| 3. |
- Karttunen, L, et al.
(författare)
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An accurate method for comparing transcript levels of two alleles or highly homologous genes : application to fibrillin transcripts in Marfan patients' fibroblasts
- 1996
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 6:5, s. 392-403
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Tidskriftsartikel (refereegranskat)abstract
- We introduce here a novel and generally applicable, solid-phase minisequencing-based approach for rapid estimation of relative levels of transcripts with high sequence homology. This study was undertaken to screen for the consequences of different fibrillin-1 mutations on the transcript levels in patients with the Marfan syndrome (MFS). This dominantly inherited, connective tissue disorder is characterized by pleiotrophic symptoms in cardiovascular, skeletal, and ocular systems. A spectrum of disease mutations in the gene encoding fibrillin-1 (FBN1), a glycoprotein component of extracellular matrix microfibrils, has been identified in MFS patients, but the mechanisms by which mutations result in different phenotypic manifestations are still unknown to a large extent. Our data from the quantitation of FBN1 transcripts provide support for the hypothesis that mutations causing premature stop codons result in a milder phenotype than classical MFS by reducing the stability of the mutant transcript and, consequently, decreasing the interference of mutant polypeptide in the formation of fibrillin fibers. We also applied this mRNA quantitation method to determine the relative ratio between transcripts from the genes coding for two highly homologous microfibrillar components, FBN1 and FBN2, in control fibroblast cultures as well as in fibroblasts from MFS patients. Interestingly, these data show large variations between the levels of the two transcripts in fibroblast cultures, but these variations do not correlate either with the nature of the disease mutation or to the clinical MFS phenotype.
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| 4. |
- Laan, M, et al.
(författare)
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Solid-phase minisequencing confirmed by FISH analysis in determination of gene copy number
- 1995
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Ingår i: Human Genetics. - 0340-6717 .- 1432-1203. ; 96:3, s. 275-280
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Tidskriftsartikel (refereegranskat)abstract
- The solid-phase minisequencing method (Syvnen et al. 1990) allows accurate quantative determination of the ratio between two DNA or RNA sequences that are present as a mixture in a sample and differ from each other only by a single nucleotide. Here, we present another application of the minisequencing method, the determination of the gene copy number in a genome. The copy number of a marker gene aspartyl glucosaminidase (AGA) located at 4qter, was determined in three patients with a chromosomal alteration involving the distal region of 4q. For the minisequencing assay an equal amount of DNA from a patient homozygous for a mutation in the AGA gene was added to the DNA samples concerned. The relative amount of the normal sequence determined in each combined sample gives the copy number of the AGA gene. Fluorescence in situ hybridization (FISH), applied in parallel as a control, produced concordant results with solid-phase minisequencing in each case. As the potential of the minisequencing lies in automation, it could be a useful tool in the screening of monosomies, trisomies or loss of heterozygosity in diagnostics.
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| 5. |
- Pastinen, T, et al.
(författare)
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Minisequencing : a specific tool for DNA analysis and diagnostics on oligonucleotide arrays
- 1997
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 7:6, s. 606-614
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Tidskriftsartikel (refereegranskat)abstract
- We describe a method for multiplex detection of mutations in which the solid-phase minisequencing principle is applied to an oligonucleotide array format. The mutations are detected by extending immobilized primers that anneal to their template sequences immediately adjacent to the mutant nucleotide positions with single labeled dideoxynucleoside triphosphates using a DNA polymerase. The arrays were prepared by coupling one primer per mutation to be detected on a small glass area. Genomic fragments spanning nine disease mutations, which were selected as targets for the assay, were amplified in multiplex PCR reactions and used as templates for the minisequencing reactions on the primer array. The genotypes of homozygous and heterozygous genomic DNA samples were unequivocally defined at each analyzed nucleotide position by the highly specific primer extension reaction. In a comparison to hybridization with immobilized allele-specific probes in the same assay format, the power of discrimination between homozygous and heterozygous genotypes was one order of magnitude higher using the minisequencing method. Therefore, single-nucleotide primer extension is a promising principle for future high-throughput mutation detection and genotyping using high density DNA-chip technology.
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| 6. |
- Pastinen, T, et al.
(författare)
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Multiplex, fluorescent, solid-phase minisequencing for efficient screening of DNA sequence variation
- 1996
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Ingår i: Clinical Chemistry. - 0009-9147 .- 1530-8561. ; 42:9, s. 1391-1397
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Tidskriftsartikel (refereegranskat)abstract
- We developed a multiplex, solid-phase minisequencing method to detect multiple single-nucleotide polymorphisms in an undivided sample. The amplified DNA templates are first captured on a manifold. Then, with multiple minisequencing primers of various sizes, single-nucleotide extension reactions are carried out simultaneously with fluorescently labeled dideoxynucleotides. The size of the extended product, determined by using a DNA sequencing instrument, defines the site of the polymorphisms, and the incorporated nucleotide gives the identity of the nucleotide at each site. HLA-DQA1 typing was used as a model system to evaluate the method. The DR2 subgroup of the HLA-DRB1 gene was typed along with the DQA1 gene to demonstrate the feasibility of the method in analyzing multiple genes at multiple sites simultaneously. The method is generally applicable for screening any single-nucleotide polymorphisms or point mutations, and its manifold format allows practical handling of large numbers of samples.
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| 7. |
- Paunio, T, et al.
(författare)
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Preimplantation diagnosis by whole-genome amplification, PCR amplification, and solid-phase minisequencing of blastomere DNA
- 1996
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Ingår i: Clinical Chemistry. - 0009-9147 .- 1530-8561. ; 42:9, s. 1382-1390
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a new method for preimplantation diagnosis of inherited diseases. Our procedure for the identification of point mutations in single cells combines whole-genome amplification using 15-mer random primers (primer extension preamplification, PEP) with a single locus-specific PCR amplification, followed by detection of the mutation by solid-phase minisequencing. The procedure was evaluated by detecting three disease-causing mutations and seven polymorphic nucleotides located on different human chromosomes from single granuloma and blastomere cells. The correct genotype of the cell was identified at 96% of the nucleotide positions analyzed, showing that a representative part of the genome is amplified during PEP. We estimate that PEP yielded at least 1000 copies of the genome. The quantitative nature of the solid-phase minisequencing method allowed us to notice that preferential amplification of one allele occurs at heterozygous loci during PEP, which is a potential problem in preimplantation diagnosis.
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| 8. |
- Paunio, T, et al.
(författare)
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Tissue distribution and levels of gelsolin mRNA in normal individuals and patients with gelsolin-related amyloidosis.
- 1997
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Ingår i: FEBS Letters. - 0014-5793 .- 1873-3468. ; 406:1-2, s. 49-55
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Tidskriftsartikel (refereegranskat)abstract
- We measured quantitatively the mRNA levels of intracellular and secretory forms of gelsolin, an actin-modulating protein, in human tissues from subjects of different ages. The intracellular gelsolin mRNA constituted the major type of gelsolin steady-state mRNA in all tissues analyzed. Both forms of gelsolin were expressed in most adult tissues, with particularly high mRNA levels in all types of muscle and interestingly in skin. Between the adult and infantile tissues the most striking difference in expression levels was found in liver, as the adult liver contained only a subtle amount of gelsolin mRNA. Skin and muscle samples from patients with gelsolin-related amyloidosis (FAF), with significantly increased concentrations of serum gelsolin, did not reveal an increased expression of the gene, and both mutant and wild-type alleles were expressed in equal amounts. The high level of expression of the gelsolin gene in the skin in general could locally contribute to the characteristic skin amyloidosis in FAF patients.
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| 9. |
- Sitbon, G, et al.
(författare)
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A colorimetric minisequencing assay for the mutation in codon 506 of the coagulation factor V gene
- 1997
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Ingår i: Thrombosis and Haemostasis. - 0340-6245 .- 2567-689X. ; 77:4, s. 701-703
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Tidskriftsartikel (refereegranskat)abstract
- We describe a colorimetric screening method for the mutation in codon 506 of the coagulation factor V gene. The nucleotide at the site of the FV:Q506 mutation is identified in an immobilized amplified DNA template by extension of a primer with a hapten-labelled dNTP using a DNA polymerase. The incorporated hapten is detected by an antibody-alkaline phosphatase conjugate that catalyses the formation of a coloured end product. The assay is carried out in a microtiter plate format, and the procedure is identical to that of enzyme immunoassays. It unequivocally identifies the FV:Q506 mutation in heterozygous and homozygous form. The colorimetric minisequencing method gave the same result as a 3H-based minisequencing assay and restriction site analysis with Mn11 used as reference methods. Because of its simple format and numeric result, the novel colorimetric minisequencing method should be an attractive alternative for screening for the FV:Q506 mutation in clinical laboratories.
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| 10. |
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