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M Goossens

Publications and source records attributed to M Goossens.

At least 181 records · Page 10Linked to original sources
PubMed1989

Mutations in the catalytic domain of human coagulation factor IX: rapid characterization by direct genomic sequencing of DNA fragments displaying an altered melting behavior.

Deficiency in coagulation factor IX, a plasma glycoprotein constituent of the clotting cascade, results in hemophilia B, an inherited recessive X-linked bleeding disorder. Some affected individuals, referred to as antigen positive or CRM+, express an inactive factor IX gene product at normal levels and are expected to have natural mutations altering domains of the molecule that are critical for its correct function. The serine protease catalytic domain of activated factor IX, encoded by exons VII and VIII of the gene, is a possible target for such mutations. We designed a strategy allowing rapid analysis of this region through enzymatic amplification of genomic DNA, analysis of the amplification products by denaturing gradient gel electrophoresis, and direct sequencing of the fragments displaying an altered melting behavior. This procedure permitted us to characterize two previously undescribed mutations. Factor IX Angers is a G-to-A substitution generating an Arg in place of a Gly at amino acid 396 of the mature factor IX protein. Factor IX Bordeaux is an A-to-T substitution introducing a nonsense codon in place of the normal codon for Lys at position 411. Moreover, the already described factor IX Vancouver defect was found in three apparently independent families. These results provide further insight into the molecular heterogeneity of hemophilia B. In addition, we demonstrate the usefulness of this rapid screening procedure, which has broad applications in human genetics and can be used as an alternative to RFLP analysis in carrier detection or prenatal diagnosis studies.

Base Sequence↗
PubMed1989

Tissue-specific splicing mutation in acute intermittent porphyria.

An inherited deficiency of porphobilinogen deaminase [porphobilinogen ammonia-lyase (polymerizing), EC 4.3.1.8] in humans is responsible for the autosomal dominant disease acute intermittent porphyria. Different classes of mutations have been described at the protein level suggesting that this is a heterogeneous disease. It was previously demonstrated that porphobilinogen deaminase is encoded by two distinct mRNA species expressed in a tissue-specific manner. Analysis of the genomic sequences indicated that these two mRNAs are transcribed from two promoters and only differ in their first exon. The first mutation identified in the human porphobilinogen deaminase gene is a single-base substitution (G----A) in the canonical 5' splice donor site of intron 1. This mutation leads to a particular subtype of acute intermittent porphyria characterized by the restriction of the enzymatic defect to nonerythropoietic tissues. Hybridization analysis using oligonucleotide probes after in vitro amplification of genomic DNA offers another possibility of detecting asymptomatic carriers of the mutation in affected families.

Acute Disease↗
PubMed1989

A 5' splice-region G----C mutation in exon 1 of the human beta-globin gene inhibits pre-mRNA splicing: a mechanism for beta+-thalassemia.

We have characterized a Mediterranean beta-thalassemia allele containing a sequence change at codon 30 that alters both beta-globin pre-mRNA splicing and the structure of the hemoglobin product. Presumably, this G----C transversion at position -1 of intron 1 reduces severely the utilization of the normal 5' splice site since the level of the Arg----Thr mutant hemoglobin (designated hemoglobin Kairouan) found in the erythrocytes of the patient is very low (2% of total hemoglobin). Since no natural mutations of the guanine located at position -1 of the CAG/GTAAGT consensus sequence had been isolated previously, we investigated the role of this nucleotide in the constitution of an active 5' splice site by studying the splicing of the pre-mRNA in cell-free extracts. We demonstrate that correct splicing of the mutant pre-mRNA is 98% inhibited. Our results provide further insights into the mechanisms of pre-mRNA maturation by revealing that the last residue of the exon plays a role at least equivalent to that of the intron residue at position +5.

Adult↗
PubMed1989

Molecular analysis of acute intermittent porphyria in a Finnish family with normal erythrocyte porphobilinogen deaminase.

Porphobilinogen deaminase, the third enzyme of the haem biosynthetic pathway, is encoded by two distinct mRNA species expressed in a tissue-specific manner from a single gene. These two mRNAs are transcribed from two promoters and only differ in their first exon. An inherited deficiency or porphobilinogen deaminase in man is responsible for the autosomal dominant disease acute intermittent porphyria. Different classes of mutations have been described at the protein level suggesting that this is a heterogeneous disease. In the present report, we describe the molecular abnormality responsible for a variant form of acute intermittent porphyria where the enzyme defect is restricted to non-erythroid cells. Upon cloning and sequencing the mutant allele of a patient from a large Finnish kindred, a single-base substitution within the 5'-splice donor sequence of intron 1 was found at the last position of exon 1 (CG----CT). The identification of this mutation allowed us to detect asymptomatic gene carriers among family members using in vitro amplification of DNA and hybridization of the target sequence to allele-specific oligonucleotides.

Ammonia-Lyases↗
PubMed1989

Posterior subtalar joint arthrography. A useful tool in the diagnosis of hindfoot disorders.

Obscure hindfoot disorders are often classified under the heading of sinus tarsi syndrome (STS). The diagnosis of STS is based upon subjective symptoms: tenderness over the lateral aperture of the sinus tarsi and hindfoot instability. Arthrography of the posterior subtalar joint is an objective parameter, identifying peri- or intraarticular pathology as the cause of symptoms. In 27 patients with STS, the pathologic arthrographic findings include less-marked microrecesses in the sinus tarsi region, ganglions at the anterior aspect of the subtalar joint, retraction of the joint recesses, a smooth and rounded appearance of the capsule, and a frozen subtalar joint. Through analysis of these films, the appropriate therapeutic approach can be outlined; infiltrations into the sinus tarsi itself, intraarticular corticosteroid injections, or subtalar arthrodesis for resistant cases are the procedures of choice. In the authors' experience, surgical curettage of the sinus tarsi has no place in the treatment of STS.

Adolescent↗
PubMed1989

A new system to produce intraoperatively custom femoral prosthesis from measurements taken during the surgical procedure.

A system has been developed that allows the surgeon to match a prosthesis to any femoral cavity. The surgeon may choose how and where it will preferentially fit. The surgeon does not have to create a cavity to suit a premade prosthesis. The system is based on a novel technique for making a mold of the prepared femoral cavity. This is accurately and thoroughly measured using a laser. An implant is designed and manufactured while the operation is in progress using state-of-the-art computer and machining techniques. All important parameters such as neck length, offset, and anteversion are fully variable intraoperatively. To date, more than 800 consecutive procedures have been carried out. In a limited trial, no subjective difference was found with a cemented Charnley total hip arthroplasty at one year. It currently takes about 40 minutes to manufacture the implant and make it available in the operating room, and this time is being continually reduced. Using a femur first approach, operating time is not greatly extended. In the future, perhaps the operating time will not be extended at all. All data including cavity geometry are centrally recorded for analysis.

Adult↗
PubMed1989

Tarsal tunnel syndrome: clinical and pathological results.

The tarsal tunnel syndrome is a complex entity. The condition results from a compression of the posterior tibial nerve, either at its terminal or collateral branches, at the tibio-astragalo-calcaneal canal of Richet. A retrospective study of 27 consecutive cases, treated by epi- or perineural neurolysis, illustrates the variability of the clinical picture but fails to confirm the complete and immediate success of the intervention, as reported by the majority of authors. However, the long-term follow-up shows a significant improvement in the terminal latencies of the posterior tibial nerve at 2 years post-surgery. A pathological study of 20 cadaveric feet discloses microscopic anomalies in 22 of the 120 nerve biopsy specimens.

Adult↗
PubMed1988

Lethal midline granuloma (polymorphic reticulosis) and lymphomatoid granulomatosis. Evidence for a monoclonal T-cell lymphoproliferative disorder.

Lymphomatoid granulomatosis (LG) and polymorphic reticulosis (PR), originally described as distinct entities, now are considered as a single disease process. Common histopathologic features include necrosis, vasculitis, and a granulomatous infiltrate. Such features have led to consider lymphomatoid granulomatosis as a systemic vasculitis; alternatively the possible emergence of an overt lymphoma has suggested that it could be a lymphoproliferative process. To investigate this later hypothesis, the authors analyzed the cellular infiltrate of tissue specimens from two patients with histologic features of LG. The analysis included the study of T-cell antigen expression and DNA rearrangement of the beta T-cell receptor gene. In one patient, the T-cell phenotype of infiltrating cells was abnormal because of antigen loss. In both patients, the cells contained rearranged DNA indicating the presence of a clonal T-cell proliferation. It is concluded that some cases of LG and PR, if not all, are related to a neoplastic T-cell lymphoproliferative disorder.

Adult↗
PubMed1988

The peculiar spectrum of beta-thalassemia genes in Tunisia.

We have determined the spectrum of mutations producing beta-thalassemia (beta-thal) in Tunisia by direct DNA analysis using hybridization with allele-specific oligonucleotide probes and restriction endonuclease assay. In all, 34 unrelated beta-thal patients originating from different parts of the country were available for study. The beta-globin gene cluster of each was subjected to haplotype analysis, and on the basis of this analysis, we tested each patient's DNA for one or more mutations previously shown to be linked to that haplotype. We identified four previously unreported haplotypes and found that this population differs from others in Mediterranean areas in the frequency of the beta-thal haplotypes, the unexpected observation being the high frequency of haplotype IX. Six different point mutations were found, accounting for 62% of beta-thal genes in this Tunisian population. The molecular defects known to be the most frequent in Mediterraneans (nonsense codon 39, IVS1 nt 110, IVS1 nt 6) only make up 37% of the mutant genes. One as yet undescribed mutation (IVS1 nt 2 T----G) was identified by molecular cloning and sequencing. Our results should help the implementation of a prenatal diagnosis program for beta-thal in Tunisia.

Genetic Markers↗
PubMed1988

Alternative transcription and splicing of the human porphobilinogen deaminase gene result either in tissue-specific or in housekeeping expression.

Porphobilinogen deaminase [PBGD; porphobilinogen ammonia-lyase (polymerizing), EC 4.3.1.8] is a cytosolic enzyme involved in the heme biosynthetic pathway. Two isoforms of PBGD, encoded by two mRNAs differing solely in their 5' end, are known: one is found in all cells and the other is present only in erythroid cells. We have previously shown that the human PBGD is encoded by a single gene and have now cloned and characterized this gene, which is split into 15 exons spread over 10 kilobases of DNA. We demonstrate that the two mRNAs arise from two overlapping transcription units. The first one (upstream) is active in all tissues and its promoter has some of the structural features of a housekeeping promoter; the second, located 3 kilobases downstream, is active only in erythroid cells and its promoter displays structural homologies with the beta-globin gene promoters.

Ammonia-Lyases↗
PubMed1988

Identification of a CpG mutation in the coagulation factor-IX gene by analysis of amplified DNA sequences.

In a family with no previous bleeding history, the sister of a single, severely affected haemophilia B patient requested carrier detection and prenatal diagnosis. In Southern blots, using Taq I digested DNA and a factor-IX cDNA probe, a normal invariant band at 1.6 kb was missing in the haemophiliac suggesting the loss of the Taq I site at the 5' end of exon h. A 162 bp sequence which includes the suspected mutant region was amplified by the polymerase chain reaction in each DNA. Two oligonucleotide probes were synthesized and differed by only one base pair which substituted a T for C in the normal Taq I recognition sequence. The amplified DNA was dot-blotted and hybridized with the labelled probes. The altered sequence hybridized to DNA from the affected individual, his sister and her fetus and not to DNA from the normals. The mutation, involving the haemophiliac, his mother, his sister and her fetus, transforms a CGA codon that encodes for arginine in the catalytic domain of the protein into a UGA stop codon.

Adult↗
PubMed1988

Hairy cell leukemia associated with large granular lymphocyte leukemia: immunologic and genomic study, effect of interferon treatment.

The authors describe a patient who presented an association of hairy cell leukemia (HCL) and large granular lymphocyte (LGL) leukemia. An eventual relationship between these two rare entities is analyzed. Hairy cells (HCs) were present in the blood, bone marrow, and spleen. An excess of LGLs was found only in the blood and bone marrow. After splenectomy the patient received an alpha 2-interferon (alpha 2-IFN) treatment. The HCs surface phenotype was mu+delta+kappa+, CD20+, and CD25+. The LGLs consisted in CD3+, CD8+, HNK1+, WT31+ T lymphocytes. These were absent in the spleen. alpha 2-IFN treatment resulted in the disappearance of the HCs in the blood and bone marrow, whereas the LGLs remained unchanged. Before alpha 2-IFN treatment, peripheral blood cells, predominantly LGLs, exerted low cytotoxicity that increased up to a normal level after treatment. Using Southern blotting the authors studied the rearrangements of the T-cell receptor beta--chain (C beta) and gamma-chain (J gamma) genes and immunoglobulin heavy (JH)- and light (C kappa, C lambda)- chain genes. An unique JH and C kappa gene rearrangement was found in the blood and spleen, whereas C beta and J gamma gene rearrangements were present in the blood, not in the spleen. Under alpha 2-IFN treatment, the JH gene rearrangement fainted dramatically, in contrast to that of the C beta gene. The study of messenger RNA (mRNA) of the T cell receptor alpha and beta chains evidenced the 1.3-kilobase (kb) and 1.6-kb bands in the blood and their absence in the spleen. The patient was human T-cell leukemia virus (HTLV)-II negative by Southern analysis of blood and spleen cells. It is concluded that the LGL expansion was clonal and not reactive to the HCL. Although the authors cannot definitely exclude that both HC and LGL proliferations stem in a common leukemic precursor, their findings support an association of the two entities.

Antigens, Surface↗
PubMed1988

Determination of the spectrum of beta-thalassemia genes in Spain by use of dot-blot analysis of amplified beta-globin DNA.

We have delineated the molecular lesions causing beta-thalassemia in Spain, a country that has witnessed the passage of different Mediterranean populations over the centuries, in order to evaluate the extent of heterogeneity of these mutations and to make possible simplified prenatal diagnosis of the disorder in that country. The use of the polymerase chain-reaction (PCR) technique to preferentially amplify beta-globin DNA sequences that contain the most frequent beta-thalassemia mutations in Mediterraneans enabled us to rapidly analyze 58 beta-thalassemia alleles in a dot-blot format either by hybridization with allele-specific radiolabeled oligonucleotide probes or by direct sequence analysis of the amplification product. The Spanish population carries seven different beta-thalassemia mutations; the nonsense codon 39 is predominant (64%), whereas the IVS1 position 110 mutation, the most common cause of beta-thalassemia in the eastern part of the Mediterranean basin, is underrepresented (8.5%). The IVS1 mutation at position 6 accounts for 15% of the defects and leads to a more severe form of beta+-thalassemia than originally described in most of the patients we studied. In this study, we demonstrate further the usefulness of the dot-blot hybridization of PCR-amplified genomic DNA in both rapid population surveys and prenatal diagnosis of beta-thalassemia.

Base Sequence↗
PubMed1988

[Genetic diagnosis of growth disorders].

The capability of examining genetic material with DNA probes and restriction endonucleases has opened up a new approach to clinical problems. Genetic disorders involving growth hormone can now be studied because the growth hormone gene (hGH-N) can be examined directly. Several distinct Mendelian disorders are associated with hGH deficiency. Some are caused by deletion of the hGH-N structural gene. In other instances, linkage analysis confirm that genetic disorders with hGH deficiency may be due to undetectable alterations in the hGH gene, or establish that the genetic abnormality does not involve the GH gene as such but rather affects some other gene essential for the production or release of factors involved in the regulation of growth hormone action.

Growth Disorders↗