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C M Weemaes

Publications and source records attributed to C M Weemaes.

At least 37 records · Page 2Linked to original sources
PubMed1998

Nibrin, a novel DNA double-strand break repair protein, is mutated in Nijmegen breakage syndrome.

Nijmegen breakage syndrome (NBS) is an autosomal recessive chromosomal instability syndrome characterized by microcephaly, growth retardation, immunodeficiency, and cancer predisposition. Cells from NBS patients are hypersensitive to ionizing radiation with cytogenetic features indistinguishable from ataxia telangiectasia. We describe the positional cloning of a gene encoding a novel protein, nibrin. It contains two modules found in cell cycle checkpoint proteins, a forkhead-associated domain adjacent to a breast cancer carboxy-terminal domain. A truncating 5 bp deletion was identified in the majority of NBS patients, carrying a conserved marker haplotype. Five further truncating mutations were identified in patients with other distinct haplotypes. The domains found in nibrin and the NBS phenotype suggest that this disorder is caused by defective responses to DNA double-strand breaks.

Amino Acid Sequence↗
PubMed1998

A double missense mutation in the ATM gene of a Dutch family with ataxia telangiectasia.

Ataxia telangiectasia (AT) is an autosomal recessive disorder characterized by cerebellar ataxia, telangiectasia, immunodeficiency, elevated alpha-fetoprotein levels, chromosomal instability, predisposition to cancer, and radiation sensitivity. We report the identification of a new, double missense mutation in the ataxia telangiectasia gene (ATM) of a Dutch family. This homozygous mutation consists of two consecutive base substitutions in exon 55: a T-->G transversion at position 7875 of the ATM cDNA and a G-->C transversion at position 7876. These transversions were confirmed by polymerase chain reaction/primer-induced restriction analysis with CelII. The double base substitution results in an amino acid change of an aspartic acid to a glutamic acid at codon 2625 and of an alanine to a proline at codon 2626 of the ATM protein. Both amino acids are conserved between the ATM protein and its functional homolog, the Atm gene product in the mouse. Furthermore, the Chou-Fasman and Robson predictions both demonstrate a change in the secondary structure of the ATM protein carrying the D2625E/A2626P mutation. These findings suggest that the double base substitution in the ATM gene is a disease-causing mutation.

Adolescent↗
PubMed1998

Fine localization of the Nijmegen breakage syndrome gene to 8q21: evidence for a common founder haplotype.

Nijmegen breakage syndrome (NBS) is a rare autosomal recessive disorder characterized by microcephaly, a birdlike face, growth retardation, immunodeficiency, lack of secondary sex characteristics in females, and increased incidence of lymphoid cancers. NBS cells display a phenotype similar to that of cells from ataxia-telangiectasia patients, including chromosomal instability, radiation sensitivity, and aberrant cell-cycle-checkpoint control following exposure to ionizing radiation. A recent study reported genetic linkage of NBS to human chromosome 8q21, with strong linkage disequilibrium detected at marker D8S1811 in eastern European NBS families. We collected a geographically diverse group of NBS families and tested them for linkage, using an expanded panel of markers at 8q21. In this article, we report linkage of NBS to 8q21 in 6/7 of these families, with a maximum LOD score of 3.58. Significant linkage disequilibrium was detected for 8/13 markers tested in the 8q21 region, including D8S1811. In order to further localize the gene for NBS, we generated a radiation-hybrid map of markers at 8q21 and constructed haplotypes based on this map. Examination of disease haplotypes segregating in 11 NBS pedigrees revealed recombination events that place the NBS gene between D8S1757 and D8S270. A common founder haplotype was present on 15/18 disease chromosomes from 9/11 NBS families. Inferred (ancestral) recombination events involving this common haplotype suggest that NBS can be localized further, to an interval flanked by markers D8S273 and D8S88.

Chromosome Breakage↗
PubMed1998

Localization of the ICF syndrome to chromosome 20 by homozygosity mapping.

Immunodeficiency in association with centromere instability of chromosomes 1, 9, and 16 and facial anomalies (ICF syndrome) is a rare autosomal recessive disorder. ICF patients show marked hypomethylation of their DNA; undermethylation of classical satellites II and III is thought to be associated with the centromere instability. We used DNA from three consanguineous families with a total of four ICF patients and performed a total genome screen, to localize the ICF syndrome gene by homozygosity mapping. One chromosomal region (20q11-q13) was consistently found to be homozygous in ICF patients, whereas all healthy sibs showed a heterozygous pattern. Comparison of the regions of homozygosity in the four ICF patients localized the ICF locus to a 9-cM region between the markers D20S477 and D20S850. Analysis of more families will be required, to refine the map location further. Isolation of the gene associated with the ICF syndrome not only will give insight into the etiology of the ICF syndrome but will also broaden our understanding of DNA methylation processes.

Chromosome Mapping↗
PubMed1998

Successful treatment with voriconazole of invasive aspergillosis in chronic granulomatous disease.

A 5-year-old boy with chronic granulomatous disease (CGD) was treated with amphotericin B for an invasive pulmonary Aspergillus nidulans infection. The infection progressed during 6 wk of treatment despite the addition of interferon-gamma (IFN-gamma), filgrastim, and transfusions with donor granulocytes. Treatment with a novel antifungal triazole, voriconazole, resulted in an excellent clinical response.

Amphotericin B↗
PubMed1997

[Chronic fatigue syndrome in young persons].

The prevalence of chronic fatigue syndrome (CFS) in teenagers is 10-20 per 100,000 inhabitants in the Netherlands. The natural course of the disorder is not favourable according to the literature. Proposed criteria for the diagnosis 'CFS' in adolescence are: absence of a physical explanation for the complaints, a disabling fatigue for at least six months and prolonged school absenteeism or severe motor and social disabilities. Exclusion criterion should be a psychiatric disorder. Factors that attribute to the persistence of fatigue are somatic attributions, illness enhancing cognitions and behaviour of parents as well as physical inactivity. The role of the physician and the role of parents can enhance the problems. The treatment should focus on decreasing the somatic attributions, on reinforcement by the parents of healthy adolescent behaviour, on the gradual increase of physical activity and on decreasing attention (including medical attention) for the somatic complaints.

Adolescent↗
PubMed1997

T cell subsets and T cell function in cartilage-hair hypoplasia.

Cartilage hair hypoplasia is a rare autosomal recessive form of short-limbed dwarfism associated with a cellular immunodeficiency. In eight patients, the authors studied the presence of T cell subsets and in vitro T cell function in order to address the basis for the immunological disorder. Both the proliferative response to phytohaemagglutinin (PHA) and the PHA-induced IL2 production were 60% lower compared with controls (P = 0.007 and 0.005, respectively). The impaired proliferative response could not be restored by addition of IL-2. This result is in accordance with a decrease in the percentage of activated T cells expressing the p55 subunit of the IL-2 receptor complex (CD25). The results define more precisely that T cells from cartilage hair hypoplasia patients are defective in the transition from the G0 to the G1 phase of the cell cycle. Furthermore, the data demonstrate that several CHH patients show a reduced proportion of CD45RA+ 'naive' T cells. However, the in vitro impairment of T cell function cannot solely be explained by imbalance between 'naive' and 'memory' T cells. Although CHH patients with a history of recurrent respiratory tract infections showed the most aberrant in vitro immune parameters, a clear relationship between clinical data and in vitro parameters could not be established for the whole patient group.

Adult↗
PubMed1996

CD4 deficiency in myelodysplastic syndrome with monosomy 7.

UNLABELLED: We describe a patient with myelodysplastic syndrome with monosomy 7 presenting with a T-cell defect. He suffered from infections from the age of 10 years, when a CD4 deficiency and impaired lymphoproliferative responses in vitro were found. The only symptom of a myelodysplastic syndrome at that time was thrombocytopenia with giant platelets. Monosomy 7 was found in the bone marrow cells. At the age of 11 years he developed other characteristics of monosomy 7 including splenomegaly and anaemia. Some months later leukaemia was diagnosed. CONCLUSION: In non-HIV CD4 deficiency myelodysplastic syndrome has to be considered.

CD4 Antigens↗
PubMed1996

Can human polyclonal immunoglobulin raise the threshold for convulsions in rats?

In the present preliminary study we explored the possibility of an anticonvulsant effect of normal human immunoglobulin in an animal epilepsy model based on direct cortical stimulation in freely moving rats. After human immunoglobulin administration a significant and prolonged elevation of the threshold for convulsions was measured in 12% (6/49) of the total group of outbred Wistar rats. In the subgroup of more than seven months old Wistar rats this was 67% (6/9). When a threshold increasing effect of immunoglobulin occurred, it was detectable within 0.5-1 hour after administration, reached its maximum after approximately two hours and continued for at least 40 hours.

Animals↗
PubMed1995

Altered immunoglobulin concentrations and light chain ratios in juvenile onset mixed connective tissue disease.

Immunological disturbances may result in altered immunoglobulin concentrations and kappa/lambda light chain (kappa/lambda) ratios. We measured the kappa/lambda ratios of total serum immunoglobulins and of polyclonal IgG, A, and M separately as well as concentrations of these immunoglobulins in fourteen patients with juvenile onset mixed connective tissue disease. When comparing the patient group with a reference group the mean serum IgG and IgA concentrations were respectively 2.98 G/L (p = 0.0012) and 0.79 G/L (p = 0.0114) higher in the group of patients with juvenile onset mixed connective tissue disease. The mean IgM concentration was 0.39 G/L (p = 0.0002) lower. The mean kappa/lambda ratios of total serum immunoglobulins, serum IgG, and serum IgA were respectively 0.20 (p = 0.0226), 0.28 (p = 0.0016) and 0.10 (p = 0.0732), higher in the group of patients with mixed connective tissue disease as compared with the reference group. Mean serum IgM kappa/lambda ratio, however, was 0.21 (p = 0.0046) lower. The alterations of the serum immunoglobulin concentrations and of the kappa/lambda ratios reflect immunological disturbances in patients with juvenile onset mixed connective tissue disease. The increased concentration of serum IgG and raised IgG kappa/lambda ratio and decreased concentration of serum IgM with decreased IgM kappa/lambda ratio indicate that the synthesis of kappa-bearing immunoglobulins mainly is affected.

Adolescent↗
PubMed1995

A dysbalanced immune system in cryptogenic Lennox-Gastaut syndrome.

In children with cryptogenic Lennox-Gastaut syndrome we found a functionally impaired humoral immune response to a primary antigen (haemocyanin), despite signs of a triggered immune system consisting of elevated IgG concentrations. This combination of immunological findings, considered to be the expression of a dysbalanced-triggered as well as functionally impaired-immune system, has also been described in an auto-immune disease like systemic lupus erythaematodes in humans, and in genetically epilepsy-prone rats. The interactions between the immune system and the nervous system in Lennox-Gastaut syndrome will be discussed.

Adolescent↗
PubMed1994

[Immunodeficiency in The Netherlands: clinical and immunological survey, 1970-1983. Interfacultaire werkgroep Immunodeficiëntie].

OBJECTIVE: Inventory of patients with immunodeficiency in the Netherlands. DESIGN: Retrospective over the period 1970-1983. SETTING: Dutch Working Group on Immunodeficiency, University Children's Hospital, 'Het Wilhelmina Kinderziekenhuis', Utrecht. METHOD: A questionnaire with specific information on immunodeficient patients was completed by clinical members of the Working Group i.e. paediatricians and internists. Diagnosis of the immunodeficiency was according to WHO recommendations. RESULTS: The data of 336 patients could be included and analysed. Defects in humoral immunity were the most common (62.9%), followed by combined defects (18.75%), T cell defects (7.4%), phagocytic disorders (6.8%) and complement component deficiencies (2.7%). Sixty-two patients (15.5%) died, notably those with combined T and B cell defects, selective T cell defects and those with immunodeficiency based on DNA repair defects. Autoimmunity was relatively frequent in immunodeficiency (7.7%) as was cancer (2.7%). CONCLUSION: Results were similar to those of other European countries.

Antibody Formation↗
PubMed1994

Late-onset ataxia telangiectasia in two brothers presenting with juvenile resting tremor.

Two young adult brothers presented with a 5- to 6-Hz resting tremor of the upper limbs. Although ataxia was not unequivocally present and ocular telangiectasia was minimal, typical rearrangements of chromosomes 7 and 14, and increased alpha-feto-protein levels indicated the presence of ataxia telangiectasia (AT). Resting tremor as a predominating symptom in AT is uncommon and to our knowledge has not been described previously.

Adult↗
PubMed1994

ICF syndrome: a new case and review of the literature.

Patients with ICF syndrome can be recognized by the presence of a variable immunodeficiency, instability of the pericentromeric heterochromatin of, in particular, chromosomes 1, 9, and 16 in cultured peripheral lymphocytes, and a number of facial anomalies. Recently, aberrations at the molecular level have been described, consisting of alterations in the methylation pattern of classical satellite DNA, in a number of patients. ICF syndrome is considered to be inherited in an autosomal recessive manner and may be rare, as only 14 patients have been described thus far. We present a new case, a boy with agammaglobulinemia, who was extensively studied by means of classical cytogenetics and fluorescent in situ hybridization. All patients previously reported in the literature are reviewed.

Agammaglobulinemia↗
PubMed1994

High-dose intravenous immunoglobulin treatment in cryptogenic West and Lennox-Gastaut syndrome; an add-on study.

In an add-on pilot study, a group of 15 children with cryptogenic and intractable West syndrome (3) and Lennox-Gastaut syndrome (12) received intravenous immunoglobulin (IVIg, 0.4 g/kg body weight per day for 5 consecutive days, followed by the same dose once every 2 weeks for 3 months). Five patients had been treated previously with ACTH without success. The reduction in clinical seizures averaged 70%. Electroencephalographic (EEG) recordings revealed a mean reduction in epileptic discharges of 40%. In all 15 patients, acceleration of EEG background activity occurred, and psychomotor development improved. Prior to IVIg administration, CSF examinations were normal. After IVIg administration, the serum total IgG concentration increased by an average of 76%, and the CSF IgG concentration by 44%. According to our data, IVIg crosses the blood-CSF barrier, and might be effective in the treatment of West syndrome and Lennox-Gastaut syndrome. We suggest it should be considered when other treatments, such as ACTH, have failed.

Child↗
PubMed1994

Cerebrospinal fluid examinations in cryptogenic West and Lennox-Gastaut syndrome before and after intravenous immunoglobulin administration.

Before and after administration of intravenous immunoglobulin (IVIg), cerebrospinal fluid (CSF) was examined in a homogeneous group of 15 patients with cryptogenic types of West syndrome (WS) and Lennox-Gastaut syndrome (LGS). The purpose of the present CSF study was: (i) to elucidate possible etiological factors and consequences of these severe forms of epilepsy, and (ii) to elucidate mechanisms of action and adverse effects of IVIg. Hypotheses concerning etiological factors like central nervous system infections, neuroimmunological disorders, or disturbances in neurotransmitter metabolites could not be confirmed. These normal CSF findings are in accordance with the concept of a cryptogenic etiology of the epilepsies in the reported patients. Nor could we confirm hypotheses concerning seizure consequences, such as increased blood-CSF permeability, increased markers of brain cell destruction, or increased metabolic components. Following IVIg administration in these patients, all with an on the whole undisturbed blood-CSF barrier permeability as measured by Q albumin, the CSF IgG concentrations increased significantly and proportionally to the Q albumin level. No signs of adverse effects of IVIg such as aseptic meningoencephalitis were found in 165 infusions of IVIg performed in the 15 children.

Child↗
PubMed1994

Immunoglobulin treatment in epilepsy, a review of the literature.

The purpose of this study is to ascertain possible efficacy and to understand possible mechanisms of action of intramuscular or intravenous immunoglobulin (IVIg) in the treatment of intractable epilepsy, through a review of all identifiable articles on this topic. In 24 studies, none with a placebo controlled design, 368 patients with epilepsy receiving IVIg were identified. Patients' ages ranged from < 1 to 35 years, mean 7.3 years. Female/male ratio was 0.6. All patients were reported to suffer from intractable epilepsy. The average percentage of patients with an IgG2 deficiency was 25%. The total dose of IVIg varied between 0.3 and 6.8 g/kg for a period of 0.15 to 12 months. Whenever reported, adverse effects of IVIg were minimal. None of the studies reported the need of cessation of IVIg administration due to adverse effects. On the average, the mean clinical seizure reduction and the mean EEG improvement were 52% and 45%, respectively. On the average the percentage of patients with complete seizure remission and the percentage of patients with behavioral improvement were 23% and 63%, respectively. Cumulative meta-analysis of the identified articles is not possible due to the lack of controlled studies, the heterogeneity of the available studies, and the possible publication bias of unpublished negative data. Given these pitfalls, this literature study nevertheless allows some conclusions: (i) There is no formal proof of efficacy of IVIg treatment in epilepsy, and the present review underscores the need of controlled clinical trials before firm conclusions concerning efficacy can be drawn. The uncontrolled clinical observations discussed in this 'state-of-the-art' review generate suggestive evidence at best. They suggest that IVIg might be effective in some patients with intractable epilepsy, and may be considered as a safe add-on medication in various types of idiopathic and symptomatic intractable epilepsy. (ii) Review of the literature did not help in explaining intractable epilepsy or the mechanism of action of IVIg, but did permit some inferences that could serve to design future clinical and experimental approaches to IVIg administration in epilepsy.

Adolescent↗