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Contains fulltext : 307450.pdf (Publisher’s version ) (Open Access)

Contains fulltext : 299979.pdf (Publisher’s version ) (Closed access), 01 november 2023

Item does not contain fulltext, BACKGROUND: Treatment of animal models with ataxia telangiectasia (A-T) with nicotinamide riboside (NR) improved their neurological outcome and survival. OBJECTIVE: The aim of this study is to investigate the effects of NR in patients with A-T. METHODS: In this open-label, proof-of-concept study, 24 patients with A-T were treated with NR during four consecutive months. The effects of NR on ataxia, dysarthria, quality of life, and laboratory parameters were analyzed. RESULTS: During treatment, ataxia scores improved; mean total Scale for the Assessment and Rating of Ataxia and International Cooperative Ataxia Rating Scale scores decreased to 2.4 and 10.1 points, respectively. After NR withdrawal, ataxia scores worsened. In immunodeficient patients, the mean serum IgG concentration increased substantially until the end of the study period with 0.52 g/L. Untargeted metabolomics analysis revealed increased plasma levels of NR metabolites and purine nucleosides during treatment. Adverse effects did not occur. CONCLUSIONS: Treatment with NR is tolerated well and associated with improvement in ataxia and serum immunoglobulin concentrations in patients with A-T. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Contains fulltext : 235465.pdf (Publisher’s version ) (Open Access)

Contains fulltext : 232754.pdf (Publisher’s version ) (Open Access), AIM: To investigate the characteristics and severity of dysarthria in children and adults with ataxia telangiectasia. METHOD: All children and adults with ataxia telangiectasia who visited our multidisciplinary outpatient clinic for ataxia telangiectasia were asked to participate in this study, which took place in March 2019. To evaluate dysarthria, we used the Radboud Dysarthria Assessment in adults (older than 18y) and the paediatric Radboud Dysarthria Assessment in children (5-18y), including the observational tasks 'conversation' and 'reading', and the speech-related maximum performance tasks 'repetition rate', 'phonation time', 'fundamental frequency range', and 'phonation volume'. Speech intelligibility was measured using the Intelligibility in Context Scale. RESULTS: Twenty-two individuals (15 children [5-17y], seven adults [19-47y]; 14 males and eight females; mean age 19y, SD 15y 2mo) participated. Dysarthria was present in all participants and characterized by ataxic components in adults and similar uncontrolled movements in children. In most participants, speech was mildly to mildly/severely affected. Almost all participants had an abnormal score for at least one maximum performance task. INTERPRETATION: Dysarthria in ataxia telangiectasia is characterized by uncontrolled, ataxic, and involuntary movements, resulting in monotonous, unstable, slow, hypernasal, and chanted speech. WHAT THIS PAPER ADDS: Dysarthria in ataxia telangiectasia is characterized by uncontrolled, ataxic, and involuntary movements. Dysarthria in ataxia telangiectasia results in monotonous, unstable, slow, hypernasal, and chanted speech. Dysarthria in ataxia telangiectasia can be assessed using the Radboud Dysarthria Assessment and the paediatric Radboud Dysarthria Assessment.

Radboud University, 19 maart 2021, Promotores : Willemsen, M.A.A.P., Warrenburg, B.P.C. van de Co-promotores : Weemaes, C.M.R., Roeleveld, N., Contains fulltext : 230651.pdf (publisher's version ) (Open Access)

Radboud University, 05 maart 2021, Promotor : Willemsen, M.A.A.P. Co-promotores : Weemaes, C.M.R., Burg, M. van der, Contains fulltext : 230643.pdf (Publisher’s version ) (Open Access)

Contains fulltext : 218804.pdf (publisher's version ) (Open Access), OBJECTIVE: Patients with classic ataxia-telangiectasia (A-T) generally die in the second or third decade of life. Clinical descriptions of A-T tend to focus on the symptoms at presentation. However, during the course of the disease, other symptoms and complications emerge. As long-term survivors with classic A-T develop a complex multisystem disorder with a largely unknown extent and severity, we aimed to comprehensively assess their full clinical picture. METHODS: Data from Dutch patients with classic A-T above the age of 30 years were retrospectively collected. In addition, we searched the literature for descriptions of classic A-T patients who survived beyond the age of 30 years. RESULTS: In the Dutch cohort, seven classic A-T patients survived beyond 30 years of age. Fourteen additional patients were retrieved by the literature search. Common problems in older patients with classic A-T were linked to ageing. Most patients had pulmonary, endocrine, cardiovascular, and gastro-intestinal problems. All patients had a tetraparesis with contractures. This led to immobilization and frequent hospital admissions. Most patients expressed the wish to no longer undergo intensive medical treatments, and waived follow-up programs. CONCLUSIONS: Paucity of descriptions in the literature, and withdrawal from medical care complicate the acquisition of follow-up data on the natural history of long-term survivors. Irrespective of these limitations, we have obtained impression of the many problems that these patients face when surviving beyond 30 years of age. Awareness of these problems is needed to guide follow-up, counselling, and (palliative) care; decisions about life-prolonging treatments should be well considered.

01 februari 2020, Contains fulltext : 218859.pdf (Publisher’s version ) (Open Access), Ataxia telangiectasia (A-T) is a severe neurodegenerative disorder with variable immunodeficiency. Together with the Dutch A-T community, we investigated the opinion of A-T parents on an early A-T diagnosis in the asymptomatic phase of the disease. During an annual national meeting for A-T patients and families, the topic of an early A-T diagnosis was discussed in relation to the recent introduction of neonatal screening for severe combined immunodeficiency (SCID) in the Netherlands. Based on the discussion, individual arguments were identified and processed into a questionnaire, which was sent out to 64 A-T parents (32 families). Arguments included were insecurity to diagnosis, possible medical advantages, appropriate genetic counseling and family planning, loss of "golden" year(s), and early cancer screening for parents. The response rate was 55% (n = 35 parents). Twenty-six (74%) parents felt that the advantages of an early diagnosis outweighed the disadvantages, five parents thought that the disadvantages would outweigh the advantages (14%), and four parents did not indicate a preference.Conclusion: The majority of parents of a child with A-T would have preferred an early diagnosis during the asymptomatic phase of the disease, because the uncertainty during the diagnostic process had had a major impact on their lives. In addition, the knowledge of being carriers of an ATM gene mutation influenced decisions about family planning. Parents who opposed against an early diagnosis emphasized the joy of having a seemingly healthy child until diagnosis.What is Known:* Ataxia telangiectasia (A-T) is a devastating DNA repair disorder with a huge impact on quality of life of patients and their parents.* Patients with A-T may incidentally be identified at birth as the consequence of neonatal screening for severe combined immunodeficiency (SCID).What is New:* The majority of Dutch parents of A-T patients (74%) would have preferred an early diagnosis of their child in the asy

Contains fulltext : 203873.pdf (publisher's version ) (Closed access)

Item does not contain fulltext, Patient registries are instrumental for clinical research in rare diseases. They help to achieve a sufficient sample size for epidemiological and clinical research and to assess the feasibility of clinical trials. The European Society for Immunodeficiencies (ESID) registry currently comprises information on more than 25,000 patients with inborn errors of immunity (IEI). The prerequisite of a patient to be included into the ESID registry is an IEI either defined by a defect in a gene included in the disease classification of the international union of immunological societies, or verified by applying clinical criteria. Because a relevant number of patients, including those with common variable immunodeficiency (CVID), representing the largest group of patients in the registry, remain without a genetic diagnosis, consensus on classification of these patients is mandatory. Here, we present clinical criteria for a large number of IEI that were designed in expert panels with an external review. They were implemented for novel entries and verification of existing data sets from 2014, yielding a substantial refinement. For instance, 8% of adults and 27% of children with CVID (176 of 1704 patients) were reclassified to 22 different immunodeficiencies, illustrating progress in genetics, but also the previous lack of standardized disease definitions. Importantly, apart from registry purposes, the clinical criteria are also helpful to support treatment decisions in the absence of a genetic diagnosis or in patients with variants of unknown significance.

Item does not contain fulltext

Contains fulltext : 213591.pdf (publisher's version ) (Open Access)

Contains fulltext : 202704.pdf (publisher's version ) (Closed access), OBJECTIVE: To describe and classify the neurologic trajectories in patients with mild neurologic forms of ataxia telangiectasia (A-T) from the Dutch A-T cohort, combined with patients reported in the literature. METHODS: Clinical, genetic, and laboratory data of 14 patients with mild neurologic phenotypes of A-T from the Dutch cohort were analyzed and combined with corresponding data from the literature. A mild neurologic phenotype was defined by a later onset, nonataxia presenting or dominant feature, or slower progression compared to the classic A-T phenotype. Neurologic trajectories were classified based on age at onset, presenting feature, and follow-up data. RESULTS: One hundred five patients were included in the study. Neurologic trajectories were categorized into 6 groups: patients with childhood-onset extrapyramidal (EP) features with cerebellar symptoms developing later (group 1; 18 patients), childhood-onset cerebellar symptoms, with EP features developing later (group 2; 35 patients), childhood- to adolescence-onset dystonia, without cerebellar symptoms (group 3; 23 patients), childhood- to adolescence-onset isolated cerebellar symptoms (group 4; 22 patients), childhood- to adult-onset prominent muscle weakness (group 5; 2 patients), and patients with adult-onset EP features, with anterior horn cell disease arising subsequently (group 6; 5 patients). CONCLUSIONS: This systematic study of the different motor abnormalities and their course over time in patients with mild phenotypes of A-T, enabled us to recognize 6 essentially different phenotypic patterns. Awareness of these different trajectories of motor abnormalities in milder forms of A-T will contribute to a reduction of diagnostic delay in this severe multisystem disorder.

Contains fulltext : 183882.pdf (publisher's version ) (Open Access)

Contains fulltext : 190016.pdf (Publisher’s version ) (Open Access)

Contains fulltext : 177204.pdf (publisher's version ) (Closed access)

Contains fulltext : 174098.pdf (publisher's version ) (Open Access), Ataxia-telangiectasia (AT) is a neurodegenerative disorder characterized by ataxia, telangiectasia, and immunodeficiency. An increased risk of malignancies and respiratory diseases dramatically reduce life expectancy. To better counsel families, develop individual follow-up programs, and select patients for therapeutic trials, more knowledge is needed on factors influencing survival. This retrospective cohort study of 61 AT patients shows that classical AT patients had a shorter survival than variant patients (HR 5.9, 95%CI 2.0-17.7), especially once a malignancy was diagnosed (HR 2.5, 95%CI 1.1-5.5, compared to classical AT patients without malignancy). Patients with the hyper IgM phenotype with hypogammaglobulinemia (AT-HIGM) and patients with an IgG2 deficiency showed decreased survival compared to patients with normal IgG (HR 9.2, 95%CI 3.2-26.5) and patients with normal IgG2 levels (HR 7.8, 95%CI 1.7-36.2), respectively. If high risk treatment trials will become available for AT, those patients with factors indicating the poorest prognosis might be considered for inclusion first.

Bloom’s syndrome (BS) is an autosomal recessive disease, caused by mutations in the BLM gene. This gene codes for BLM protein, which is a helicase involved in DNA repair. DNA repair is especially important for the development and maturation of the T and B cells. Since BLM is involved in DNA repair, we aimed to study if BLM deficiency affects T and B cell development and especially somatic hypermutation (SHM) and class switch recombination (CSR) processes. Clinical data of six BS patients was collected, and immunoglobulin serum levels were measured at different time points. In addition, we performed immune phenotyping of the B and T cells and analyzed the SHM and CSR in detail by analyzing IGHA and IGHG transcripts using next-generation sequencing. The serum immunoglobulin levels were relatively low, and patients had an increased number of infections. The absolute number of T, B, and NK cells were low but still in the normal range. Remarkably, all BS patients studied had a high percentage (20–80%) of CD4+ and CD8+ effector memory T cells. The process of SHM seems normal; however, the Ig subclass distribution was not normal, since the BS patients had more IGHG1 and IGHG3 transcripts. In conclusion, BS patients have low number of lymphocytes, but the immunodeficiency seems relatively mild since they have no severe or opportunistic infections. Most changes in the B cell development were seen in the CSR process; however, further studies are necessary to elucidate the exact role of BLM in CSR.

Item does not contain fulltext, Retrotransposon-mediated insertion of a long interspersed nuclear element (LINE)-1 or an Alu element into a human gene is a well-known pathogenic mechanism. We report a novel LINE-1-mediated insertion of a transcript from the TMF1 gene on chromosome 3 into the CYBB gene on the X-chromosome. In a Dutch male patient with chronic granulomatous disease, a 5.8-kb, incomplete and partly exonized TMF1 transcript was identified in intron 1 of CYBB, in opposite orientation to the host gene. The sequence of the insertion showed the hallmarks of a retrotransposition event, with an antisense poly(A) tail, target site duplication, and a consensus LINE-1 endonuclease cleavage site. This insertion induced aberrant CYBB mRNA splicing, with inclusion of an extra 117-bp exon between exons 1 and 2 of CYBB. This extra exon contained a premature stop codon. The retrotransposition took place in an early stage of fetal development in the mother of the patient, because she showed a somatic mosaicism for the mutation that was not present in the DNA of her parents. However, the mutated allele was not expressed in the patient's mother because the insertion was found only in the methylated fraction of her DNA.

Contains fulltext : 137474.pdf (publisher's version ) (Closed access), Alpha-fetoprotein (AFP) is present in fetal serum in concentrations up to 5,000,000 mug/l. After birth, AFP gene expression is turned down with a subsequent fall of the serum concentrations of this albumin-like protein to 'adult values' of circa 0.5-15 mug/l from the age of 2 years onwards. Irrespective of its assumed important functions, individuals with AFP deficiency appear fully healthy. The other way around, the presence of AFP in the circulation after the first years of life doesn't seem to harm, since individuals with 'hereditary persistence of AFP' are also without clinical abnormalities. During pregnancy, AFP (in maternal serum) has long been recognized as a marker for congenital anomalies of the fetus. Equally well known is AFP as biomarker for hepatocellular carcinoma and some other malignancies. There are at least four neurodegenerative disorders, all inherited as autosomal recessive traits and characterized by the presence of cerebellar ataxia, abnormal ocular movements, and neuropathy, for which an elevated concentration of serum AFP is an important diagnostic biomarker. The availability of a reliable biomarker is not only important during screening or diagnostic processes, but is also relevant for objective follow-up during (future) therapeutic interventions.

Contains fulltext : 117756.pdf (publisher's version ) (Closed access), BACKGROUND: Ataxia telangiectasia (AT) is a multisystem DNA-repair disorder caused by mutations in the ataxia telangiectasia mutated (ATM) gene. Patients with AT have reduced B- and T-cell numbers and a highly variable immunodeficiency. ATM is important for V(D)J recombination and immunoglobulin class-switch recombination (CSR); however, little is known about the mechanisms resulting in antibody deficiency severity. OBJECTIVE: We sought to examine the immunologic mechanisms responsible for antibody deficiency heterogeneity in patients with AT. METHODS: In this study we included patients with classical AT plus early-onset hypogammaglobulinemia (n = 3), classical AT (n = 8), and variant AT (late onset, n = 4). We studied peripheral B- and T-cell subsets, B-cell subset replication history, somatic hypermutation frequencies, CSR patterns, B-cell repertoire, and ATM kinase activity. RESULTS: Patients with classical AT lacked ATM kinase activity, whereas patients with variant AT showed residual function. Most patients had disturbed naive B-cell and T-cell homeostasis, as evidenced by low cell numbers, increased proliferation, a large proportion CD21(low)CD38(low) anergic B cells, and decreased antigen receptor repertoire diversity. Impaired formation of T cell-dependent memory B cells was predominantly found in patients with AT plus hypogammaglobulinemia. These patients had extremely low naive CD4(+) T-cell counts, which were more severely reduced compared with those seen in patients with classical AT without hypogammaglobulinemia. Finally, AT deficiency resulted in defective CSR to distal constant regions that might reflect an impaired ability of B cells to undergo multiple germinal center reactions. CONCLUSION: The severity of the antibody deficiency in patients with AT correlates with disturbances in B- and T-cell homeostasis resulting in reduced immune repertoire diversity, which consequently affects the chance of successful antigen-dependent cognate B-T interaction.

1 november 2013, Item does not contain fulltext, Immunodeficiency with centromeric instability and facial anomalies (ICF) syndrome is a primary immunodeficiency, predominantly characterized by agammaglobulinemia or hypoimmunoglobulinemia, centromere instability and facial anomalies. Mutations in two genes have been discovered to cause ICF syndrome: DNMT3B and ZBTB24. To characterize the clinical features of this syndrome, as well as genotype-phenotype correlations, we compared clinical and genetic data of 44 ICF patients. Of them, 23 had mutations in DNMT3B (ICF1), 13 patients had mutations in ZBTB24 (ICF2), whereas for 8 patients, the gene defect has not yet been identified (ICFX). While at first sight these patients share the same immunological, morphological and epigenetic hallmarks of the disease, systematic evaluation of all reported informative cases shows that: (1) the humoral immunodeficiency is generally more pronounced in ICF1 patients, (2) B- and T-cell compartments are both involved in ICF1 and ICF2, (3) ICF2 patients have a significantly higher incidence of intellectual disability and (4) congenital malformations can be observed in some ICF1 and ICF2 cases. It is expected that these observations on prevalence and clinical presentation will facilitate mutation-screening strategies and help in diagnostic counseling.

Radboud Universiteit Nijmegen, 8 oktober 2012, Promotores : Willemsen, M.A.A.P., Kremer, H.P.H. Co-promotores : Deuren, M. van, Weemaes, C.M.R., Contains fulltext : 99156.pdf (publisher's version ) (Open Access)