| 1. |
- Andersson, Nadine, et al.
(författare)
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Genetic screening of children with suspected inherited bleeding disorders
- 2020
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Ingår i: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 26:2, s. 314-324
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Genetic screening using high-throughput DNA sequencing has become a tool in diagnosing patients with suspected inherited bleeding disorders (IBD). However, its usefulness and diagnostic efficacy in children is unclear.AIM: To evaluate the diagnostic efficacy of genetic screening for IBD in children and downstream further testing.METHODS: After informed consent, children (<18 years) with suspected IBD underwent genetic screening with 94 selected genes.RESULTS: A total of 68 heterozygous class 3-5 variants were detected in 30 children, 2.3 variants per patient. Directed specific functional testing was performed after genetic screening in a subset of patients. Adhering to the ACMG guidelines, the results of functional testing together with family history and previous publications classified three variants as likely disease causing (class 4) and two variants as disease causing (class 5), all in children with thrombocytopenia. The overall diagnostic rate was 16.7% (5/30). Children with thrombocytopenia had a significantly higher rate of significant genetic findings, 5/9 (55.6%) vs. 0/21 (0%; P = .0009).CONCLUSION: We conclude that performing genetic screening in children is an effective tool especially for children with inherited thrombocytopenia and has the possibility to diagnose platelet disorders adequately early in life. Children with bleeding diathesis, normal coagulation work-up and without thrombocytopenia are unlikely to be diagnosed by genetic screening. Ethical issues such as incidental findings, variants associated with cancer and the interpretation of the genetic results into clinical practice remain problematic.
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| 2. |
- Leinøe, Eva, et al.
(författare)
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Application of whole-exome sequencing to direct the specific functional testing and diagnosis of rare inherited bleeding disorders in patients from the Öresund Region, Scandinavia
- 2017
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Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048. ; 179:2, s. 308-322
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Tidskriftsartikel (refereegranskat)abstract
- Rare inherited bleeding disorders (IBD) are a common cause of bleeding tendency. To ensure a correct diagnosis, specialized laboratory analyses are necessary. This study reports the results of an upfront diagnostic strategy using targeted whole exome sequencing. In total, 156 patients with a significant bleeding assessment tool score participated in the study, of which a third had thrombocytopenia. Eighty-seven genes specifically associated with genetic predisposition to bleeding were analysed by whole exome sequencing. Variants were classified according to the five-tier scheme. We identified 353 germline variants. Eight patients (5%) harboured a known pathogenic variant. Of the 345 previously unknown variants, computational analyses predicted 99 to be significant. Further filtration according to the Mendelian inheritance pattern, resulted in 59 variants being predicted to be clinically significant. Moreover, 34% (20/59) were assigned as novel class 4 or 5 variants upon targeted functional testing. A class 4 or 5 variant was identified in 30% of patients with thrombocytopenia (14/47) versus 11% of patients with a normal platelet count (12/109) (P < 0·01). An IBD diagnosis has a major clinical impact. The genetic investigations detailed here extricated our patients from a diagnostic conundrum, thus demonstrating that continuous optimization of the diagnostic work-up of IBD is of great benefit.
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| 3. |
- Szanto, Timea, et al.
(författare)
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Platelet function testing : Current practice among clinical centres in Northern Europe
- 2022
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Ingår i: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 28:4, s. 642-648
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Platelet function tests are used to screen and diagnose patients with possible inherited platelet function defects (IPFD). Some acquired platelet dysfunction may be caused by certain drugs or comorbidities, which need to be excluded before testing. Aims: To identify current practice among centres performing platelet function tests in Northern Europe. Methods: A total of 14 clinical centres from Sweden (six), Finland (two), Denmark (two), Norway (one), Estonia (two) and Iceland (one) completed the survey questionnaire, the population capture area of about 29.5 million. Results: Six of the 14 (42.8%) centres providing platelet function assessment represent comprehensive treatment centres (EUHANET status). A Bleeding score (BS) or ISTH bleeding assessment tool (ISTH BAT score) is evaluated in 11/14 (78.6%) centres and family history in all. Five/14 centres (35.7%) use structured preanalytical patient instructions, and 10/14 (71.4%) recorded questionnaire on the preassessment of avoidance of any drugs or natural products affecting platelet functions. Preliminary investigations of screening tests of coagulation are performed in 10/14 (71.4%), while in 4/14 (28.6%), the diagnostic work-up of IPFD and von Willebrand disease (VWD) is performed simultaneously. The work-up of IPFD includes peripheral blood smear in 10/14 (71.4%), platelet aggregometry in all, flow cytometry in 10/14 (71.4%) and Platelet Function Analysis (PFA) in 3/11 (28.6%). Molecular genetic diagnosis is available in 7/14 (50%) centres. Conclusions: The considerable variability in the current practice illustrates the need for harmonization between the Northern European centres according to the international registers (i.e. EUHASS) and IPFD guidelines (ISTH, EHA).
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| 4. |
- Zaninetti, Carlo, et al.
(författare)
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Validation of immunofluorescence analysis of blood smears in patients with inherited platelet disorders
- 2023
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Ingår i: Journal of Thrombosis and Haemostasis. - : Elsevier BV. - 1538-7933 .- 1538-7836. ; 21:4, s. 1010-1019
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Tidskriftsartikel (refereegranskat)abstract
- Background: Inherited platelet disorders (IPDs) are rare diseases characterized by reduced blood platelet counts and/or impaired platelet function. Recognizing IPDs is advisable but often challenging. The diagnostic tools include clinical evaluation, platelet function tests, and molecular analyses. Demonstration of a pathogenic genetic variant confirms IPDs. We established a method to assess the platelet phenotype on blood smears using immunofluorescence microscopy as a diagnostic tool for IPDs. Objectives: The aim of the present study was to validate immunofluorescence microscopy as a screening tool for IPDs in comparison with genetic screening. Methods: We performed a blinded comparison between the diagnosis made using immunofluorescence microscopy on blood smears and genetic findings in a cohort of 43 families affected with 20 different genetically confirmed IPDs. In total, 76% of the cases had inherited thrombocytopenia. Results: Immunofluorescence correctly predicted the underlying IPD in the vast majority of patients with 1 of 9 IPDs for which the typical morphologic pattern is known. Thirty of the 43 enrolled families (70%) were affected by 1 of these 9 IPDs. For the other 11 forms of IPD, we describe alterations of platelet structure in 9 disorders and normal findings in 2 disorders. Conclusion: Immunofluorescence microscopy on blood smears is an effective screening tool for 9 forms of IPD, which include the most frequent forms of inherited thrombocytopenia. Using this approach, typical changes in the phenotype may also be identified for other rare IPDs.
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