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Bowyer A.E.,Sheffield Haemophilia and Thrombosis Center | Goodeve A.,Sheffield Diagnostic Genetics Service | Goodeve A.,University of Sheffield | Liesner R.,Haemostasis and Thrombosis Center | And 4 more authors.
British Journal of Haematology | Year: 2011

Haemophilia A is caused by a reduction in clotting factor VIII (FVIII). FVIII coagulant activity (FVIII:C) can be measured by three methods; the one-stage activated partial thromboplastin time-based clotting assay, the two-stage Xa generation-based clotting assay and the chromogenic Xa generation-based assay. The FVIII:C of most patients with haemophilia A are concordant regardless of the assay method employed. Up to a third of patients show assay discrepancy, usually with the two-stage and chromogenic assays being much lower than the one-stage assay. Very rarely, patients have been reported with lower one-stage compared to two-stage and chromogenic assays, but here we report that the mutation p.Tyr365Cys accounts for most of these patients and, at least in the UK, is not rare. We have identified this mutation in 23 different families. Affected male index individuals had a lower mean one-stage FVIII:C of 27iu/dl compared to two-stage FVIII:C mean of 77iu/dl. Affected individuals had minimal or absent bleeding symptoms and when these were present they were usually in patients with another co-inherited bleeding disorder. Affected individuals often had surgery without the need to correct the one-stage FVIII:C. © 2011 Blackwell Publishing Ltd.


Sequeiros J.,University of Porto | Seneca S.,Center for Medical Genetics | Martindale J.,Sheffield Diagnostic Genetics Service
European Journal of Human Genetics | Year: 2010

Many laboratories worldwide are offering molecular genetic testing for spinocerebellar ataxias (SCAs). This is essential for differential diagnosis and adequate genetic counselling. The European Molecular Genetics Quality Network (EMQN) started an SCA external quality assessment scheme in 2004. There was a clear need for updated laboratory guidelines. EMQN and EuroGentest organized a Best Practice (BP) meeting to discuss current practices and achieve consensus. A pre-meeting survey showed that 36 laboratories (20 countries) conducted nearly 18 000 SCA tests the year before, and identified issues to discuss. Draft guidelines were produced immediately after the meeting and discussed online for several months. The final version was endorsed by EMQN, and harmonized with guidelines from other oligonucleotide repeat disorders. We present the procedures taken to organize the survey, BP meeting, as well as drafting and approval of BP guidelines. We emphasize the most important recommendations on (1) pre-test requirements, (2) appropriate methodologies and (3) interpretation and reporting, and focus on the discussion of controversial issues not included in the final document. In addition, after an extensive review of scientific literature, and responding to recommendations made, we now produce information that we hope will facilitate the activities of diagnostic laboratories and foster quality SCA testing. For the main loci, this includes (1) a list of repeat sequences, as originally published; (2) primers in use; and (3) an evidence-based description of the normal and pathogenic repeat-size ranges, including those of reduced penetrance and those in which there is still some uncertainty. This information will be maintained and updated in http://www.scabase.eu. © 2010 Macmillan Publishers Limited All rights reserved.


Keeney S.,Royal Infirmary | Collins P.,University of Cardiff | Cumming A.,Royal Infirmary | Goodeve A.,Sheffield Diagnostic Genetics Service | Pasi J.,Haemophilia Center
Seminars in Thrombosis and Hemostasis | Year: 2011

The UK treatment strategy for von Willebrand disease (VWD) is based on consensus guidelines produced by the United Kingdom Haemophilia Centre Doctors' Organization (UKHCDO) relating to the diagnosis and management of VWD. Selection of therapeutic products suitable for treatment of this complex inherited bleeding disorder is based on the observed response. Desmopressin (DDAVP), an analog of vasopressin, is the recommended treatment in individuals who respond to this drug on trial infusion. DDAVP clearly has no effect in type 3 VWD but may have variable clinical effect in individuals with other subtypes or may be contraindicated in some cases. In patients where DDAVP treatment is unsuitable, replacement factor concentrate containing von Willebrand factor (VWF) is the recommended alternative. Relevant concentrates are available for all patients in the United Kingdom, and treatment is administered by a network of 67 hemophilia treatment centers that also provide specialist care for individuals diagnosed with VWD. Patients diagnosed with the condition are registered on a national inherited bleeding disorder database administered by the UKHCDO on behalf of the Department of Health to aid in service planning and commissioning. Genetic testing is employed in the United Kingdom in certain situations, which is also performed in accordance with current UKHCDO guidelines. © 2011 by Thieme Medical Publishers, Inc.


Perry D.J.,University of Cambridge | Cumming T.,University of Manchester | Goodeve A.,Sheffield Diagnostic Genetics Service | Hill M.,University of Nottingham | And 3 more authors.
Seminars in Thrombosis and Hemostasis | Year: 2014

Molecular genetic analysis of families with hemophilia and other heritable bleeding disorders is a frequently requested laboratory investigation. In the United Kingdom, laboratories undertaking genetic testing must participate in a recognized external quality assessment scheme for formal accreditation. The UK National External Quality Assessment Scheme (UK NEQAS) for heritable bleeding disorders was established in its current format in 2003, and currently has 27 registered participants in the United Kingdom, the European Union (EU), and the non-EU countries. Two exercises per annum are circulated to participants comprising either whole blood or DNA isolated from cell lines, and laboratories are allowed 6 weeks to analyze the samples and generate a report. Reports are assessed by a panel comprising clinicians and scientists with expertise in this area. Samples to date have involved analysis of the F8 gene (10 exercises), the F9 gene (4 exercises), and the VWF gene (3 exercises) and have comprised a wide spectrum of mutations representing the routine workload encountered in the molecular genetics laboratory. The majority of laboratories in each exercise passed, but a small number did not and reasons for failing included clerical errors, genotyping inaccuracies, and a failure to correctly interpret data. Overall we have seen an improvement in quality of reports submitted for assessment, with a more concise format that will be of value to referring clinicians and counsellors. Informal feedback from participants has been very positive. © 2014 by Thieme Medical Publishers, Inc.


Balasubramanian M.,Sheffield Clinical Genetics Service | Smith K.,Sheffield Diagnostic Genetics Service | Mordekar S.R.,Sheffield Childrens NHS Foundation Trust | Parker M.J.,Sheffield Clinical Genetics Service
European Journal of Medical Genetics | Year: 2011

Chromosome 16p13.11 has recently been reported as a region of recurrent microdeletion/duplication, which may contribute to a specific clinical phenotype of epilepsy, significant learning difficulties and distinct facial dysmorphism. The 16p13.11 microdeletion syndrome is associated with schizophrenia, developmental delay and idiopathic generalised epilepsy. Haploinsufficiency of genes in 16p13.11 has been suggested as contributing to the pathogenicity of this microdeletion syndrome. We report a three-year-old boy with the 16p13.11 microdeletion syndrome, identified on array CGH, and describe his clinical phenotype, thereby adding to the existing literature on this newly-described microdeletion syndrome. We discuss the function and potential relevance of the genes in this region with regards to the features described in this condition. © 2011 Elsevier Masson SAS.

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