This guideline replaces the previous British Committee for Standards in Haematology guideline published in 2011 on laboratory diagnosis of heritable disorders of platelet function.1 The remit has been expanded to include clinical diagnosis and heritable thrombocytopenia under the overarching term heritable platelet disorder (HPD). Acquired disorders such as immune thrombocytopenia and drug-induced platelet dysfunction are not covered.
Since the previous guideline there have been significant advances in the clinical assessment of HPD. For example, bleeding assessment tools (BATs) have been developed to standardise clinical evaluation and provide a quantitative analysis of bleeding symptoms.2 A major laboratory advance has been in the use of high-throughput sequencing (HTS) which is now available in routine clinical practice in the UK. As a result there has been a large increase in distinct HPD with a better understanding of their underlying molecular basis and clinical effects.3 Previously there were five categories of HPD captured in the National Haemophilia Database (NHD) of which three were distinct disorders: Glanzmann thrombasthenia, Bernard–Soulier syndrome and platelet-type pseudo-von Willebrand disease. These have now been replaced by the single HPD overarching category with several sub-categories covering nearly 50 distinct disorders (http://www.ukhcdo.org/nhd/). While these are individually rare disorders, collectively HPD comprise 10% of registered cases in the NHD, the fourth most common group of disorders after von Willebrand disease, haemophilia A and factor XI deficiency.4
The International Society on Thrombosis and Haemostasis (ISTH) has produced guidance on the order in which laboratory assays may be used to investigate platelet function disorders5 and consenting of patients for genomic testing.6 There are also North American guidelines for laboratories on light transmission aggregometry.7 However, there remains a need for guidance for clinicians and scientists involved in the diagnosis of these disorders that is up to date and specific to UK practice.
Declaration of Interests
The BSH paid the expenses incurred during the writing of this guidance. None of the authors had conflicts of interest to declare. All authors have made a declaration of interests to the BSH and Task Force Chairs which may be viewed on request.