What initial laboratory investigations should be performed in a patient suspected of having an inherited bleeding disorder?

In a patient suspected of having an inherited bleeding disorder, initial laboratory investigations should include a full blood count (FBC) to assess platelet number and morphology, prothrombin time (PT), activated partial thromboplastin time (aPTT), and fibrinogen level to evaluate the coagulation cascade and exclude acquired coagulopathies NICE NG88. Additionally, specific assays such as von Willebrand factor antigen and activity tests, and factor VIII and IX levels, are important to identify common inherited bleeding disorders like von Willebrand disease and haemophilia NICE NG88. Platelet function screening tests, such as platelet function analyser (PFA-100) or light transmission aggregometry, may be used to detect platelet function defects NICE NG88. Recent literature emphasizes that while these initial tests are essential, they have limitations in sensitivity and specificity, and high-throughput sequencing can provide a more comprehensive diagnosis by identifying genetic variants responsible for inherited bleeding and platelet disorders Ver Donck et al. 2020. Therefore, after initial screening, referral for specialised haemostasis testing and genetic analysis should be considered to confirm diagnosis and guide management Ver Donck et al. 2020.