Bernard-Soulier syndrome

What it is

Bernard-Soulier syndrome is a defect in platelet plug formation. The defect is in GpIb, so it is an adhesion problem: the platelet cannot bind to vWF. Inheritance is autosomal recessive, and the platelets it makes are large. It is set against Glanzmann thrombasthenia, which is also autosomal recessive but whose defect is in GPIIb/IIIa, an aggregation problem, with normal-sized platelets.

How it presents

Platelet abnormalities give microhemorrhage: mucous membrane bleeding, epistaxis, petechiae, purpura, an increased bleeding time, and possibly a decreased platelet count. In Bernard-Soulier syndrome the usual picture is mucocutaneous bleeding, menorrhagia and bruising, and it can show up as a prolonged history of easy bruising in a young child with an unremarkable physical examination and a normal coagulation profile.