P2RY1 and Hermansky-Pudlak syndrome: In the differential diagnosis of unexplained excessive bleeding, we considered inherited platelet function disorders, including Wiskott-Aldrich syndrome, Glanzmann's thrombasthenia, Bernard-Soulier syndrome, ADP receptor defect, von Willebrand disease, idiopathic dense-granule disorder, Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, and grey platelet syndrome [7].