Impaired platelet function in Hermansky-Pudlak syndrome associated with novel mutations in HPS3, HPS6 and HPS8 genes

We report three unrelated cases of Hermansky-Pudlak syndrome (HPS) characterized by novel mutations in HPS3 (compound het-erozygosity for c.1457G>A and c.1813G>T), HPS6 (homozygous c.210_211insGGGCC), and BLOC1S3 (homozygous c.299dupC)genes. No spontaneous bleeding tendency was observed despite the presence of several platelet function abnormalities. Screening testwith PFA-100 failed to detect the abnormality. This report confirms the pattern of low bleeding risk in patients with rare HPS and theneed for detailed platelet function studies despite normal hemostatic screening tests.