[Congenital thrombocytopenia].

Congenital thrombocytopenia is a group of heterogeneous disorders caused by mutations in the responsible genes that play crucial roles in normal megakaryopoiesis and subsequent platelet production. The diagnosis of congenital thrombocytopenia is clinically necessary to distinguish it from immune thrombocytopenia and select the appropriate therapeutic modalities. The number of responsible genes reported so far is up to 56, and data on their targeted sequencing and subsequent exome sequencing analysis are available in Japan. Here, we report the disease outlines, disease classification based on platelet sizes (small, normal, large, and giant platelets), disease descriptions, consultation system, list of responsible genes, therapeutic options, and follow-up system for congenital thrombocytopenia.