In the present report, we showed that Takenouchi-Kosaki syndrome is a clinically recognizable condition characterized by a combination of macrothrombocytopenia, intellectual disability, sensorineural hearing loss with structural brain abnormalities, camptodactyly, and frequent infections and decreased CD19-positive cells. Here, CD19 is linked to macrothrombocytopenia-lymphedema-developmental delay-facial dysmorphism-camptodactyly syndrome.