Introduction
Takenouchi-Kosaki syndrome (TKS) is a rare congenital disease caused by a de novo heterozygous mutation, NM_001039802.2:c.191A>G:p.(Tyr64Cys) in the CDC42gene, a gene known to play a pivotal role in cell cycle regulation.1,2 CDC42 functions in multiple organs in the cardiovascular, genitourinary, respiratory, nervous, and immune systems. This explains the following clinical features of TKS: macrothrombocytopenia, developmental delay, dysmorphic facial features, deafness, and other medical conditions, such as hypothyroidism, immunodeficiency, lymphedema, and camptodactyly, depending on the case.3-6 Previously, we reported a case of autoimmune haemolytic anaemia (AIHA) with TKS,5 which was the first reported comorbid case. Little is known about treatment for macrothrombocytopenia associated with TKS,7 and therefore, thrombocytopenia has been treated with platelet transfusion only when patients exhibit severe hemorrhage. Splenectomy has been a contraindication for treating inherited thrombocytopenia8; however, in this case, we decided to perform splenectomy to break the vicious cycle of intractable hypersplenism and AIHA, which required repetitive red blood cell transfusions.
After splenectomy, we unexpectedly observed an improvement in thrombocytopenia in addition to AIHA, which is a novel effect of splenectomy for thrombocytopenia in TKS.