Analysis of MECOM in TRS5 and her family. (A) Pedigree of family 2. Black on the left represents pancytopenia, black on the upper right represents radioulnar synostosis, and black on the lower right represents clinodactyly of the fifth finger of hands. P indicates the proband (TRS5). (B) Radiographs of the individuals with c.2208-4A>G variants. Left, bilateral clinodactyly of the fifth fingers of the brother of TRS5 (II-1). Lower left, PIP joint fusion of bilateral second toes were suspected. Fusions of the DIP joint of the fourth and fifth toes on the left foot and third, fourth, and fifth toes on the right foot of the father of TRS5 (I-2). The incidence of DIP fusion in the Japanese population is 72.5% in the fifth toe, 11.9% in the fourth toe, and 0.8% in the third toe.17 Right, bilateral radioulnar synostosis in the father of TRS5 (I-2). (C) The c.2208-4A>G variant in MECOM in TRS5 and her family. The variant was identified in TRS5 as well as her brother and father. (D) A schema showing the splicing of wild-type (left) and mutant (right) RNA. Bold letters show GT-AG consensus nucleotides. (E) cDNA analysis revealed the presence of the in-frame insertion in TRS5 as well as her father and brother. PCR primer set 2 was used for TRS5 and her brother, and PCR primer set 3 was used for her father. cDNA, complementary DNA; DIP, distal interphalangeal; PCR, polymerase chain reaction; PIP, proximal interphalangeal.