CD99 and Timothy syndrome: Fourteen of these 16 DEGs between TS and KS are located on the X chromosome, 8 of which (ZBED1, ASMTL, AKAP17A, CD99, CSF2RA, DHRSX, P2RY8, and SMC1A) are located in the pseudo‐autosomal 1 region of the X or Y chromosome (PAR1) (Figure 2a), owing to the presence of the extra or missing X chromosome, characteristic of KS and TS.