RTTN and Immunodeficiency: In the presenting study, besides MBP, 46,XX,del(18)(q21.3) caused the loss of 16 morbid genes including NEDD4L, MALT1, RAX, LMAN1, CCBE1, MC4R, PIGN, TNFRSF11A, BCL2, SERPINB7, SERPINB8, RTTN, CYB5A, TSHZ1, CTDP1, TXNL4A, and 46,XX,r(18)(p11.32q21.3) were caused additional loss of LPIN2 and SMCHD1. The phenotypes were related with immunodeficiency, growth abnormality, malformation, neurologic, cardiovascular, hematological, cutaneous, skeletal disorders, etc (Summarized in S8 Table).