A novel DLL4 missense mutation in a Chinese patient with Adams-Oliver syndrome

To the Editor:Adams-Oliver syndrome (AOS,including 6 types) was initially reported in a three-generation family by Adams and Oliver in 1945,[1] with an estimated incidence of 1 in 225,000 live births.[2] Approximately 84% of AOS patients have terminal transverse limb defects,including amputations,syndactyly,brachydactyly,or oligodactyly.