Existing from birth (6)
(Other definitions for innate that I've seen before include "Congenital" , "not needing to be taught" , "Inherent or inborn" , "Inherent, natural" , "quite natural" .)
'existing from birth' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for inborn that I've seen before include "Native" , "Innate, natural" , "that's natural" , "Congenital" , "Normally existing at birth" .)