agenesis
/əˈdʒɛnɪsɪs/Definitions
1. noun
The congenital absence of an organ or part.
“The baby was born with agenesis of the kidney, which required immediate medical attention.”
2. noun
A developmental abnormality resulting in the absence of a part or organ.
“The researchers studied the effects of agenesis on the development of the brain in fetuses.”