What is it called when one side of the chest forms and the other doesn't?

Answer 1

When an organ doesn't form at all it is called aplasia. When it forms but is abnormally small it is called hypoplasia. So one form of the chest not forming properly would be called pulmonary (lung) hypoplasia.

Aplasia are generally very rare and usually fatal. Hypoplasias can be mild to extremely serious or fatal.

Answer 2

Weird is what it's called. sorry if you consider me being insensitive