Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Alpha-1 Antitrypsin Deficiency ?
    ### Response:
    Alpha-1 antitrypsin (AAT) deficiency usually is diagnosed after you develop a lung or liver disease that's related to the condition.
                
Your doctor may suspect AAT deficiency if you have signs or symptoms of a serious lung condition, especially emphysema, without any obvious cause.
    