This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bilirubin Metabolism, Subject name: Pathology
a-1 antitrypsin deficiency is associated which of the following? 
Select and explain. 
A. Cirrhosis, B. Neonatal hepatitis, C. Pulmonary emphysema, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: a1-Antitrypsin deficiency Autosomal recessive disorder of protein folding marked by very low levels of circulating a1-Antitrypsin (a1AT). Neonatal hepatitis with cholestatic jaundice appears in 10% to 20% of newborns with the deficiency. In adolescence, presenting symptoms may be related to hepatitis, cirrhosis or pulmonary disease (emphysema).