This mutation causes the liver to produce an abnormal form of the alpha-1 antitrypsin protein, which is then deposited in the liver cells instead of being released into the bloodstream to protect the lungs.

The accumulation of the abnormal protein in the liver cells can lead to liver damage and increase the risk of developing liver disease, such as cirrhosis and liver cancer. Additionally, the lack of functional alpha-1 antitrypsin in the bloodstream can allow enzymes called proteases to attack and damage the lung tissue, leading to respiratory problems such as emphysema and chronic obstructive pulmonary disease (COPD).

It also leads to Necrotizing panniculitis (Weber–Christian disease), c-ANCA positive vasculitis (e.g., Wegener granulomatosis), Bronchiectasis without other etiology