Early research shows a one-time gene therapy has potential for addressing both the liver and lung disease that patients with alpha-1 antitrypsin deficiency (AATD) face. Early research shows a one-time gene therapy has potential for addressing both the liver and lung disease that patients with alpha-1 antitrypsin deficiency (AATD) face. ... A groundbreaking clinical trial has achieved what researchers call a landmark moment in medicine: the first-ever precise correction of a disease-causing genetic mutation in patients with alpha-1 antitrypsin deficiency (AATD), a rare inherited disorder that can lead to early-onset emphysema and liver disease. In addition, the treatment achieved levels of functional protein above the protective therapeutic threshold, a key milestone for potential treatment success. "This landmark result represents the first clinical evidence of precise correction of a disease-causing mutation by rewriting the genetic code," said John Evans, chief executive officer of Beam Therapeutics, in a news release. A deficiency in this protein can lead to chronic obstructive pulmonary disease and may also cause the liver disease cirrhosis. The study demonstrated that a single intravenous infusion could potentially transform treatment for patients with the most severe form of AATD. The research focused on patients with the PiZZ genotype who have two copies of a mutated gene that causes alpha-1 antitrypsin to misfold and accumulate in the liver, leaving the lungs unprotected from damage. About 30% of patients have liver disease, including fibrosis and cirrhosis. About 80% of patients have lung disease, including early-onset emphysema, chronic cough, and shortness of breath. In the trial, patients received varying doses of the experimental therapy, with the highest dose group showing dramatic improvements.