Scientists have identified a new mutation in the gene that causes the inherited disease known as Alpha-1 Antitrypsin Deficiency (Alpha-1), which affects roughly one in 2,500 people of European descent.
Alpha-1 can lead to serious lung disease in adults, or liver disease at any age.
The finding extends understanding of Alpha-1 at the molecular level, potentially leading to new drug development and better diagnostic tools.
Dr Darren Saunders from Sydney's Garvan Institute of Medical Research and Professor Vanessa Hayes, from the J. Craig Venter Institute in San Diego, published their results in the international journal PLOS One, now online.
In healthy people, Alpha-1 Antitrypsin is a molecule, or 'protein', made in the liver then secreted into the blood. It helps keep the lungs healthy by blocking an enzyme that causes tissue breakdown.
The genetic mutations that trigger Alpha-1 disease cause the Alpha-1 Antitrypsin protein to accumulate in the liver, rather than being secreted into the blood. That in turn leads to tissue breakdown in the lungs.
Alpha-1 is often first diagnosed as asthma or smoking-related Chronic Obstructive Pulmonary Disease (COPD). Typically, people experience symptoms like shortness of breath, wheezing, recurrent chest colds and allergies. They might also develop unexplained liver disease.