What is Alpha-1?
Alpha-1 Antitrypsin Deficiency (Alpha-1) is a condition that is passed from parents to their children through their genes. This condition may result in serious lung and/or liver disease at various ages in life. For each trait a person inherits, there are usually two genes and one gene comes from each parent. People with Alpha-1 have received two defective alpha-1 antitrypsin genes. One defective gene came from their mother and one from their father. There are many types of defective alpha-1 antitrypsin genes. The most common abnormal genes are called S and Z. Normal genes are called M. A person who does not have Alpha-1 will have two M genes (MM). People identified with Alpha-1 most commonly have two Z genes (ZZ). Current evidence suggests there are up to 100,000 people with Alpha-1 (ZZ) in the United States. Another deficient gene combination is SZ, although people with this gene combination are less likely to get lung or liver problems than those with two Z genes.
Alpha-1 occurs when there is a lack of a protein in the blood called alpha-1 antitrypsin or AAT that is produced by the liver. The main function of AAT is to protect the lungs from inflammation caused by infection and inhaled irritants such as tobacco smoke. The low level of AAT in the blood occurs because the AAT is abnormal and cannot be released from the liver at the normal rate. This leads to a build up of abnormal AAT in the liver that can cause liver disease and a decrease of AAT in the blood that can lead to lung disease.
The most common signs and symptoms of disease caused by Alpha-1 are:
- Shortness of breath
- Chronic cough and sputum (phlegm) production (chronic bronchitis)
- Recurring chest colds
- Eyes and skin turning yellow (jaundice)
- Swelling of the abdomen (ascites) or legs
- Vomiting blood (from enlarged veins in the esophagus or stomach)
- Decreased exercise tolerance
- Non-responsive asthma or year-round allergies
- Unexplained liver problems or elevated liver enzymes
Alpha-1 has been identified in virtually all populations and ethnic groups. It is estimated that as many as 1 in every 2,500 Americans have Alpha-1.
Individuals with Alpha-1 may remain healthy throughout their lives. Early diagnosis and avoidance of risk factors, such as cigarette smoking, can help prevent Alpha-1 from causing disease.
An estimated 20 million people have one normal and one defective AAT gene. People with one normal gene and one defective gene (for example MZ) are called “carriers”. Carriers may pass the defective gene on to their children.
Alpha-1 can lead to lung destruction and is often misdiagnosed as asthma or smoking-related Chronic Obstructive Pulmonary Disease (COPD).
Alpha-1 is the most common genetic risk factor for emphysema and COPD.
As many as 3% of all people diagnosed with COPD may have undetected Alpha-1.
Alpha-1 can lead to liver disease. The most serious liver diseases are cirrhosis and liver cancer.
The World Health Organization (WHO), American Thoracic Society (ATS), and the European Respiratory Society (ERS) recommend that all individuals with COPD be tested for Alpha-1.
The Alpha-1 Foundation supports testing for individuals at risk for Alpha-1 Antitrypsin Deficiency. In response to concerns surrounding testing, privacy and the benefit of an early diagnosis, the Medical University of South Carolina (MUSC), with the support of the Alpha-1 Foundation, has developed a free and confidential opportunity for testing. This comes in the form of a research study called the Alpha-1 Coded Testing (ACT) Study. Additionally, the Alpha-1 Research Registry was established by the Alpha-1 Foundation at MUSC to facilitate research initiatives and promote the development of improved treatments and a cure for Alpha-1. The Registry is a confidential database made up of individuals diagnosed with Alpha-1 and individuals identified as Alpha-1 Carriers.