Alpha-1 antitrypsin deficiency is inherited in families in an autosomal codominant pattern. Codominant inheritance means that two different variants of the gene (alleles) may be expressed, and both versions contribute to the genetic trait. There is no recessive Alpha gene as the term "carrier" would imply.
In order to be classified as having Alpha-1, an individual must inherit at least one abnormal AAT genes. Individuals who have one abnormal AAT gene and one normal AAT gene are sometimes referred to as heterozygotes or "carriers."
Many of the risk factors that can lead to disease in Alphas are known, and the management of these risk factors is one of the most important ways in which individuals with Alpha-1 can directly affect the quality of their lives. Recently, there has been a growing appreciation that individuals who have been identified as carriersAn Alpha-1 Carrier is a person who has one normal ATT gene (M) and one defective AAT gene (usually S or Z). It does NOT mean you cannot get sick. of the Alpha-1 gene also may be at increased risk for disease development. Therefore, limiting exposure to environmental risk factors is important for these individuals as well.
Introduction to Alpha-1 – Big Fat Reference Guide, AlphaNet
If a person inherits one M gene and one Z gene or one S gene ('type PiMZ' or 'type PiMS'), that person is a carrierAn Alpha-1 Carrier is a person who has one normal ATT gene (M) and one defective AAT gene (usually S or Z). It does NOT mean you cannot get sick. of the disorder. While such a person may not have normal levels of alpha-1 antitrypsin, there should be enough to protect the lungs. However, carriersAn Alpha-1 Carrier is a person who has one normal ATT gene (M) and one defective AAT gene (usually S or Z). It does NOT mean you cannot get sick. with the MZ alleles have an increased risk for lung disease, particularly if they smoke.
Learning About Alpha-1 Antitrypsin Deficiency (AATD) - National Human Genome Research Institute
This video is an informational talk by Dr. Sandhaus from 2015. It covers the health risks to carriersAn Alpha-1 Carrier is a person who has one normal ATT gene (M) and one defective AAT gene (usually S or Z). It does NOT mean you cannot get sick., knowledge gaps, and evidence for and against various treatments for carriersAn Alpha-1 Carrier is a person who has one normal ATT gene (M) and one defective AAT gene (usually S or Z). It does NOT mean you cannot get sick..