People with the MI genotype are genetic An 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. More of the I mutation. The I mutation results in a reduced quantity of Alpha-1 protein in the blood and is believed to be risk-raising when combined with another Alpha-1 mutation. The M allele is normal. The MI genotype has not been associated with an increased risk for lung or liver disease. More information about genotypes involving the I mutation may be known in the future.Alpha-1 at MUSC – Genetic Counseling
Because Alpha-1 is a genetic condition, your result means that your relatives are at increased risk to also have abnormal alpha-1 genes. We encourage you to make your family members aware of the condition in your family and the availability of testing. In order for your relatives to have accurate testing the test must look for the I mutation. Reproductive partners of people with abnormal alpha-1 genes should also be offered testing to assess risk to children.
I: Likely S-like
What is Your Phenotype and What Does it Mean? – Kimberly Foil, MS, CGC, Genetic Counseling Program, Alpha-1 Foundation; Division of Medical term referring to the lungs. More and Critical Care Medicine, Medical University of South Carolina (MUSC)
- Moderate deficiency allele
- Not known to accumulate in the liver