How Do You Get It?

Since Alpha-1 Antitrypsin Deficiency is an inherited disorder, it occurs when both parents pass on a abnormal copy of the gene to their child. A father and mother who are both carriers (MZ) could expect to have a 50% chance of having a carrier, and a 25% chance of having either a healthy or a deficient child. With the birth of each child, the same percentages apply. Therefore, it is entirely possible for a MZ father and a MZ mother to have four children, all of which are ZZ or all of which are MM. Or on the other hand, it is possible for this same father and mother to have 1 ZZ child, 2 MZ child and 2 MM child as the percentages imply. If one parent has the ZZ genotype, and the other has two normal copies of the gene (MM), all of their children will have the MZ genotype.

 

Risk Associated with Common Genetic Variants

Normal (MM)  

Does not have the disorder; does not carry any abnormal AAT alleles.

Carrier (MZ)                 

May get disease symptoms and does carry an abnormal AAT allele.

Carrier (MS)

It is unclear whether there is a risk for getting disease symptoms but does carry an abnormal AAT allele (most studies do not show an increased risk for disease).

Alpha-1 (SZ) or (ZZ)

Could get disease and does carry two abnormal AAT alleles.

Alpha-1 (SS)

It is unclear whether there is a risk for getting disease symptoms but does carry two abnormal AAT alleles (most studies do not show an increased risk for disease). 


Learn about who should get tested.