• Register
  • Login
  • Bookmark this page!
Skip Navigation LinksHome Page    >    Planning a pregnancy    >    Alpha-1-antitrypsin deficiency
 
 
Pregnancy links...
Health links...
Genetics links...
Medical links...
Autism links...
Other links...
 

Alpha-1-antitrypsin deficiency

Alpha-1-antitrypsin is a protease inhibitor, deficiency of which is associated with emphysema and liver disease. In most cases the disease is not severe and only rarely leads to liver failure.

Deficiency of alpha-1-antitrypsin activity is associated with several of the electrophoretic variants of serum alpha-1-antitrypsin. The normal enzyme variant is called M. The variants that are associated with marked emphysema and liver disease are called S and Z. The Z type is the least common, but a child who carries two alleles/genes of this type is at risk to have the most severe form of the disease.

Inheritance pattern

Autosomal recessive.

Penetrance

Incomplete.

Associated features that can be demonstrated in tests performed during pregnancy

There are no specific ultrasound signs or associated defects.

What is the risk of recurrence in a subsequent pregnancy?


For a couple who has already had an affected child, the risk is 25% in every subsequent pregnancy.

This also applies to a couple where both partners have been found to carry the Z (or S) allele.

When only one parent carries the Z allele (or S allele), there is no risk that any of their offspring will have the disease.

Molecular genetic information

Gene, Location

The protein is encoded by a gene, PI, that is located on the distal long arm of chromosome 14q31-32.

Genetic testing

Diagnostic testing

A direct test can be performed to identify the abnormal variants Z and S at the DNA level. See: Testing the disease-causing gene for mutations that are common in a specific ethnic group - autosomal recessive diseases.

Carrier testing

All ethnic groups are similarly affected. The carrier frequency in the healthy Jewish population is 1:80. Two major variant forms, Z and S, are associated with Alpha-1-antitrypsin deficiency, and both can be tested relatively easily.

Due to the relatively rarity of this disease and especially since most cases are treatable adult diseases, general population screening is not justified.

See also: "Introduction to population DNA screening for autosomal recessive diseases such as Cystic fibrosis and others".

Fetal testing

There is usually no indication to test the fetus for this disease.
 
Haven't found what you're looking for? Search for it here:   
Comments (1)


Monday, February 16, 2015 3:39 AM
(1) Prince  says:


Essay

It grabs solid process also dedication for your duty to be termed as the elite write my Essay State. We acquire worked on this utility for the abide trio years studying furthermore upgrading our abilitys. We do nevertheless value the class.





Leave a Comment
Name
Email (will not be published)
Website (optional)
Subject
Your Comment

Line and paragraph breaks are automatic.

Please type the characters you see in the picture:


All content Copyright © 2009-2011, Genetics of Pregnancy Encyclopedia Corporation. All rights reserved.