[Alpha 1 antitrypsin deficiency].

Alpha-1-antitrypsin (alpha-1-AT) is a potent protease inhibitor. Its deficiency predisposes to serious diseases such as "neonatal hepatitis" and "obstructive pulmonary emphysema". Due to the existence of multiple codominant alleles at one single locus, there are several genetic variants from alpha-1-AT. In homozygous persons the protease inhibitor type (Pi type) MM is prevailing, in heterozygous persons the Pi types MZ and MS. So far one knows at least 24 different alleles. Their phenotypes differ as well in their electrophoretic position as in the protein concentration of the serum. Pi type MM guarantees a normal concentration of alpha-1-AT in the serum, whereas Pi type ZZ causes of serious alpha-1-AT deficiency which bears a particularly high risk of disease.