alpha1-Antitrypsin (AT) is the principal serum inhibitor of proteolytic enzymes such as neutrophil elastase.
AT can exist as over 90 different genetically determined variants known as the Pi system : the three most important variants are type M (90% of population) and types S and Z. two of the commoner abnormal variants.
Homozygotes of type Z have a severe reduction in the serum AT concentration and may develop pulmonary emphysema or hepatic cirrhosis.
Heterozygotes of type SZ have a less severe reduction in serum AT concentration and the association with clinical disease is less clear.
The S and Z variants are found mainly among those of European stock.
The gene frequency for Pi type Z is highest on the north-western seaboard of the continent and the mutation seems likely to have arisen in southern Scandinavia.
The distribution of type S is quite different ; the gene frequency is highest in the Iberian peninsula and the mutation is likely to have arisen in that region.
A population survey for determining the number of type Z homozygotes in a given community is important for planning purposes now that AT replacement therapy is potentially available.
Mots-clés Pascal : Déficit, alpha1-Antitrypsine, Emphysème, Poumon, Europe, Association morbide, Epidémiologie, Homme, Déterminisme génétique, Glycoprotéine, Métabolisme pathologie, Maladie héréditaire, Enzymopathie, Appareil respiratoire pathologie, Poumon pathologie
Mots-clés Pascal anglais : Deficiency, alpha1-Antitrypsin, Emphysema, Lung, Europe, Concomitant disease, Epidemiology, Human, Genetic determinism, Glycoproteins, Metabolic diseases, Genetic disease, Enzymopathy, Respiratory disease, Lung disease
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0247194
Code Inist : 002B11D. Création : 11/09/1998.