!1-Antitrypsin: protein, gene, and important mutations

The !1-antitrypsin protein has three oligosaccharide
side chains at positions 46, 83, and
247. The protein is highly polymorphic because
of differences in the amino acid sequence and in
carbohydrate side chains. The reactive site is located
at position 358/359 (methionine/serine).
Clinically, the most important mutations affect
codons 213 (PiZ), 256 (PiP), 264 (PiS), 342 (PiZ),
and 357 (Pi[Pittsburgh]). The gene contains variant
restriction enzyme sites, which can be used
for reliable diagnosis. Today the diagnosis is
often made using the PCR reaction.