Population genetics of alpha1-antitrypsin in the Netherlands. Description of a new electrophoretic variant.

Two groups of 708 healthy blood donors and 563 patients affected with chronic obstructive lung disease (C.O.L.D.) respectively, have been screened for alpha1-antitrypsin (alpha1AT) variants by electrophoresis on agarose-polyacrylamide gels at pH 4.7 and isoelectric focusing (IEF). The frequencies of the Pi (Protease inhibitor) alleles are comparable to those observed in the North European populations. As expected, the frequency of the Z gene is higher in the group of patients with C.O.L.D. Also the frequency of MZ phenotypes is higher among these patients, but in this case the difference is not statistically significant. With the aid of the electrophoretic methods described in the text we were able to detect a new electrophoretic variant (M3) showing a mobility intermediate between the M1 and the M2 phenotypes.