Alpha-1-antitrypsin (Pi) subtypes in the Spanish Basque provinces.

Alpha-1-antitrypsin subtypes were studied in resident (644) and native (222) individuals from the Spanish Basque Country. The gene frequencies were similar to those in other Spanish populations but the isolated valley of Arratia deviated significantly with increased frequencies of the M2 and M3 alleles and a decrease of the M1 allele.