Prevalence of α1-antitrypsin deficiency alleles PI*S and PI*Z worldwide and effective screening for each of the five phenotypic classes PI*MS, PI*MZ, PI*SS, PI*SZ, and PI*ZZ: a comprehensive review.

Genetic epidemiological studies on the prevalence and numbers of individuals with α1-antitrypsin deficiency in each of 97 countries worldwide were used to estimate the numbers in each of the five following phenotypic classes: PIMS, PIMZ, PISS, PISZ, and PIZZ. These 97 countries were then grouped into 10 major geographic regions to make it possible to compare the numbers in each of these five phenotypic classes in immediately adjacent countries. Such groupings also make it possible to review the spread of the PIS and PIZ alleles from one major geographic grouping to another in the world as well as the spread of these two deficiency alleles within a major geographic region. The data in the 10 tables on the numbers in each of the five phenotypic classes in the countries in the same geographic region as well as the prevalence of the PIS and PIZ alleles in countries in the same geographic region provide a novel database for the identification of large numbers of individuals in a given phenotypic class. The database also provides useful information for the identification of countries with high numbers of PIZZ individuals for augmentation therapy within a given geographic region.