Estimates of PI*S and PI*Z Alpha-1 antitrypsin deficiency alleles prevalence in the Caribbean and North, Central and South America.

Background: AAT deficiency is not a rare disease, but one of the most common congenital disorders increasing susceptibility of individuals with this deficiency to both lung and liver disease as well as other several adverse health effects. Studies to develop accurate estimates of the magnitude of this genetic disorder in any given country is critical for the development of screening programs for detection, diagnosis, and treatment of those individuals and/or families at risk. In the present study, estimates of the prevalence of the two major deficiency alleles PI S and PI Z were estimated for 25 countries in the Caribbean and North, Central, and South America to supplement our previous studies on 69 countries worldwide.

Method: Using data on the prevalence of the two most common deficiency alleles PI S and PIZ in the mother countries that provided the majority of immigrants to these 25 countries, as well as genetic epidemiological studies on various genetic subgroups indigenous to the Caribbean and North, Central and South America it was possible to develop new formulas to estimate the numbers in each of five phenotypic classes, namely PI MS, PI MZ, PI SS, PI SZ and PI ZZ for each country.

Results: When these 25 countries were grouped into six different geographic regions, the present study demonstrated striking differences when comparisons were made in numeric tables, maps and figures. Highly significant numbers of individuals at risk for AAT Deficiency were found in both the European, Mestizo and Mulatto populations for most of the 25 countries studied in the Caribbean and North, Central and South America.

Conclusions: Our studies demonstrated striking differences in the prevalence of both the PIS and PIZ alleles among these 25 countries in the Caribbean and North, Central and South America and significant numbers of individuals at risk for adverse health effects associated with AAT Deficiency in a given country. When these data are added to the results from our earlier studies on 69 countries, we now have data on AAT Deficiency in 94 of the 193 countries worldwide listed in the CIA FactBook.