RESUMEN
alpha-1 antitrypsin [AAT] deficiency results from mutations of the protease inhibitor [PI]. The AAT gene is mapped on chromosome 14 and has been associated with chronic liver disease and chronic obstructive pulmonary disease [COPD]. To determine the frequency of AAT mutations on S and Z carrier alleles in healthy Saudi individuals from Qassim Province in Saudi Arabia. A total of 158 healthy, unrelated participants from Qassim Province were recruited. They were genotyped for the two AAT-deficiency alleles, PI*S and PI*Z, using polymerase chain reaction, with primers designed throughout to mediate site-directed mutagenesis. Of the 158 subjects, 11.39% were carriers for the S mutation [i.e., had the MS genotype], whereas 2.53% were carriers for the Z mutation [i.e., had the MZ genotype]. The SZ genotype was present in 3.8% of subjects, while the homozygous genotype SS was present in 1.9% of subjects. No subjects showed the ZZ mutant genotype. Accordingly, frequency of the mutant S and Z alleles of AAT gene was 9.49% and 3.19%, respectively. The results obtained showed a high prevalence of the AAT deficiency allele in the Saudi population. This probably warrants adoption of a screening program for at-risk individuals, so that they might initiate adequate prophylactic measures