Alpha 1 antitrypsin polymorphism in the Tunisian population with special reference to pulmonary disease

The study investigated alpha 1 antitrypsin (AAT) gene polymorphism in the Tunisian population. We aimed to analyze the correlation between Pi polymorphism and the risk of developing chronic obstructive pulmonary disease (COPD).

We focused our study on two samples originating from the Tunisian centre: 318 healthy controls and 90 patients suffering from COPD. Data analysis was investigated by AAT level quantification, serum isoelectric focusing (IEF) and RFLP-PCR performed with PiS and PiZ allele specific primers.

We calculated PiM1, PiM2, PiM3, PiS and PiZ allele frequencies in patients and controls. The difference in allele frequencies is significant only for the PiM2 allele (P=0.00378). In COPD patients, we note the presence of PiZ allele. This allele mainly observed in European populations, is rare in sub-Saharian populations and not described in North Africa.

PiZ allele is found in COPD sample and never in Tunisian controls. However, no significant difference in PiZ allele frequency between patients and controls can be concluded. PiM2 allele, which is considered as "normal" variant can be associated with COPD risk.