alpha 1-Antitrypsin (Pi) types and subtypes in the Tyrolean population

Area of Science:

• Genetics
• Biochemistry
• Pediatric Hepatology

Background:

• Infantile liver disease is associated with alpha-1-antitrypsin (AAT) deficiency, specifically the Pi ZZ phenotype.
• Nine cases of infantile liver cirrhosis or hepatopathy linked to the Pi ZZ phenotype were observed at the Children's Hospital of the University of Innsbruck.
• Understanding AAT Pi type distribution in the Tyrolean population is crucial for assessing genetic predisposition.

Purpose of the Study:

• To determine the distribution of alpha-1-antitrypsin (AAT) Pi types and PiM subtypes in the Tyrolean population.
• To establish baseline genetic data for AAT deficiency in Tyrol, Austria.

Main Methods:

• Analysis of AAT Pi types and PiM subtypes in 868 apparently healthy blood donors from various regions of Tyrol.
• Isoelectric focusing (IEF) technique employed for the classification of AAT Pi types.

Main Results:

• The frequency of the alpha-1-antitrypsin (AAT) PiZ allele in the Tyrolean population was determined to be 0.0138.
• This frequency aligns with ranges observed in other Middle European populations.
• Frequencies for PiM subtypes were: PiM1 = 0.7062, PiM2 = 0.1480, and PiM3 = 0.1037. The PiS allele frequency was 0.0225, with rare alleles at 0.0058.

Conclusions:

• The determined frequency of the AAT PiZ allele in Tyrol is comparable to other Middle European populations.
• The findings provide essential genetic data on AAT Pi types in Tyrol, relevant for understanding the prevalence of AAT deficiency-related liver diseases.