Alpha 1-antitrypsin phenotypes in Canadian Metis

Area of Science:

• Genetics
• Anthropology
• Biochemistry

Background:

• Alpha 1-antitrypsin (AAT) deficiency is a genetic condition that can lead to lung and liver disease.
• Population-specific AAT allele frequencies are important for understanding genetic diversity and disease risk.
• Previous studies have documented AAT phenotypes in various Indigenous populations globally.

Purpose of the Study:

• To determine the Alpha 1-antitrypsin (AAT) phenotype and genotype frequencies in a Metis population from northern Saskatchewan.
• To compare these frequencies with those reported in other Indigenous North American and circumpolar populations.

Main Methods:

• Serum samples were collected from 344 individuals of Metis ancestry residing in an isolated northern Saskatchewan community.
• Alpha 1-antitrypsin (AAT) phenotyping was conducted using established laboratory techniques.
• Phenotype and gene frequencies were calculated based on the observed results.

Main Results:

• Only PiM and PiMZ phenotypes were detected in the studied Metis population.
• The observed phenotype frequencies were 98.5% for PiM and 1.5% for PiMZ.
• The calculated gene frequencies were 0.993 for PiM and 0.007 for PiZ.

Conclusions:

• The genetic profile for Alpha 1-antitrypsin (AAT) in this northern Saskatchewan Metis community is characterized by a high frequency of the PiM allele and a very low frequency of the PiZ allele.
• These findings align with AAT allele frequencies observed in other North American Indigenous groups, such as the Igloolik Eskimos, as well as in Finnish and Norwegian Lapps.
• The low prevalence of non-M AAT phenotypes suggests a potentially lower genetic predisposition to AAT deficiency-related diseases within this specific Metis population compared to populations with higher frequencies of PiZ or other deficient alleles.