The apolipoprotein E polymorphism in Greenland Inuit in its global perspective

Area of Science:

• Human Genetics
• Population Studies
• Biochemistry

Background:

• Apolipoprotein E (apoE) plays a crucial role in lipoprotein metabolism.
• Understanding apoE genotype frequencies in diverse populations is vital for genetic and health research.
• Previous studies have indicated variations in apoE allele distribution across different ethnic groups.

Purpose of the Study:

• To determine apolipoprotein E (apoE) genotype frequencies in Inuit populations from Greenland.
• To investigate the association between apoE genotypes and plasma lipoprotein-related variables in Inuit individuals.
• To contribute to a global understanding of apoE allele distribution and its evolutionary implications.

Main Methods:

• Genotyping of apolipoprotein E (apoE) alleles in Inuit samples from Nuuk (n=100) and Ammassalik (n=78).
• Analysis of plasma lipoprotein-related variables, including HDL cholesterol, triglycerides, non-HDL cholesterol, and apolipoprotein B.
• Comparison of allele frequencies with existing data from other aboriginal populations to create a world map.

Main Results:

• The epsilon 2 allele was absent in the Ammassalik Inuit sample; the epsilon 4 allele frequency was high (approx. 23%).
• Inuit individuals with the epsilon 4 genotype exhibited higher mean levels of triglycerides, non-HDL cholesterol, and apolipoprotein B compared to epsilon 3 epsilon 3 genotypes.
• Combined data and a world map of apoE allele frequencies were generated, suggesting epsilon 4 may be the ancestral allele.

Conclusions:

• The Greenlandic Inuit population exhibits distinct apolipoprotein E (apoE) allele frequencies, notably a high prevalence of epsilon 4.
• The epsilon 4 allele is associated with altered lipid profiles in this population, consistent with findings in other groups.
• The study provides insights into the evolutionary history of the apoE polymorphism, supporting the hypothesis of epsilon 4 as an ancestral allele.