The common polymorphism of apolipoprotein E: geographical aspects and new pathophysiological relations.
Apolipoprotein E (apoE) has important functions in systemic and local lipid transport, but also has other functions. The gene (APOE) shows a common polymorphism with three alleles--APOE*2, APOE*3, and APOE*4. Their frequencies vary substantially around the world, but APOE*3 is the most common almost everywhere and is often considered to be the ancestral or "wild-type" allele for that reason. However, there are several arguments for APOE*4 being the ancestral allele. But then, why has APOE*3 become so frequent? And why has APOE*4 not become extinct? The proportion of APOE*4 carriers increases from only 10-15% in southern Europe to 40-50% in the north. The gradient may be a trace of the demic expansion of agriculture that began about 10,000 years ago, but it may also reflect the possibility that APOE*4 carriers are less likely to develop vitamin D deficiency. The common APOE polymorphism is associated with varying risk of cardiovascular disease and Alzheimer's disease, but other interesting aspects may emerge in the future.
Gerdes
Lars Ulrik
LU
Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus Amtssygehus, Aarhus, Denmark. ulrik.gerdes@dadlnet.dk
D001057:Apolipoproteins E / Q000235:genetics*; D005787:Gene Frequency; D005828:Genetics, Population; D005838:Genotype; D005843:Geography; D006801:Humans; D011110:Polymorphism, Genetic / Q000235:genetics*; D014811:Vitamin E Deficiency / Q000235:genetics
D001057:Apolipoproteins E