Apolipoprotein E and Alzheimer's disease: ethnic variation in genotypic risks

Ann Neurol. 1995 Feb;37(2):254-9. doi: 10.1002/ana.410370217.

Abstract

The presence of the apolipoprotein epsilon 4 (apo epsilon 4) allele significantly increases the risk of Alzheimer's disease. Whether this is due to biological effects of the apo epsilon 4 protein or reflects linkage disequilibrium with an as yet unidentified Alzheimer's disease susceptibility gene is of critical importance. In a community study in northern Manhattan we found a fivefold increase in the risk of Alzheimer's disease among African-Americans, Hispanics, and whites homozygous for apo epsilon 4. Overall, the risk between Alzheimer's disease and apo epsilon 4 heterozygosity was also increased by twofold, but the association was somewhat weaker for African-Americans than for Hispanics and whites. In contrast, the apo epsilon 2/epsilon 3 genotype was associated with an eightfold increased risk of Alzheimer's disease in African-Americans but it was associated with reduced risk in whites. Variability in the strength and type of association between Alzheimer's disease and the apo E polymorphisms in the three ethnic groups could not be fully explained by age differences. The allelic frequency of apo epsilon *4 was significantly higher in patients than control subjects in all ethnic groups at age 70 or younger, reflecting the higher proportion of apo epsilon 4 homozygotes, but this difference diminished with increasing age. The allelic frequency of apo epsilon *2 for African-Americans and Hispanics, but not whites, was significantly higher in patients than control subjects, but only after age 70.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • African Continental Ancestry Group / genetics
  • Aged
  • Aged, 80 and over
  • Alleles
  • Alzheimer Disease / ethnology*
  • Alzheimer Disease / genetics
  • Apolipoproteins E / genetics*
  • Case-Control Studies
  • European Continental Ancestry Group / genetics
  • Female
  • Genotype
  • Hispanic Americans / genetics
  • Humans
  • Linkage Disequilibrium
  • Male
  • Middle Aged
  • Odds Ratio

Substances

  • Apolipoproteins E