Apolipoprotein E polymorphism in elderly east Africans.
Current advances have shown the apolipoprotein E (APOE)-epsilon 4 allele to be highly associated with late-onset familial and sporadic Alzheimer's disease (AD) in Western populations. The association of APOE allele frequencies and dementia remain unknown in populations from developing countries. We recently initiated a project to examine APOE frequencies in non-demented and demented elderly East Africans. Blood DNA collected from two hospital-based populations showed that the APOE allele frequencies in a group of non-demented 67 Tanzanians over the age of 65 years were found to be 14% for epsilon 2, 61% for epsilon 3 and 25% for epsilon 4. By comparison, the frequency of APOE-epsilon 4 in an age-matched demented group was also 25%. Assessment of APOE genotypes in the group of elderly Kenyan subjects from Nairobi also revealed high frequencies of the epsilon 4 allele with no clear difference in frequency between demented and non-demented subjects. Our preliminary observations suggest that elderly East Africans with no apparent clinical AD possess relatively high APOE-epsilon 4 allele frequencies compared to normal ageing subjects from Western countries including African-Americans. These results appear similar to those reported in a recent study in Nigerian Africans where a lack of correlation between APOE-epsilon 4 allele frequency and Alzheimer type of dementia was noted, and imply that APOE-epsilon 4 allele may not necessarily be a risk factor in some populations of Africa.
Sayi
J G
JG
Department of Neurological Surgery (BRD5), Case Western Reserve University, Cleveland, Ohio 44106-4938, USA.
Patel
N B
NB
Premkumar
D R
DR
Adem
A
A
Winblad
B
B
Matuja
W B
WB
Mtui
E P
EP
Gatere
S
S
Friedland
R P
RP
Koss
E
E
Kalaria
R N
RN
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood / Q000235:genetics*; D001057:Apolipoproteins E / Q000235:genetics*; D016022:Case-Control Studies; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007630:Kenya; D008609:Mental Status Schedule; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D013636:Tanzania
D001057:Apolipoproteins E