Apolipoprotein E4 allele frequency, ischemic cerebrovascular disease, and Alzheimer's disease.

Stroke welcomes Letters to the Editor and will publish them, if suitable, as space permits. They should not exceed 1, 000 words (excluding references) and may be subject to editing or abridgment. Please submit Letters to the Editor in duplicate, typed double-spaced. Include an appropriate title and a fax number for the corresponding author. The American Heart Association requires that all authors sign a Copyright TransferAgreement before publication. For a copy of this agreement, contact the Stroke Editorial Office. The association of the apolipoprotein (apo) E4 allele and ischemic cerebrovascular disease has been addressed in two recent articles appearing in Stroke. 1,2 We reexamined the data in terms of estimated frequency of the three common alleles. Comparison with other published control population studies is presented in the Table. Apo E4 Population Reference No. chromosomes frequency Patients 1 138 0.16 Aged controls 1 136 0.07 Patients 2 200 0.18 Aged controls 2 200 0.18 Aged controls 3 182 0.16 Normal controls 4 2000 0.14 The apo E4 allele frequencies derived from both ischemic cerebrovascular disease studies are similar to those for all other published control groups, including the aged control series.2-4 However, the control population studied by Couderc et a1l has an unusually low apo E4 allele frequency (and an unusually high apo E3 frequency of 0.93) that probably reflects subject selection. This is the only group that differs significantly from the other published series of controls. We conclude from these data that the apo E4 allele frequency in ischemic cerebrovascular disease does not differ from that in control populations. We have recently reported a high apo E4 allele frequency in late-onset familial (0.42)3 and sporadic (0.40)5 Alzheimer's disease. The data from the stroke series serve as additional controls, confirming the specificity of the increase of apo E4 allele frequency in late-onset Alzheimer's disease.manian J. Prevalence of apolipoprotein E phenotypes in ischemic cerebrovascular disease: a case-control study. apolipoprotein profile in men with ischemic stroke: role of lipoprotein (a), triglyceride-rich lipoproteins, and apolipoprotein E polymorphism. binding to B-amyloid and increased frequency of type 4 allele in late-onset familial Alzheimer disease.morphism and coronary artery disease. Goldgaber D, Roses AD. Association of apolipoprotein E allele c4 with late-onset familial and sporadic Alzheimer's disease. Neu-rology. In press. Response The association of the apo E alleles with ischemic cerebrovas-cular disease has been effectively reported in two recent articles appearing in Stroke. 1,2 However, Pedro-Botet et a12 …