POLYMORPHISMS IN THE HUMAN APOLIPOPROTEIN-J CLUSTERIN GENE - ETHNIC VARIATION AND DISTRIBUTION IN ALZHEIMERS-DISEASE/

Apolipoprotein-J/clusterin (APOJ/CLI) shares many biological propertie s with apolipoprotein-E (APOE) including, but not limited to, avid bin ding with P-amyloid peptide. Thus, APOJ/CLI warrants scrutiny as a can didate Alzheimer's disease (AD) susceptibility gene. We identified sev en nucleotide sequence polymorphisms in APOJ/ CLI, two of which, in ex on 7, alter the predicted amino acid sequence. The JVIIB variant is an asparagine-to-histidine substitution, which deletes a glycosylation s ignal at amino acid 317; the JVIIC variant is an aspartate-to-asparagi ne substitution, which forms a new glycosylation signal at position 32 8. Both of these coding variants, as well as two neutral polymorphisms in exon 2, were more frequent in African-Americans than Hispanics and were rare in Caucasians. However; no individual coding or non-coding variant was consistently associated with AD. At the population level, APOJ/CLI polymorphisms are frequent among persons of African descent, but probably do not alter susceptibility to AD.