A deletion polymorphism of alpha(2)-macroglobulin gene and cerebral amyloid angiopathy.

BACKGROUND AND PURPOSE: alpha(2)-Macroglobulin may be implicated in amyloid beta protein deposition. A deletion in the exon 18 splice acceptor of the alpha(2)-macroglobulin gene (A2M) has been reported to be associated with risk for Alzheimer's disease (AD). In search of genetic risk factors for cerebral amyloid angiopathy (CAA), we investigated association of the A2M deletion polymorphism with CAA. METHODS: The association between the severity of CAA and A2M deletion polymorphism was investigated in 178 autopsy cases of the elderly including 68 patients with AD. RESULTS: There was no significant difference in the severity of CAA between individuals with the A2M deletion allele and those without in the AD, non-AD, or total cases. Status for the epsilon4 allele of the apolipoprotein E gene did not influence the results. CONCLUSIONS: Our results suggest that the A2M deletion polymorphism may not be a definitive risk factor of CAA in the elderly, although further study with larger samples is necessary to confirm this.