Normal Vascular Function Despite Low Levels of High-Density Lipoprotein Cholesterol in Carriers of the Apolipoprotein A-I Milano Mutant

Carriers of the apolipoprotein A-I(Milano) (apoA-I(M)) mutant have very low plasma high-density lipoprotein cholesterol (HDL-C) levels but do not show any history of premature cardiovascular disease or any evidence of preclinical vascular disease. HDL is believed to prevent the development of vascular dysfunction, which may well contribute to HDL-mediated atheroprotection. Whether the low HDL level of apoA-I(M) carriers is associated with impaired vascular function is presently unknown.