High-density lipoprotein composition is altered by a common DNA polymorphism adjacent to apoprotein AII gene in man.

25 of a group of 87 White men had Msp 1 restriction site polymorphism within an Alu sequence 3' to the human apo AII gene. Homozygosity for the polymorphism in 8 men was associated with a significant increase in serum apo AII levels (35.4 +/- 1.70 mg/dl, mean +/- SEM) and altered HDL composition, compared with heterozygotes (31.7 +/- 1.29; n = 17) and normal subjects (29.4 +/- 0.64; n = 62). This is the first account of a common variant of an HDL apoprotein gene that affects HDL composition. In view of its association with a high apo AII concentration homozygosity may protect against atherosclerosis.