Studies on a beta-migrating high density lipoprotein.

An unusual serum lipoprotein (Lp) profile was detected in a Japanese family. A double beta-Lp was observed when serum was subjected to polyacrylamide gel electrophoresis. The slower migrating beta-Lp was identified as a subfraction of high density lipoprotein (HDL). It was present in the d 1.063--1.21 fraction, migrated to the position designated as the midband L.1 (sinking pre-beta-lipoprotein) by Mead, M.G. and Dangerfield, W.G. (1974) (Clin. Chim. Acta 51, 173--182) [1], and reacted against human anti-beta-Lp antiserum. This lipoprotein contained greater amounts of triglyceride than the usual beta-lipoprotein and could not be clearly detected by paper electrophoresis. Individuals exhibiting this high density midband lipoprotein appeared to be heterozygous for an autosomal dominant gene. Although other reports have indicated the possibility of a positive association between the occurrence of serum lipoproteins with unusual eletrophoretic mobility and premature ischemic heart disease, no such correlation was demonstrable in these subjects.