Heterogeneity of lipoprotein electrophoretic patterns in patients with type IIa hyperlipoproteinemia.

Previous evaluations of plasma lipoproteins from patients with type IIa hyperlipoproteinemia have demonstrated quantitative but not qualitative differences from lipoproteins isolated from normal subjects. Using a reproducible, sensitive, high-resolution agarose gel electrophoretic system, we evaluated the plasma lipoprotein of 22 consecutive, untreated, unrelated patients with type IIa hyperlipoproteinemia. Five distinct electrophoretic patterns were observed. This electrophoretic heterogeneity in type IIa hyperlipoproteinemia reflects subtle charge differences in the lipoproteins from these patients, which were not detected with paper electrophoresis or with lipoprotein quantification. There was little, if any, difference in total plasma cholesterol, low- or very-low-density lipoproteins, plasma triglycerides, or concentrations of apolipoproteins A-I, A-II, B, C-II, or E in these subgroups. However, unique clinical features were correlated with the electrophoretic patterns. These findings support the concept that the type IIa hyperlipoproteinemic phenotype includes several molecular defects that are reflected in subtle differences in lipoprotein charge.