Familial Apolipoprotein Al

A bstract. Lipoprotein classes isolated from the plasma of two patients with apolipoprotein Al (apo Al) and apolipoprotein CIII (apo CIII) deficiency were characterized and compared with those of healthy, ageand sex-matched controls. The plasma triglyceride values for patients 1 and 2 were 31 and 51 mg/dl, respectively, and their cholesterol values were 130 and 122 mg/dl, respectively; the patients, however, had no measurable high density lipoprotein (HDL)-cholesterol. Analytic ultracentrifugation showed that patients' S° 0-20 lipoproteins possess a single peak with S° rates of 7.4 and 7.6 for patients 1 and 2, respectively, which is similar to that of the controls. The concentration of low density lipoprotein (LDL) (S' 0-12) particles, although within normal range (331 and 343 mg/dl for patients 1 and 2, respectively), was 35% greater than that of controls. Intermediate density lipoproteins (IDL) and very low density lipoproteins (VLDL) (S° 20-400) were extremely low in the patients. HDL in the patients had a calculated mass of 15.4 and 11.8 mg/dl for patients 1 and 2, respectively. No HDL could be detected by analytic ultracentrifugation, but polyacrylamide gradient gel electrophoresis (gge) revealed that patients possessed two major HDL subclasses: (HDL2b)gge at 11.0 nm and (HDL3b)gge at 7.8 nm. The major peak in the controls, (HDL3a)gge, was lacking in the patients. Gradient gel analysis of LDL indicated that patients' LDL possessed two peaks: a major one at 27 nm and a minor one at 26 nm. The electron microscopic structure of patients'