Characteristics of 46 heterozygous carriers and 57 unaffected relatives in five Danish families with familial defective apolipoprotein B-100.

ABSTRACT

Plasma concentrations of cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) B, and lipoprotein(a) (Lp[a]) in 46 persons heterozygous for the apo B-3500 mutation causing familial defective apo B-100 (FDB) were compared with those in 57 non-FDB relatives. FDB patients had 50% to 70% higher mean concentrations of cholesterol, LDL cholesterol, and apo B than non-FDB relatives (P < 10(-4) for all three variables). Triglycerides were higher (P = .016) and HDL cholesterol was lower (P = .021) in FDB patients. The concentration ranges of these variables were broad in each family, and there was no between-family difference in means for cholesterol and LDL cholesterol. There was no phenotype-specific difference in Lp(a) concentrations between FDB patients and non-FDB relatives. Apo E4 is normally associated with higher concentrations of LDL and apo E2 with lower concentrations. This relation was partly reversed in FDB patients apo E4 was associated with lower apo B concentrations and apo E2 with higher apo B concentrations. Tendon xanthomata were found in members of two of the five families. Six of 12 FDB patients > 50 years old had atherosclerotic disease. In contrast, all 18 non-FDB relatives > 50 years old were apparently healthy. A total of 8 FDB patients with atherosclerotic disease had 36% higher cholesterol concentrations, 28% higher apo B concentrations, 50% higher triglyceride concentrations, and 120% higher Lp(a) concentrations than FDB patients without clinical atherosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)