Turnover of apolipoprotein-B in two subjects with familial hypobetalipoproteinemia.

The metabolism of the apoprotein of low-density apoliporprotein-B was studied in a father and son with familial hypobetalipoproteinemia. The synthetic rate of apolipoprotein-B was below the normal range in both subjects, while the fractional removal rate was normal. It is concluded that the subnormal concentration of low-density lipoprotein (LDL) inthese two subjects is due to a low synthetic rate. The synthetic rate of apolipoprotein-B of very low-density lipoprotein (BLDL-apoB) measured in the father was subnormal. The fraction of the VLDL-apoB pool which was oncverted into LDL-apoB was within the normal range. It is suggested that a low synthetic rate of VLDL may underlie the disorder.