Our results are in line with an earlier published apoB kinetic study in a family with familial hypobetalipoproteinemia,16 which was later reclassified as familial combined hypolipidemia caused by ANGPTL3 LOF variants.1 The affected family members presented with lower VLDL apoB production rates, and increased IDL and LDL apoB FCRs compared with unaffected family controls,16 with a clear gene dose effect.1 This evidence concerns the gene APOB and hypobetalipoproteinemia.