APOB and hypobetalipoproteinemia: In addition, LOF variants in APOB can cause both hypercholesterolemia or hypobetalipoproteinemia, depending on the type and location of the variant in the gene; missense variants in exon 26 of APOB or nonsense variants in exon 29 lead to hypercholesterolemia, whereas nonsense variants in the first half of APOB cause hypobetalipoproteinemia [42,43].