Other APOB mutations cause abetalipoproteinemia (ABL) (OMIM, 200100) and hypobetalipoproteinemia (FHBL) (OMIM, 615558), two rare, autosomal recessive disorders characterized by hypocholesterolemia and malabsorption of fat-soluble vitamins, causing neuropathy, coagulopathy, and retinal degeneration [14]. Here, APOB is linked to abetalipoproteinemia.