abetalipoproteinemia (MONDO_0008692)/ homozygous familial hypobetalipoproteinemia (ABL/HoFHBL) is a severe form of familial hypobetalipoproteinemia characterized by permanently low levels (below the 5th percentile) of apolipoprotein B and LDL cholesterol, and by growth delay, malabsorption, hepatomegaly, and neurological and neuromuscular manifestations. Also known as: Bassen-Kornzweig disease, familial hypobetalipoproteinemia, homozygous familial hypobetalipoproteinemia, microsomal triglyceride transfer protein deficiency disease.