From OMIMHypobetalipoproteinemia (HBL) is defined as permanently low levels, below the 5th percentile of sex- and age-matched individuals in the population, of apolipoprotein B (apoB), total cholesterol, and low-density lipoprotein (LDL) cholesterol; the lipid profile in FHBL2 includes low HDL cholesterol as well. HBL can result from environmental factors such as a strict vegetarian diet, or can be secondary to certain diseases such as intestinal fat malabsorption, chronic pancreatitis, severe liver disease, malnutrition, or hyperthyroidism. Heritable primary causes of HBL include chylomicron retention disease (CMRD; 246700), abetalipoproteinemia (200100), and familial hypobetalipoproteinemia (FHBL) (summary by Martin-Campos et al., 2012).
For a discussion of genetic heterogeneity of familial hypobetalipoproteinemia, see FHBL1 (615558).
http://www.omim.org/entry/605019 From MedlinePlus GeneticsFamilial hypobetalipoproteinemia (FHBL) is a disorder that impairs the body's ability to absorb and transport fats. This condition is characterized by low levels of a fat-like substance called cholesterol in the blood. The severity of signs and symptoms experienced by people with FHBL vary widely. The most mildly affected individuals have few problems with absorbing fats from the diet and no related signs and symptoms. Many individuals with FHBL develop an abnormal buildup of fats in the liver called hepatic steatosis or fatty liver. In more severely affected individuals, fatty liver may progress to chronic liver disease (cirrhosis). Individuals with severe FHBL have greater difficulty absorbing fats as well as fat-soluble vitamins such as vitamin E and vitamin A. This difficulty in fat absorption leads to excess fat in the feces (steatorrhea). In childhood, these digestive problems can result in an inability to grow or gain weight at the expected rate (failure to thrive).
https://medlineplus.gov/genetics/condition/familial-hypobetalipoproteinemia