Hypobetalipoproteinemia Explained

Hypobetalipoproteinemia is a disorder consisting of low levels of LDL cholesterol or apolipoprotein B,^[1] below the 5th percentile.^[2] The patient can have hypobetalipoproteinemia and simultaneously have high levels of HDL cholesterol.

Notably, in people who do not have the genetic disorder hypobetalipoproteinemia, a very low cholesterol level (less than 100 mg/dl) may be a marker for poor nutrition, wasting disease, cancer, hyperthyroidism, and liver disease. In 1997 a study showed that Japanese Centenarians had tenfold increase of hypobetalipoproteinemia compared with controls.

Causes

One form is thought to be caused by mutated apolipoprotein B.^[3]

Another form is associated with microsomal triglyceride transfer protein which causes abetalipoproteinemia.

A third form, chylomicron retention disease (CRD), is associated with SARA2.^[4]

Diagnosis

Typically in hypobetalipoproteinemia, plasma cholesterol levels will be around 80–120 mg/dL, LDL cholesterol will be around 50–80 mg/dL.

Treatment

Early high doses of vitamin E in infants and children has shown to be effective.^[5]

Notes and References

1. Schonfeld G, Lin X, Yue P . Familial hypobetalipoproteinemia: genetics and metabolism . Cell. Mol. Life Sci. . 62 . 12 . 1372–8 . June 2005 . 15818469 . 10.1007/s00018-005-4473-0. 9054743 . 11139194 .
2. Schonfeld G . Familial hypobetalipoproteinemia: a review . J. Lipid Res. . 44 . 5 . 878–83 . May 2003 . 12639976 . 10.1194/jlr.R300002-JLR200 . free .
3. Young SG . Familial hypobetalipoproteinemia associated with a mutant species of apolipoprotein B (B-46) . . 320 . 24 . 1604–10 . June 1989 . 2725600 . 10.1056/NEJM198906153202407. vanc. Hubl ST . Chappell DA . 3 . Smith . Richard S. . Claiborne . Frederica . Snyder . Steven M. . Terdiman . Joseph F..
4. Tarugi P . Molecular diagnosis of hypobetalipoproteinemia: an ENID review . Atherosclerosis . 195 . 2 . e19–27 . December 2007 . 17570373 . 10.1016/j.atherosclerosis.2007.05.003 . vanc. Averna M . Di Leo E . 3 . Cefalu . A . Noto . D . Magnolo . L . Cattin . L . Bertolini . S . Calandra . S.
5. Zamel . Rola . Khan . Razi . Pollex . Rebecca L. . Hegele . Robert A. . 2008-07-08 . Abetalipoproteinemia: two case reports and literature review . Orphanet Journal of Rare Diseases . 3 . 19 . 10.1186/1750-1172-3-19 . 18611256 . 1750-1172. 2467409 . free .