Familial Hypobetalipoproteinemia (FHBL) |
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Abetalipoproteinemia is a genetic condition that affects several organ systems of the body. These affects are caused by the body’s inability to absorb the lipids (fats) ingested from the diet as well as the fat soluble vitamins (A, D, E and K). Appropriate levels of these vitamins, especially vitamin E are crucial for normal growth and development. Familial Hypobetalipoproteinemia (FHBL) is a genetic condition which causes decreased production of apolipoprotein B. Apolipoprotein B has two forms, apoB-48 and apoB-100. Apolipoprotein B is the main apolipoprotein in chylomicrons and LDL. (see Apolipoproteins and Lipoproteins) The majority of cases of Familial Hypobetalipoproteinemia (FHBL) are caused by a mutation in the APOB gene located on chromosome 2. There are some families that also have this condition because of a mutation in a gene on chromosome 3 (FHBL2). In addition, there are some families that have FHBL that do not have mutation in either of these genes. Therefore, there must be other genes that can also cause FHBL that have not yet been found. Ideogram of chrom 2 (q24) Sources: |
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