Apolipoprotein apoB gene

Ladias, J. A., Hadzopoulou-Cladaras, M., Kardassis, D., Cardot, P., Cheng, J., Zannis, V., and Cladaras, C. (1992) Transcriptional regulation of human apolipoprotein genes ApoB, ApoCIII, and ApoAII by members of the steroid hormone receptor superfamily HNF-4, ARP-1, EAR-2, and EAR-3. J. Biol. Chem. 267, 15849-15860. 

The underlying causes are either the absence of a specific enzyme (e.g. lipoprotein lipase in Type I) the absence of a specific apolipoprotein (e.g. apoC2 in another form of Type I) the absence, reduction or impairment of function of specific cell surface receptors (e.g. the LDL receptor in Type Ila) the overproduction of specific apolipoproteins (e.g. apoB in Type Ilb) or the overproduction of lipids in the liver (e.g. triacylglycerols in Types IV and V). Different gene defects may produce the same lipoprotein pattern although by different mechanisms. Alternatively, factors such as body weight and dietary composition may modify the phenotypic expression of a particular genotype. 

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