Genetic predisposition to hyperlipidaemia in diabetes: the end of the beginning?

Diabetes mellitus leads to disturbances in lipoprotein homeostasis particularly when there is poor glycaemic control. The resulting abnormalities in concentration and composition of the circulating lipoproteins are modified by inherited variation in the genes coding for apolipoproteins, for the lipoprotein-processing enzymes, and possibly for lipoprotein receptors. Thus, poorly controlled diabetes provides an opportunity to observe the phenotypic effects of recessive mutant alleles that would otherwise be silent. This phenomenon should be considered when one attempts to understand the pathogenesis of variant phenotypes, ones differing from those typical of diabetes mellitus alone. Our understanding of how genetic variation modulates the expression of hyperlipidaemia in diabetes is still rudimentary--it now seems probable that many other genetic conditions affecting lipoprotein metabolism in diabetes will eventually be brought to light.