Dysbetalipoproteinemia and other lipid abnormalities related to apo E

Dysbetalipoproteinaemia (or type III hyperlipoproteinaemia) is a severe mixed hyperlipidaemia resulting from the accumulation of remnant chylomicron and VLDL particles in plasma, also called β-VLDL. It is caused by a defect in the recognition by hepatic LDL and lipoprotein receptor-related protein (LRP) of β-VLDL. Mutations in the APOE gene, especially in subjects homozygous for the ɛ2/ɛ2 allele, are responsible for this lack of receptor recognition. Dysbetalipoproteinaemia represents 2-5% of the mixed dyslipidaemias seen in Lipid Units, is highly atherogenic and predisposes to diffuse atheromatosis, either coronary, peripheral vascular, or carotid, so early diagnosis and treatment is necessary. The presence of hypertriglyceridaemia, with non-HDL cholesterol/apolipoprotein B ratios>1.43 (in mg/dL) followed by APOE genotyping is the method of choice in the diagnosis of dysbetalipoproteinaemia. It is a dyslipidaemia that responds well to hygienic-dietary treatment, although the combination of statin and fenofibrate is often necessary to achieve optimal control.