[Progress in the diagnosis of endocrine and metabolic disorders: hyperlipidemia]

Hyperlipidemia is one of the risk factors for coronary atherosclerosis and the establishment of its simple etiological diagnosis is crucial. Hyperlipidemia can be classified into primary and secondary hyperlipidemia. Primary hyperlipidemia includes familial lipoprotein lipase (LPL) deficiency, familial hypercholesterolemia (FH), familial type III hyperlipidemia, and familial combined hyperlipidemia. Many genetic mutations have been identified in patients with familial LPL deficiency and FH. An ELISA kit has been established to determine LPL mass levels, using monoclonal antibodies against LPL. FH is a deficiency of LDL receptor and is characterized by marked hypercholesterolemia and Achilles tendon xanthomas. It can be diagnosed by an LDL receptor assay, using 125I-LDL in skin fibroblasts. However, the diagnosis can be made easily by measuring the uptake of DiI-LDL by peripheral lymphocytes. Familial type III hyperlipidemia is a genetic disorder characterized by the presence of a broad beta pattern in lipoprotein electrophoresis and is based upon the abnormality of apo E isoform (apo E2/2). Apo E4 has been shown to be associated with late-onset Alzheimer's disease. Cholesteryl ester transfer protein (CETP) deficiency is characterized by a marked hyperalphalipoproteinemia and various abnormalities in the size and composition of LDL and HDL. Two common mutations in the CETP deficiency have been identified; an intron 14 splicing defect and D442: G missense mutation. These mutations account for at least one half of hyper-HDL-cholesterolemia in the Japanese. We have recently identified an area (Omagari City, Akita) where the frequency of heterozygotes for the intron 14 splicing defect is approximately 28% of the general population.(ABSTRACT TRUNCATED AT 250 WORDS)