0000000000462753
AUTHOR
Jürgen Geisel
Detection of mutations in the apolipoprotein CII gene by denaturing gradient gel electrophoresis. Identification of the splice site variant apolipoprotein CII-Hamburg in a patient with severe hypertriglyceridemia
AbstractFamilial apolipoprotein (apo) CII deficiency is a rare autosomal recessive inborn error of metabolism clinically resembling lipoprotein lipase deficiency. A number of mutations of the apo CII gene are known to date; they are located in the promoter region, the coding exons, or in the splice junctions. We present a simple assay based on PCR and denaturing gradient gel electrophoresis, which allows scanning of the promoter, the entire coding sequence, and the splice junctions of the apo CII gene for sequence variants. All gene fragments are amplified using a common PCR protocol and are examined for mutations on a single gradient gel. Using this method and direct sequencing, we identif…
Lipid-free apolipoprotein (apo) A-I is converted into alpha-migrating high density lipoproteins by lipoprotein-depleted plasma of normolipidemic donors and apo A-I-deficient patients but not of Tangier disease patients
Plasma of patients with Tangier disease (TD) is devoid of alpha-LpA-I (apolipoprotein A-I-containing lipoprotein), which in normolipidemic plasma constitutes the majority of high density lipoprotein (HDL). The residual amounts of apolipoprotein A-I (apo A-I) in TD plasma have electrophoretic prebeta1-LpA-I mobility. We have previously demonstrated that TD plasma does not convert prebeta1-LpA-I into alpha-LpA-I. In this study we found that plasmas of normolipidemic controls, apo A-I-deficient patients and patients with fish-eye disease, but not plasmas of six TD patients, convert biotinylated lipid-free apo A-I into alpha-LpA-I. Supplementation of plasma with free oleic acid or fatty acid fr…
Plasma and fibroblasts of Tangier disease patients are disturbed in transferring phospholipids onto apolipoprotein A-I
Plasmas of patients with Tangier disease (TD) lack lipid-rich α-HDL which, in normal plasma, constitutes the majority of high density lipoprotein (HDL). Residual amounts of apolipoprotein (apo)A-I in TD plasma occur as lipid-poor or even lipid-free preβ-HDL. By contrast to normal plasma, TD plasma does not convert preβ-HDL into α-HDL. Moreover, fibroblasts of TD patients were found to be defective in secreting cholesterol or phospholipids in the presence of lipid-free apoA-I. We have therefore hypothesized that both defective conversion of preβ-HDL into α-HDL and defective lipid efflux from TD cells onto lipid-free apoA-I result from a disturbance in phospholipid transfer occurring in both …