Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038002 (splenomegaly)
 9,873 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tangier disease is a rare autosomal recessive lipid transport disease characterized by the absence of the usual high density lipoproteins from plasma and cholesteryl ester storage in many organs. 25 cases of Tangier disease have been described so long. The predominant clinical symptoms include tonsilar hypertrophy, splenomegaly and peripheral neuropathy. The cholesteryl ester storage is limited to macrophages, Schwann's cells and intestinal smooth muscle cells. Hypocholest erolemia (less than 80mg/dl), hypertriglyceridemia (greater than 200 mg/dl), and the absence of high density lipoproteins in agarose electrophoresis are the major plasma abnormalities. The protein moiety of normal high density lipoprotein consists of apoprotein A-I and apoprotein A-II. In Tangier disease, serum concentrations of these apoproteins are reduced to less than 1% and 5-10%, respectively. Theories concerning the pathogenesis of Tangier disease are only incomplete and unproved up to now; however, a structural abnormality of apoprotein A-I causing an inability to bind to lipid or other proteins (apoprotein A-II) is consistent with several of the recent biochemical findings. The imbalance of cellular cholesterol metabolism caused by the absence of high density lipoproteins as well as the presumed role of these lipoproteins in cholesterol removal from cells are discussed in this article.
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PMID:[Tangier-disease (author's transl)]. 21 46

We present a six-year follow-up of a boy with a novel type of hypolipoproteinemia, with clinical and biochemical features distinct from classical hypoalphalipoproteinemias. There were abnormally low concentrations of total and high-density lipoprotein (HDL) cholesterol, apolipoprotein (apo) B, apo A-I, and apo A-II, and the phospholipids were decreased. The most striking abnormality was an extra fraction containing mainly phospholipids and apo A-I in the HDL3 subfraction. This fraction is reminiscent of concentric 20- to 50-nm-diameter lamellar phospholipid liposomes. Plasma lecithin:cholesterol acyltransferase activity was strongly decreased. We noted a persisting polyclonal hypergammaglobulinemia, hematological abnormalities (hemolytic anemia and thrombocytopenia), and a progressive splenomegaly. After the five-year follow-up, the patient had recurrent severe infections; moderate hematuria and proteinuria developed gradually. Treatment with corticosteroids and immunoglobulins improved thrombocytopenia and hypolipoproteinemia. These clinical and biochemical findings differ from those in the known primary and secondary hypo-alpha-lipoproteinemia syndromes. Although investigation of the relatives suggests a familial predisposition for hypo-alpha-lipoproteinemia, the subject's condition can be regarded as acquired.
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PMID:Acquired hypolipoproteinemia. 158 35

A new case of C-II anapolipoproteinemia (complete apolipoprotein C-II deficiency) as the cause of severe hypertriglyceridemia with chylomicronemia (type I lipoprotein phenotype) is described. The patient was a five-year-old boy living in Connecticut. He had splenomegaly, episodic abdominal pain, and bloody stools. Absence of apolipoprotein C-II (and its isoforms C-II1 and C-II2) was documented by a sensitive and specific radioimmunoassay, analytical isoelectric focusing, and in vitro lipolytic assay. Decreased levels of high- and low-density lipoprotein cholesterol and apolipoproteins A-I and A-II and increased levels of plasma triglycerides and apolipoprotein E were found. Post-heparin extra-hepatic lipoprotein lipase activity was within normal range. Incorporation of exogenous purified human apolipoprotein C-II to an incubation mixture of purified lipoprotein lipase and the patient's triglyceride-rich lipoproteins resulted in a dramatic increase in the catabolic rate of the defective triglyceride-rich lipoproteins. The absence of the isoforms of apolipoprotein C-II in this patient indicates that a common gene exists for the C-II isoproteins, which appear to be necessary for normal triglyceride transport in humans. A literature review of 23 reported cases indicates that xanthomas and hepatosplenomegaly are less common in C-II anapolipoproteinemia than in lipoprotein lipase deficiency, the other major etiologic cause of genetic chylomicronemia.
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PMID:C-II anapolipoproteinemia and severe hypertriglyceridemia. Report of a rare case with absence of C-II apolipoprotein isoforms and review of the literature. 647 85

A 48-yr-old Caucasian female of central European origin (subject IM) with low plasma cholesterol and normal plasma triglyceride (TG) had extremely low apo A-I (6 mg/dl), A-II (5 mg/dl), and HDL cholesterol (2 mg/dl) levels. She had most of the clinical symptoms typically associated with Tangier disease, including early corneal opacities, yellow-streaked tonsils, hepatomegaly, and variable degrees of peripheral neuropathy, but had no splenomegaly. She had a myocardial infarction at age 46. Since HDL are postulated to be involved in the transport of excess cholesterol from peripheral tissues to the liver for degradation, and the ability of an HDL particle to promote cellular cholesterol efflux appears to be related to its density, size, and apo A-I and A-II contents, we isolated and characterized the HDL particles of this patient and all her first degree relatives (mother, a brother, and two children). The plasma A-I, A-II, and HDL cholesterol levels of all five relatives were either normal or high. Using anti-A-I and anti-A-II immunosorbents, we found three populations of particles in IM: one contained both apo A-I and A-II, Lp(AI w AII); one contained apo A-I but no A-II, Lp(AI w/o AII); and the third (an unusual one) contained apo A-II but no A-I, Lp(AII). Two-thirds of her plasma A-I and A-II existed in separate HDL particles, i.e., in Lp(AI w/o AII) and Lp(AII), respectively. Only Lp(AI w AII) and Lp(AI w/o AII) were present in the plasma of the relatives. All three populations of the patient's HDL particles had a normal core/surface lipid ratio, but the cores were enriched with TG. The apo A-I-containing particles, however, were considerably smaller and contained much less lipid than Lp(AII). Despite these unusual physicochemical characteristics, the apo A-I-containing particles and Lp(AII) were effective suppressors of intracellular cholesterol esterification in cholesterol-loaded human skin fibroblast. The patient's plasma apo D and lecithin cholesterol acyltransferase levels were reduced, with an increased proportion located in non-HDL plasma fractions. These findings are discussed in light of Tangier disease and other known HDL-deficiency cases, and the role of HDL in the maintenance of cell cholesterol homeostasis.
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PMID:Characterization of apolipoprotein A-I- and A-II-containing lipoproteins in a new case of high density lipoprotein deficiency resembling Tangier disease and their effects on intracellular cholesterol efflux. 843 61