Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019209 (hepatomegaly)
 5,798 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The lysosomal enzyme responsible for cholesteryl ester hydrolysis, acid cholesteryl ester hydrolase, or acid lipase (E.C.3.1.1.13) plays an important role in cellular cholesterol metabolism. Loss of the activity of this enzyme in tissues of individuals with both Wolman disease and cholesteryl ester storage disease is believed to play a causal role in these conditions. The objectives of our studies were not only to directly compare and contrast the clinical features of Wolman disease and cholesteryl ester storage disease but also to determine the reasons(s) for the varied phenotype expression of acid cholesteryl ester hydrolase deficiency. Although both diseases manifest a type II hyperlipoproteinemic phenotype and hepatomegaly secondary to lipid accumulation, a more malignant clinical course with more significant hepatic and adrenal manifestations was observed in the patient with Wolman disease. However, the acid cholesteryl ester hydrolase activity in cultured fibroblasts in both diseases was virtually absent. In addition, fibroblasts from both Wolman disease and cholesteryl ester storage disease were able to utilize exogenously supplied enzyme, suggesting that neither disease was due to defective enzyme delivery by the mannose-6-phosphate receptor pathway. Coculture and cell fusion of fibroblasts from Wolman disease and cholesteryl ester storage disease subjects did not lead to correction of the enzyme deficiency, indicating that these disorders are allelic. However, the activities of the hepatic acid and neutral lipase in these two clinical variants were quite different. Hepatic acid lipase activity was only 4% normal in Wolman disease, but the activity was 23% normal in cholesteryl ester storage disease. The hepatic neutral lipase activity was normal in Wolman disease but increased more than twofold in cholesteryl ester storage disease. These combined results indicate that the clinical heterogeneity in acid cholesteryl ester hydrolase deficiency can be explained by a varied hepatic metabolic response to an allelic mutation.
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PMID:Cholesteryl ester storage disease and Wolman disease: phenotypic variants of lysosomal acid cholesteryl ester hydrolase deficiency. 609 11

Cholesteryl ester storage disease (CESD, OMIM #278000) and Wolman disease (OMIM #278000) are autosomal recessive lysosomal storage disorders caused by a deficient activity of lysosomal acid lipase (cholesteryl ester hydrolase, LAL). Human lysosomal acid lipase is essential for the metabolism of cholesteryl esters and triglycerides. In Wolman disease, LAL activity is usually absent, whereas CESD usually presents some residual LAL activity. In infants, poor weight gain, massive hepatosplenomegaly, calcified adrenal glands (present about 2/3 of the time), vomiting, diarrhea and failure to thrive are indicative of Wolman disease. The clinical picture is more variable in CESD. Hepatomegaly and/or elevation of liver transaminases are almost always present. Hepatic steatosis often leads to fibrosis and cirrhosis. Other signs often include splenomegaly, high total cholesterol and LDL-cholesterol, elevated triglycerides, and low HDL-cholesterol. The diagnosis of LAL deficiency requires clinical experience and specialized laboratory tests. The diagnosis is based on finding deficient activity of acid lipase and/or molecular tests. Pilot screening projects using dried blood spot testing in 1) children with atypical fatty liver disease in the absence of overweight, 2) patients with dyslipidaemia and presence of hepatomegaly and/or elevated transaminases, 3) newborns/neonates with hepatomegaly and abdominal distension/failure to thrive/elevated transaminases are currently underway. Early diagnosis is particularly important for the enzyme replacement therapy. Human trials with recombinant LAL are currently ongoing, raising the prospect for specific correction of LAL deficiency in this progressive and often debilitating disorder.
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PMID:Lysosomal acid lipase deficiency: wolman disease and cholesteryl ester storage disease. 2479