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)

Lysinuric protein intolerance (LPI), an autosomal recessive defect of diamino acid transport, is characterized chemically by renal hyperdiaminoaciduria, especially lysinuria, and by impaired formation of urea with hyperammonemia after protein ingestion. Our 20 patients thrived during breast-feeding, but ingestion of cow's milk caused diarrhea and vomiting. When able to select their diet, they rejected all protein-rich foods. They were short staturated and had weak atrophic muscles, osteoporosis, hepatomegaly and often splenomegaly. Four patients were mentally retarded. Fifteen patients had leukocyte counts below 4,000/mm3, and 17 patients had platelet counts below 150,000/mm3. Serum lactate dehydrogenase activity was constantly increased, and transaminase and aldolase activities were often increased. In the infants' livers, changes were only revealed by electron microscopy: increased and vesicular smooth endoplasmic reticulum, and abundance of glycogen particles in the hepatocytes. In the older patients, light microscopy demonstrated clearly limited areas where hepatocytes had large pale cytoplasm and small pyknotic nuclei. The diamino acids lysine, arginine and ornithine had plasma concentrations only one-third to one-half the normal mean; the renal clearances were clearly increased. Oral diamino acid loading tests suggested impaired intestinal absorption. Urea is built in the liver through transformation of ornithine to arginine, and cleavage of arginine to ornithine and urea. The addition of ornithine to an intravenous I-alanine loading prevented the hyperammonemia and normalized the urea production. Therefore, the diet has been supplemented with arginine, and more protein has been added. This therapy has lead to a remarkable catch-up growth in some patients. The pathophysiology of LPI is explained. Because of defective intestinal absorption and incrased renal loss, the diamino acids have a low plasma concentration. Their transport from plasma to hepatocytes is also impaired, and the liver becomes deficient in ornithine. This retards the urea cycle, and leads to postprandial hyperammonemia and protein aversion. The presence of the transport defect in the hepatocytes distinguishes LPI from other hyperdibasicaminoacidurias.
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PMID:Lysinuric protein intolerance. 115 80

In lysinuric protein intolerance, a disease resulting from an autosomal recessive disorder of diamino acid transport, citrulline, unlike arginine and lysine, is absorbed normally from the intestine. In 19 patients with LPI, the status after 2 years of treatment with citrulline or citrulline + lysine was compared with that during the preceding period of treatment with arginine. Administration of citrulline led to improved protein nutrition, as indicated by increases in daily protein intake, blood hemoglobin values, and plasma albumin and valine concentrations. Normal excretion of orotic acid indicated adequate urea cycle function. Seven of the nine stunted children had marked catch-up growth. Of four patients biopsied twice and having initially severe fatty degeneration of the liver, two had improved histology. However, hepato- and splenomegaly, and several biochemical abnormalities in the serum remained unchanged. Giving additional lysine did not enhance the favorable effect, but in some patients provoked abdominal cramps and diarrhea. Citrulline is the most valuable agent for treatment of LPI. Although not curative, it corrects the deficiency of the urea cycle intermediates and protects the patients from hyperammonemia and its consequences.
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PMID:Lysinuric protein intolerance: a two-year trial of dietary supplementation therapy with citrulline and lysine. 677 79