Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042875 (vitamin E deficiency)
 916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Liver disease, particularly alcoholic cirrhosis, is associated with a number of interesting chemical changes which result in structural and metabolic abnormalities of the erythrocyte membrane leading to microscopically observable cell shape changes and hemolytic anemia varying from very mild to potentially lethal. Increase in unesterified serum cholesterol owing to lecithin cholesterol acyl transferase (LCAT) deficiency in cirrhosis leads to expansion of the lipid bilayer and macrocytosis without megaloblastic changes in precursors. Substitutions of phosphatidyl choline (PC) moieties in the erythrocyte lipid bilayer lead to echinocytes (disaturated PC) or to stomatocytes (diunsaturated PC). In some patients, high density lipoprotein (HDL) abnormalities lead to erythrocyte surface changes causing rapid formation of echinocytes. The rapidity and reversibility of these changes suggest blockade of metabolic transport channels critical to the maintenance of erythrocyte membrane shape. Metabolic changes involving vitamin E deficiency leading to lipid peroxidation and pyruvate kinase instability leading to adenosine triphosphate (ATP) reduction have also been invoked to explain hemolysis associated with acute liver damage. The most severe hemolysis in liver disease is associated with acanthocytes (spur cells) and a marked imbalance in cholesterol-phospholipid ratio. These patients usually have hypersplenism, as well as rigid erythrocyte membrane transformations which are irreversible. Any of the other erythrocyte membrane shape changes described appear to be reversible if the liver disease abates, but they too may become irreversible if bits of projecting membrane are repeatedly removed by the macrophages of an enlarged spleen.
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PMID:Mechanisms of hemolysis in liver disease. 218 63

The catalytic properties of many enzymes depend on the participation of vitamins as obligatory cofactors. Vitamin B12 (cobalamin) and folic acid (folate) deficiencies in infants and children classically present with megaloblastic anemia and are often accompanied by neurological signs. A number of rare inborn errors of cobalamin and folate absorption, transport, cellular uptake, and intracellular metabolism have been delineated and identification of disease-causing mutations has improved our ability to diagnose and treat many of these conditions. Two inherited defects in biotin metabolism are known, holocarboxylase synthetase and biotinidase deficiency. Both lead to multiple carboxylase deficiency manifesting with metabolic acidosis, neurological abnormalities, and skin rash. Thiamine-responsive megaloblastic anemia is characterized by megaloblastic anemia, non-type I diabetes, and sensorineural deafness that responds to pharmacological doses of thiamine (vitamin B1). Individuals affected with inherited vitamin E deficiencies including ataxia with isolated vitamin E deficiency and abetalipoproteinemia present with a spinocerebellar syndrome similar to patients with Friedreich's ataxia. If started early, treatment of these defects by oral or parenteral administration of the relevant vitamin often results in correction of the metabolic defect and reversal of the signs of disease, stressing the importance of early and correct diagnosis in these treatable conditions.
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PMID:Vitamin-responsive disorders: cobalamin, folate, biotin, vitamins B1 and E. 2362 2