Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018099 (gout)
 5,192 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

AMP deaminase activity was undetectable by a sensitive spectrophotometric assay in the muscle biopsy of a 37-year-old man with gout and exercise-related cramps and myalgia. Venous ammonia failed to rise after ischemic exercise, but the diagnostic value of this test is uncertain because changes of plasma ammonia after exercise varied greatly in different normal individuals. In the patient, AMP deaminase activity was normal not only in erythrocytes, leukocytes and cultured fibroblasts but also in muscle cultures. Presence of AMP deaminase in muscle cultures was probably due to the expression of a fetal isoenzyme under separate genetic control from adult muscle AMP deaminase.
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PMID:Myoadenylate deaminase deficiency--muscle biopsy and muscle culture in a patient with gout. 741 Nov 67

In man, there are at least four isoforms of adenosine monophosphate deaminase (AMPD): myoadenylate deaminase in skeletal muscle, the L isoform in liver, and the E1 and E2 isoforms in erythrocytes. Myoadenylate deaminase is encoded by the AMPD1 gene located on chromosome 1 p13-p21, the L isoform by the AMPD2 gene, and both isoforms in erythrocytes by the AMPD3 gene. Myoadenylate deaminase deficiency is found in 2-3% of all muscle biopsies. The inborn type of myoadenylate deaminase deficiency is caused by a single mutant allele harbouring two mutations: C34-->T (Gln-->Stop) and C143-->T (Pro-48-->Leu). Population studies revealed a frequency of the mutant allele of 0.12 in Caucasian Americans and Germans. The C34-->T mutation is located in exon 2, which is alternatively spliced in part of the AMPD1 transcript in human muscle. Since the second mutation does not affect enzyme function, alternatively spliced mRNA encodes a catalytically active enzyme. Only one patient with a disorder linked to liver AMPD has been described so far. In this patient the decreased inhibition of this enzyme by GTP resulted in uric acid overproduction and gout. A complete lack of erythroyte AMPD activity is found in asymptomatic subjects. The molecular basis of both disorders is not yet known.
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PMID:Molecular biology of AMP deaminase deficiency. 803 42