Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026850 (muscular dystrophy)
 5,870 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several clinical forms of acid alpha-glucosidase deficiency have been described. Our study was planned to identify differences at the molecular level in acid alpha-glucosidase deficiency. Of nine fibroblast strains derived from patients with the infantile form of the disease, eight were crossreacting material (CRM)-negative and one CRM-positive. This was demonstrated by both agar immunodiffusion and immunotitration. No difference in apparent enzymatic activity was observed between CRM-negative and CRM-positive infantile acid alpha-glucosidase deficiency fibroblasts. In two fibroblast strains with the adult form of acid alpha-glucosidase deficiency, rocket immunoelectrophoresis demonstrated a reduction in the amount of enzyme protein, which was directly proportional to the reduction in enzyme activity. In another fibroblast strain obtained from a patient with the adult form of the disease, the activity was within the range of the infantile form and no CRM could be identified. Fibroblasts with phenotype 2 of acid alpha-glucosidase, considered a normal variant, showed a reduction both in the amount of enzyme protein and in the ability of the enzyme to cleave glycogen. However, the catalytic activity for maltose was normal. The findings demonstrate extensive genetic heterogeneity in acid alpha-glucosidase deficiency. Molecular differences were identified both between the clinical forms of the disease and within the infantile and the adult forms of acid alpha-glucosidase deficiency. It remains unknown whether or not the enzyme deficiency in homozygotes for isozyme 2 of acid alpha-glucosidase will be sufficient to cause glycogen accumulation and lead to the development of muscular dystrophy-like disease later in life.
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PMID:Genetic heterogeneity in acid alpha-glucosidase deficiency. 640 21

Adenylosuccinase catalyses two reactions in purine metabolism: the conversion of succinylaminoimidazole carboxamide ribotide (SAICAR) into aminoimidazole carboxamide ribotide (AICAR) along the de novo synthesis of purine nucleotides, and the conversion of adenylosuccinate (S-AMP) into AMP in the conversion of IMP into AMP. The hallmarks of adenylosuccinase deficiency are the presence of succinylaminoimidazole carboxamide riboside (SAICAriboside) and succinyladenosine (S-Ado) in body fluids. These normally undetectable succinylpurines are the products of the dephosphorylation, by cytosolic 5'-nucleotidase, of the two substrates of adenylosuccinase. The clinical picture of the enzyme deficiency is markedly heterogeneous with, as a rule, a profound, but nevertheless variable degree of psychomotor delay, often convulsions and/or autistic features, sometimes growth retardation and muscular dystrophy. The diagnostic tests that can be used for diagnosis, the enzyme and gene defects that have been identified, and the hypotheses that have been put forward to explain the pathophysiology of the disorder are reviewed.
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PMID:Inborn errors of the purine nucleotide cycle: adenylosuccinase deficiency. 921 Nov 92