Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Muscle biopsies from three patients with cardiomyopathy, mental retardation and increased serum creatine kinase levels revealed scattered fibers with tiny intracytoplasmic vacuoles containing basophilic and acid phosphatase-positive material and slightly increased amounts of PAS-positive granules. These findings are consistent with those seen in the so-called lysosomal glycogen storage disease with normal acid maltase. In addition to the vacuoles, there were occasional folds or indentations in the sarcolemma which were connected to the membrane enclosing the vacuoles. These membranes were well demonstrated histochemically by the nonspecific esterase and acetylcholinesterase stains. On electron microscopy, most of the vacuoles were bounded by membranes with basal lamina. The vacuolar membrane stained positively with antibodies raised to dystrophin, dystrophin-associated glycoproteins, laminin and type 4 collagen, and it was identical to the sarcolemma and its basal lamina. Therefore, the membrane abnormality which causes sarcolemmal folding is probably critical to understanding the pathomechanism of this disease.
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PMID:Sarcolemmal indentation in cardiomyopathy with mental retardation and vacuolar myopathy. 753 16

Glycogen storage disease with normal acid maltase first reported by Danon et al. was characterized clinically by mental retardation, cardiomyopathy, and proximal myopathy. Since the first report, 17 patients have been reported including 5 patients from Japan. In this paper we described a 26-year-old man who had dilatated cardiomyopathy with a pacemaker implanted at age 22 years. He was admitted to our hospital complaining of easy fatigability in February 1992. Neurological findings showed that he had mental retardation. Serum CK, GOT, GPT and aldolase levels were elevated. Histopathological study of biopsied skeletal muscle showed intracytoplasmic vacuoles with increased acid phosphatase and slightly increased PAS positive material. Electron microscopic study revealed numerous glycogenosomes (autophagic vacuoles containing glycogen). These pathological findings were similar to acid maltase deficiency, but activities of carbohydrate metabolic enzyme including acid maltase activity were normal in the biopsied muscle. From these results, he was diagnosed as having glycogen storage disease with normal acid maltase. We also found abnormal platelet function and glycogen accumulation in the platelets, which have not been previously described. The disease is probably a systemic disorder affecting not only skeletal and cardiac muscles, but platelets.
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PMID:[A case of glycogen storage disease with normal acid maltase accompanied with the abnormal platelet function]. 799 92

A 13-year-old boy with mental retardation developed idiopathic cardiomyopathy and glycogen storage myopathy, but with normal lysosomal enzyme activities, consistent with a syndrome of lysosomal glycogen storage disease with normal acid maltase coined by Danon et al (1981). He was in good health except for WPW syndrome diagnosed at 7 years of age. He had heart murmur with abnormal ECG, elevated serum GOT, GPT, LDH, CK and aldolase levels. An echocardiogram showed obstructive hypertrophic cardiomyopathy. Lysosomal enzyme activities including acid alpha-glucosidase in fibroblasts were within normal limits. In the biopsied biceps brachii muscle, there was a mild variation in fiber size. An approximately 10 percent of myofibers had tiny vacuoles which contained periodic acid Schiff positive granules and were slightly high in acid phosphatase activity. The vacuoles were encircled by membranes with high neuron specific enolase (NSE) and acethylcholin-esterase (AchE) activities. On electron microscopy, numerous autophagic vacuoles scavenging glycogen granules were recognized as seen in acid maltase deficiency. Because the vacuolar membranes were high in NSE and AchE activities, lysosomal membrane formation from the cell membrane may be defective. When one has a patient with mild to moderate mental retardation, idiopathic hypertrophic cardiomyopathy and high serum CK level, muscle biopsy must be performed to rule out the present disorder.
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PMID:[A patient with lysosomal glycogen storage disease with normal acid maltase]. 839 37