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)

We describe a boy with an early lethal hypertrophic vacuolar cardiomyopathy of neonatal onset. Abnormal intra- and extralysosomal glycogen storage disease was demonstrated in heart and skeletal muscles. Glycogen content was twice the normal in muscles and over 3-fold the normal in the heart. In this organ, over 50% of the intracellular space was occupied by glycogen and possibly oligosaccharides, as demonstrated by the quantitative morphometric analysis of electron micrographs. The activity of acid alpha-glucosidase was increased in the heart, skeletal muscles, and liver, but was normal in leukocytes. A review of the 11 previously published pedigrees of lysosomal glycogen storage disease with normal in vitro alpha-glucosidase activity allows the delineation of three clinical entities: juvenile and neonatal pseudo-Pompe diseases and partial Pompe disease. Partial Pompe disease, due to the tissue-specific absence of acid alpha-glucosidase, was observed in a single patient. The most common form is the late-onset pseudo-Pompe disease, which is characterized by severe cardiomyopathy and mild myopathy appearing in the second or third decade, prominent arrhythmia with Wolf-Parkinson-White syndrome, and sometimes mental retardation. Patients reported as suffering from Antopol disease probably belong to this group. Dominant inheritance (autosomal or X linked) is likely in most families. The present report appears to be the first one to describe a rapidly fatal neonatal form of lysosomal glycogenosis without acid maltase deficiency. The mode of inheritance of this form is not known. Differential diagosis includes Pompe disease (similar histology) and cardiac phosphorylase b kinase deficiency (similar clinical course). The delineation of neonatal pseudo-Pompe disease makes enzymatic confirmation mandatory in each case suspected of Pompe disease.
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PMID:Nosology of lysosomal glycogen storage diseases without in vitro acid maltase deficiency. Delineation of a neonatal form. 938 33

A 29-year-old male who had a past history of mild ECG abnormality of arrhythmia at the age of 14 years, was referred to our hospital because of elevated serum creatine kinase (CK) level. He had never been aware of muscular weakness nor cardiac symptoms. Neurological examination revealed normal muscle strength of all extremities except marked back muscle weakness. He had normal intelligence. On laboratory examination, serum AST, ALT, LDH, aldolase, CK and myoglobin levels were elevated. Both lactate and pyruvate levels were normally responded after an ischemic exercises test. Acid maltase activity was normal in white blood cells. A muscle biopsy obtained from rectus femoris muscle revealed vacuolar myopathy with mildly increased PAS positive material. On electron microscopy, there were autophagic vacuoles scavenging glycogen particles and cytoplasmic debris, and sarcolemmal indentation, compatible with the findings of lysosomal glycogen storage disease with normal acid maltase. This patient had unusual clinical features of absent mental retardation and no apparent cardiomyopathy. Accordingly, mental retardation is probably not necessary to see later onset of cardiac muscle involvement.
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PMID:[Lysosomal glycogen storage disease with normal acid maltase (Danon) without apparent cardiomyopathy and mental retardation]. 1088 38

Danon disease ('lysosomal glycogen storage disease with normal acid maltase') is characterized by a cardiomyopathy, myopathy and variable mental retardation. Mutations in the coding sequence of the lysosomal-associated membrane protein 2 (LAMP-2) were shown to cause a LAMP-2 deficiency in patients with Danon disease. LAMP-2 deficient mice manifest a similar vacuolar cardioskeletal myopathy. In addition to the patient reports LAMP-2 deficiency in mice causes pancreatic, hepatocytic, endothelial and leucocyte vacuolation. LAMP-2 deficient mice represent a valuable animal model of Danon disease. They will further be used to study the exact role of LAMP-2 in autophagy and to analyse the consequences of an impaired autophagic pathway in various tissues.
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PMID:Disease model: LAMP-2 enlightens Danon disease. 1142 88

Herein, we report a new case of Danon's disease in a 41-year-old Frenchman. This patient displays the typical clinical triad, with cardiomyopathy, mental retardation and myopathy, and a vacuolar myopathy without acid alpha-glucosidase deficiency. He has also developed a diffuse chorio-capillary ocular atrophy, and represents the second case of successful heart transplantation in this lysosomal disease. Interestingly, analysis of LAMP-2 protein expression in cultured fibroblasts revealed a primary deficiency of this lysosomal membrane protein. This defect resulted from a yet undescribed deletion in exon 7 of lamp-2 gene.
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PMID:Danon's disease (X-linked vacuolar cardiomyopathy and myopathy): a case with a novel Lamp-2 gene mutation. 1239 43

Danon disease (DD) is a rare lysosomal glycogen storage disease with normal acid maltase activity, which is characterised clinically by cardiomyopathy and myopathy, and a variable degree of mental retardation. The causative gene, LAMP2, has been mapped to chromosome Xq24-q25. LAMP2 encodes a lysosome-associated membrane glycoprotein. We identified a novel LAMP2 mutation of the exon 8 splice acceptor site (IVS7-1G --> A) in an affected male and female, which predicts abnormal splicing. Both affected individuals presented solely with hypertrophic cardiomyopathy. Muscle weakness and mental impairment were absent. Diagnosis of Danon disease was established by muscle biopsy, when the male index patient developed transient severe muscle weakness following heart transplantation. Typical biopsy findings were also found in a heart muscle specimen. Demonstration of the LAMP2 mutation in affected male and female siblings is compatible with X-linked dominant inheritance. Danon disease should be actively looked for in cardiomyopathy patients.
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PMID:Identification of a novel LAMP2 mutation responsible for X-chromosomal dominant Danon disease. 1459 34

Glycogen storage disease type II (GSD-II), also known as Pompe disease, is a rare autosomial recessive disease due to deficiency of lysosomal acid alpha-glucosidase (GAA). The infantile-onset form is the most severe, and most patients present with hypotonia and cardiomyopathy in early infancy. We report on a typical case of Pompe disease in a patient who died at 8 months of age due to aspiration pneumonia and hypertrophic cardiomyopathy. Genetic studies showed deficient GAA activity and mutation of the GAA gene with Gly615Arg (exon 13, G1845A). On autopsy, glycogen had markedly accumulated in the liver, myocardium and skeletal muscle. The neurons of the anterior horn of the spinal cord and medulla were also involved, but the cortex was spared. These neurological-histologic findings may explain the clinical features of poor motor function, decreased deep tendon reflexes and lack of mental retardation.
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PMID:Infantile-onset glycogen storage disease type II (Pompe disease): report of a case with genetic diagnosis and pathological findings. 1536 15

Danon disease is an X-linked cardioskeletal myopathy, originally reported as "lysosomal glycogen storage disease with normal acid maltase," resulting from a primary deficiency of lysosome-associated membrane protein-2 because of mutations in the lysosome-associated membrane protein-2 gene. Classic clinical features in males include cardiomyopathy (100%, eventually), myopathy (90%), and mental retardation (70%), but mostly of a mild degree. We report on an unusual presentation in a patient with autism, motor delay, and a normal cardiac evaluation. The presence of multiorgan involvement, including elevated liver enzymes, abnormal cranial magnetic resonance imaging, and diffuse hypotonia with swallowing difficulties, prompted a muscle biopsy. A quadriceps muscle biopsy was performed, and the findings were most suspicious for a glycogen storage-type disease. Subsequently, a pathogenic lysosome-associated membrane protein-2 mutation was found. To our knowledge, there are no previous clinical reports of autism in children with Danon disease.
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PMID:Danon disease: an unusual presentation of autism. 1855 74


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