Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.4.1.18 (branching enzyme)
 628 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 30-year-old woman with clinical features and biochemical findings of muscle phosphofructokinase deficiency was found to have a very low level of alpha-1,4-glucan:alpha-1,4-glucan-6-transglucosylase (branching enzyme, EC 2.4.1.18) activity in muscle. In contrast, branching enzyme activity in the leukocytes was in the range of control values. After sedimentation of the glycogen from muscle homogenates by centrifugation at 105,000 g, branching enzyme activity in muscle of the patient was similar to that of control subjects. This patient illustrates the possibility of falsely diagnosing branching enzyme deficiency when muscle glycogen content is elevated. It is likely that such an artefact may also cause a false positive diagnosis of branching enzyme deficiency in other metabolic diseases associated with glycogen accumulation.
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PMID:Apparent absence of glycogen branching enzyme activity in phosphofructokinase deficiency. 183 26

In this selective review, we consider a number of unsolved questions regarding the glycogen storage diseases (GSD). Thus, the pathogenesis of Pompe disease (GSD II) is not simply explained by excessive intralysosomal glycogen storage and may relate to a more general dysfunction of autophagy. It is not clear why debrancher deficiency (GSD III) causes fixed myopathy rather than exercise intolerance, unless this is due to the frequent accompanying neuropathy. The infantile neuromuscular presentation of branching enzyme deficiency (GSD IV) is underdiagnosed and is finally getting the attention it deserves. On the other hand, the late-onset variant of GSD IV (adult polyglucosan body disease APBD) is one of several polyglucosan disorders (including Lafora disease) due to different etiologies. We still do not understand the clinical heterogeneity of McArdle disease (GSD V) or the molecular basis of the rare fatal infantile form. Similarly, the multisystemic infantile presentation of phosphofructokinase deficiency (GSD VII) is a conundrum. We observed an interesting association between phosphoglycerate kinase deficiency (GSD IX) and juvenile Parkinsonism, which is probably causal rather than casual. Also unexplained is the frequent and apparently specific association of phosphoglycerate mutase deficiency (GSD X) and tubular aggregates. By paying more attention to problems than to progress, we aimed to look to the future rather than to the past.
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PMID:Progress and problems in muscle glycogenoses. 2210 11