Glycogen debranching enzyme: Difference between revisions

Revision as of 16:21, 16 February 2019

Revision as of 11:39, 2 June 2019

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When GDE activity is compromised, the body cannot effectively release stored glycogen, type III Glycogen Storage Disease (debrancher deficiency), an autosomal recessive disorder, can result. In GSD III glycogen breakdown is incomplete and there is accumulation of abnormal glycogen with short outer branches.<ref name= Monga/>

Most patients exhibit GDE defiency in both liver and muscle (TypeIIIaType IIIa), although 15% of patients have retained GDE in muscle while having it absent from the liver (Type IIIb).<ref name=Hondoh/> Depending on [[mutation]] ___location, different mutations in the AGL gene can affect different isoforms of the [[gene expression]]. For example, mutations that occur on exon 3, affect the form which affect the [[isoform]] that is primarily expressed in the liver; this would lead to GSD type III.<ref name=Shen/>

These different manifestation produce varied symptoms, which can be nearly indistinguishable from Type I GSD, including [[hepatomegaly]], [[hypoglycemia]] in children, short stature, [[myopathy]], and [[cardiomyopathy]].<ref name=Bao/><ref name=Talente/> Type IIIa patients often exhibit symptoms related to liver disease and progressive muscle involvement, with variations caused by age of onset, rate of disease progression and severity. Patients with Type IIIb generally symptoms related to liver disease.<ref name =Kishnan/> Type III patients be distinguished by elevated liver enzymes, with normal [[uric acid]] and blood lactate levels, differing from other forms of GSD.<ref name=Shen/> In patients with muscle involvement, Type IIIa, the muscle weakness becomes predominant into adulthood and can lead to ventricular [[hypertrophy]] and distal muscle wasting.<ref name=Shen/>