Glycogen storage disease type i genetics home reference. The patient may present with hepatomegaly and signs and symptoms of hypoglycemia. Neonatology questions and controversies second edition, 2012. In ordet o get it, it has to be broken down from larger molecules that store it glycogen. Glycogen storage diseases are the result of defects in proteins involved in synthesizing or breaking down glycogen in the blood, cells, and tissues chou et al.
It was the first gsd to have the responsible enzyme defect identified and therefore is designated gsd i. These metabolic diseases may be classified into three main groups, affecting the metabolism of glycogen, galactose, and fructose. Glucose6phosphatase g6pase is an essential, ratelimiting enzyme that serves as a terminal gatekeeper for hepatic glucose release into the plasma. Inborn errors of carbohydrate metabolism knowledge for. The deficiency impairs the ability of the liver to produce free glucose from glycogen and from gluconeogenesis.
Pathway the body needs sugar in the form of glucose to function. Morphological data in type ii disease, large numbers of glycogen containing vacuoles, glycogenosomes, were found in the cytoplasm of the liver cells fig. Symptoms associated with gsdi are attributed to low. The main types of glycogen storage diseases in children are categorized by number and name. Pediatric glycogen storage disease childrens pittsburgh. Detection of heterozygous carriers in glycogen storage. Glycogen is stored in the liver and muscles and is normally broken down into glucose when you do not eat. New players that control the expression of glucose6phosphatase have been identified that. Dec 08, 2010 glycogen storage disease type 1 is an inherited disorder caused by the buildup of a complex sugar called glycogen in the bodys cells. Discussion climcal symptomatology, biochemical and microscopic analysis of liver and muscle biopsy or autopsy materials, permitted precise classification of the present 12 patients with glycogen storage disease into types i a, ii, iii, iv, v, type iii variant of muscle type disease and muscle type phosphorylase b kmase deficiency. This impairment disrupts the livers ability to break down stored glycogen that is necessary to maintain adequate blood sugar levels. Two patients had almost total deficiency of hepatic g6pase. Absence of the src2 coactivator results in a glycogenopathy. Pompe disease glycogen storage disease mnemonic for usmle.
Glycogen storage disease type i an overview sciencedirect. A pdf version is available thanks to the evelina london childrens hospital. Glycogen storage disease type 1a genetic and rare diseases. Affected newborns are at risk of neonatal hypoglycemia low blood. Jan 08, 2019 glycogen storage disease gsd is a rare genetic disorder that affects about one in 20,000 people in the u.
It is still considered the first line of treatment for. It highlights current practices and therapeutic approaches to the diagnosis and management of gsd i and its early and longterm complications. It is normally broken down into glucose to give you more energy when you need it. The diagnosis is supported by blood sugar concentrations following the administration of monosaccharides and following epinephrine injection as well as by postmortem anatomical and chemical studies. Glycogen storage disease type i gsd i is an inherited disease that results in the liver being unable to properly break down stored glycogen.
Photographs were taken after securing a signed informed consent, as registered in the clinical histories of both child patients, to document that exposed. Media in category glycogen storage disease type i the following 6 files are in this category, out of 6 total. Gsds are caused by the enzyme deficiencies effect on glycogen synthesis, glycogen breakdown or glycolysis glucose breakdown, typically within muscles andor liver cells. New players that control the expression of glucose6phosphatase have been identified that may provide insight into. Following removal gierk the phosphate the free glucose is transported out of the er lumen to the cytosol. Diagnosis and management of glycogen storage disease type. Glycogen storage disease type 3 an overview sciencedirect.
Glucose6phosphate levels and liver glycogen disease. The types may be divided loosely into those where the enzymic lesion, and hence the accumulation ofpolysaccharide, are localized types i, v, vii, and those where a more generalized distribution amongst tissues is seen types ii, iii, iv, vi. The accumulation of glycogen in certain organs and tissues, especially the liver, kidneys, and small intestines, impairs their ability to function normally. Quizlet flashcards, activities and games help you improve your grades. Covering pathophysiology, sign, symptoms, clinical findings as well fgteev im a gurkey turkey feat. The severity of the hypoglycemia and lactic acidosis can be such that in the past affected individuals died in infancy. Glycogen is a form of sugar glucose that is stored in the liver and muscles. Diet is the mainstay of treatment and requires close monitoring and adjustment by a highly specialized. There is hypoglycemia and excess glycogen is stored in liver, kidney causing illness. There is an enzyme defect in glucose6phosphatase so that glucose6phosphate cannot be converted into free glucose but is metabolised to lactic acid or incorporated into glycogen. Glycogen storage disease type iii gsdiii is an autosomal recessive disorder caused by a deficiency of glycogen debranching enzyme activity, leading to the accumulation of glycogen in the liver and muscle. Christensen md, in hematology, immunology and infectious disease.
Molecular diagnosis of glycogen storage disease type i. They claimed that children with this disease, and their parents, have. Glycogen storage disease gsd is a rare genetic disorder that affects about one in 20,000 people in the u. Longterm complications are usually only seen now in adults whose disease was poorly treated early on. Glucose6phosphate levels and liver glycogen disease jama. During fasting, the normal conversion of triglycerides to free. The defective enzymes involved in gsd i are mainly active in the liver and kidney. There is no report regarding ethnic difference in the incidence of gsd type i, however there are different types of mutations in caucasian, hispanic, asian and jewish populations ekstein et al. Jul 12, 2018 pompe disease, also called glycogen storage disease type ii gsdii, is an autosomal recessive metabolic disorder that damages muscle and nerve cells throughout the body. Nov 28, 2008 hepatic glucose production is critical for basal brain function and survival when dietary glucose is unavailable.
Type 1 glycogen storage disease gsd1 is an autosomal recessive disorder that was first described in 1929 by e. Hyperuricemia in glycogenstorage disease type 1 jama. Hello guys, this is what wiki says, hypertriglyceridemia resulting from amplified triglyceride production is another indirect effect of impaired gluconeogenesis, amplified by chronically low insulin levels. Patients with type 1 glycogen storage disease can present during the neonatal period with lactic acidosis and hypoglycemia.
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