Browsing Pathways

Glutathione Synthetase Deficiency (5-Oxoprolinuria; Pyroglutamic Aciduria; GSD) is a rare inborn error of metabolism (IEM) which arises from a disfunctional gene called GSS. This gene is responsible for glutathione synthetase. Glutathione synthetase is the second enzyme in the glutathione biosynthesis pathway. It catalyses the condensation of gamma-glutamylcysteine and glycine, to form glutathione. A defect in this enzyme results in accumulation of pyroglutamic acid and gamma-glutamylcysteine in urine and blood; decrease level of glutathione in erythrocytes; increase urinary excretion of 5-oxoproline. GSD is typically distinguished by three levels of severity. Those levels naturally being mild, moderate and severe. Being with the former, mild GSD can lead to a harmful condition known as hemolytic anemia. This occurs when red blood cells are destroyed. Although not as common, it is also possible for patients affected with GSD to excrete in their urine elevated quantities of 5-oxoproline (hence the other name for this condition shown in the first sentence of this description). The accumulation of high levels of 5-oxoproline (and hence the elevated level of secretion of this compound) is a direct consequence of glutathione being improperly processed by the body. Turning now to the second level of severity, moderate, it is typical to see affected patients experience experience the two symptoms described above, in addition to metabolic acidosis. The latter condition being the consequence of high acidity levels in the blood as well as other tissues. Finally, individuals with severe GSD may suffer from a wide variety of neurological symptoms. This could include anything from ataxia and slowed reactions, to psychomotor retardation, mental retardation and seizures.

Glycerol Kinase Deficiency (Hyperglycerolemia; Glyceroluria; GK Deficiency; GKD) is a rare metabolic disease caused by a deficiency in the GK gene which codes for glycerol kinase. A deficiency in this enzyme results in accumulation of glycerol in urine and serum. Symptoms include cryptorchism, strabismus, myopathy, lethargy, and vomiting. Treatment includes corticosteroids and acute glucose infusion.

Glycerol Kinase Deficiency (Hyperglycerolemia; Glyceroluria; GK Deficiency; GKD) is a rare metabolic disease caused by a deficiency in the GK gene which codes for glycerol kinase. A deficiency in this enzyme results in accumulation of glycerol in urine and serum. Symptoms include cryptorchism, trabismus, myopathy, lethargy, and vomiting. Treatment includes corticosteroids and acute glucose infusion.

Glycine N-methyltransferase deficiency, also called GNMT deficiency, is an autosomal recessive disorder of methionine metabolism caused by a defective glycine N-methyltransferase (GNMT). GNMT catalyzes the conversion of glycine into N-methylglycine (sarcosine) using S-adenosylmethionine (SAM or AdoMet). This disorder is characterized by a large accumulation of methionine in the plasma and transaminases in the serum. Symptoms of the disorder include hepatomegaly.

Glycine N-methyltransferase deficiency, also called GNMT deficiency, is an autosomal recessive disorder of methionine metabolism caused by a defective glycine N-methyltransferase (GNMT). GNMT catalyzes the conversion of glycine into N-methylglycine (sarcosine) using S-adenosylmethionine (SAM or AdoMet). This disorder is characterized by a large accumulation of methionine in the plasma and transaminases in the serum. Symptoms of the disorder include hepatomegaly.

Glycogen storage disease type 1A (GSD1A), or von Gierke disease, is caused by a defect in the G6PC gene which codes for Glucose-6-phosphatase. Glucose-6-phosphatase hydrolyzes glucose-6-phosphate to glucose and is responsible for the regulation of blood glucose level. A defect in this enzyme results in accumulation of glycogen in affected tissues, like liver and kidney; decreased glucose level; and accumulation of lactate. Glycogen storage disease type 1A causes clinically significant end-organ disease with significant morbidity. Usually it presents in childhood. Symptoms include seizures, irritability, pallor, hypotonia, tremors, loss of consciousness, apnea and hepatomegaly. There is no cure for glycogen storage disease type 1A. Diet therapy can help to prevent hypoglycemia and reduce the symptoms. Liver transplantation may be indicated in cases of hepatic malignancy.

Glycogen storage disease type 1A (GSD1A), or von Gierke disease, is caused by a defect in the G6PC gene which codes for Glucose-6-phosphatase. Glucose-6-phosphatase hydrolyzes glucose-6-phosphate to glucose and is responsible for the regulation of blood glucose level. A defect in this enzyme results in accumulation of glycogen in affected tissues, like liver and kidney; decreased glucose level; and accumulation of lactate. Glycogen storage disease type 1A causes clinically significant end-organ disease with significant morbidity. Usually it presents in childhood. Symptoms include seizures, irritability, pallor, hypotonia, tremors, loss of consciousness, apnea and hepatomegaly. There is no cure for glycogen storage disease type 1A. Diet therapy can help to prevent hypoglycemia and reduce the symptoms. Liver transplantation may be indicated in cases of hepatic malignancy.

Glycogen storage disease, also called glycogenosis and dextrinosis, is a rare inborn error of metabolism (IEM) and recessive disorder, which is caused by a defective glycogen synthase. Glycogen synthase catalyzes the conversion of uridine diphosphate glucose into amylose and uridine 5'-diphosphate which amylose is the substrate of 1,4-alpha-glucan-branching enzyme and glycogen debranching enzyme. This disorder is characterized by a large accumulation of glycogen in the liver or muscles. Symptoms of the disorder depends on the type of glycogen storage disease (e.g. GSD I, GSD III, etc.). Treatments are also depend on the type of glycogen storage disease.

Glycogen storage disease, also called glycogenosis and dextrinosis, is a rare inborn error of metabolism (IEM) and recessive disorder, which is caused by a defective glycogen synthase. Glycogen synthase catalyzes the conversion of uridine diphosphate glucose into amylose and uridine 5'-diphosphate which amylose is the substrate of 1,4-alpha-glucan-branching enzyme and glycogen debranching enzyme. This disorder is characterized by a large accumulation of glycogen in the liver or muscles. Symptoms of the disorder depends on the type of glycogen storage disease (e.g. GSD I, GSD III, etc.). Treatments are also depend on the type of glycogen storage disease.

Glycogenosis, Type IA, also called Von Gierke Disease, is a rare inborn error of metabolism (IEM) and autosomal recessive disorder and caused by a defective glucose-6-phosphatase. Glucose-6-phosphatase catalyzes the conversion of glucose 6-phosphate into D-glucose and conversion of D-glucose to glucose 6-phosphate. Symptoms of the disorder include hypoglycemic seizures, lactic acidosis, hyperuricemia, etc. Treatment with diet management is very effective.