Which GSD is due to the deficiency glucose-6-phosphatase?

Which GSD is due to the deficiency glucose-6-phosphatase?

Glucose-6-phosphatase deficiency (G6PD, MIM #232200), also known as von Gierke disease, is a glycogen storage disease (GSD). It was the first GSD to have the responsible enzyme defect identified and therefore is designated GSD I (table 1).

What are glycogen storage diseases?

Glycogen storage disease (GSD) is a rare condition that changes the way the body uses and stores glycogen, a form of sugar or glucose. Glycogen is a main source of energy for the body. Glycogen is stored in the liver. When the body needs more energy, certain proteins called enzymes break down glycogen into glucose.

Why does muscle not have glucose-6-phosphatase?

Thus, glucose 6-phosphate generated from glycogenolysis and glucogenesis is released from the liver into the circulation for peripheral use. There does not appear to be glucose 6-phosphatase in skeletal muscle; hence, muscle glycogen is not a source of circulating glucose.

Is glucose-6-phosphatase the same as glucose-6-phosphate dehydrogenase?

Glucose 6-phosphatase (EC 3.1. 3.9, G6Pase) is an enzyme that hydrolyzes glucose 6-phosphate, resulting in the creation of a phosphate group and free glucose. Glucose is then exported from the cell via glucose transporter membrane proteins.

Which GSD is characterized by cardiomegaly?

GSD type II Conspicuous cardiomegaly with cardiomyopathy and heart failure may be present.

How is glycogen storage disorder diagnosed?

Abdominal ultrasound – To see if your liver is enlarged. Tissue biopsy – Testing a sample of tissue from a muscle or your liver to measure the level of glycogen or enzymes present. Gene testing – To look for problems with the genes for different enzymes. Gene testing can confirm a GSD.

Does insulin inhibit glucose-6-phosphatase?

ABSTRACT. The expression of glucose-6-phosphatase (G6Pase) mRNA is repressed by insulin and stimulated by cAMP and dexamethasone, with the insulin effect dominant.

Do muscles have g6p?

In addition to these two metabolic pathways, glucose 6-phosphate may also be converted to glycogen or starch for storage. This storage is in the liver and muscles in the form of glycogen for most multicellular animals, and in intracellular starch or glycogen granules for most other organisms.

What is the pattern of expression of the G6PC3 gene?

The three G6PC genes have different tissue-specific patterns of expression. Only G6PC is expressed at significant levels in adult liver. G6PC2 is expressed predominantly in pancreas and mutations in this gene lead to aberrant glucose signaling and insulin secretion. G6PC3 is expressed in all tissue types examined so far.

What chromosome is G6PC located on?

The gene G6PC, which encodes the liver catalytic subunit of glucose-6-phosphatase, is located on chromosome 17 at band q21. It has five exons and is 12.5 kb in length. It encodes a 35.5-kDa protein consisting of 357 amino acids with no known splice variants.

What is the pathophysiology of neutropenia caused by G6PC3 and G6PT mutations?

The neutropenia in patients with G6PC3 or G6PT mutations is a metabolite-repair deficiency. Microarrays revealed that G6PC mRNA was upregulated following GDNF-mediated dopaminergic differentiation of SH-SY5Y cells. Array association analysis showed three downregulated microRNAs that could possibly influence G6PC translation.

How many exons are there in G6PC?

It has five exons and is 12.5 kb in length. It encodes a 35.5-kDa protein consisting of 357 amino acids with no known splice variants. To date, over 75 different mutations in G6PC have been found in GSD1a patients and are responsible for 80% of cases.