In this type the enzyme glucose-6-phosphatase is defective in the liver, kidney, and small intestine, where it normally functions. However, the metabolic problem is centered in the liver.
It is an inborn error of metabolism that belongs to lysosomal storage disorders. Every cell in our body contains vesicles called lysosomes those digest the waste products of the cell.
In this glycogen storage disease, the enzyme deficiency causes the body to form glycogen molecules that have an abnormal structure. This abnormal structure also prevents the glycogen from being broken down into free glucose.
In this type, there is not an increased amount of glycogen in the tissues, as in other forms of GSD. Instead, the glycogen that does accumulate has very long outer branches, because there is a genetic deficiency of the branching enzyme.
The phosphorylase enzyme plays a vital role in the breakdown of glycogen into glucose. In the absence of phosphorylase in muscles, glucose can not be released from the glycogen stored in skeletal muscles to create energy. People with Type V GSD experience problems performing and completing most exercises, especially anaerobic exercises. Because they lack the enzyme to metabolize glycogen, which is the main source of energy for anaerobic activity, their body struggles to find other sources of energy to complete a given activity or exercise.
The phosphorylase enzyme plays a vital role in the breakdown of glycogen into glucose. With a deficiency of the liver phosphorylase enzyme, glycogen cannot be broken down to glucose, and the accumulating glycogen results in an enlarged liver. A total deficiency of this liver enzyme would not likely be compatible with life, thus patients with Type VI GSD actually have only partial deficiency of the enzyme.
The phosphofructokinase enzyme is needed to facilitate the breakdown of glycogen into energy in muscle. Patients with this type of GSD have a deficient amount of this enzyme in their muscle tissue. With this deficiency, effective glycogen breakdown (glycolysis) during muscle stress cannot be accomplished, resulting in pain, weakness, and cramping in the exercising muscle.
Patients with this type of glycogen storage disease have a deficiency of the phosphorylase kinase enzyme. The phosphorylase kinase enzyme is a regulatory enzyme in the breakdown of glycogen, thus the deficiency of this enzyme results in glycogen accumulation.
Type 0 glycogen storage disease (GSD 0) is caused by a deficiency in glycogen synthase, an enzyme critical for adequate glycogen synthesis. As a result, there is a marked decrease in glycogen stores resulting in fasting hypoglycemia and post-prandial hyperglycemia. Dietary carbohydrates are preferentially converted to lactate.
Hidradenitis is a chronic inflammation of the apocrine glands, a type of sweat gland found on certain parts of the body. One or more red, tender swellings (lesions) may appear and fill with pus, typically in the areas of the groin, armpits or buttocks. The lesions enlarge and often open and drain on their own. Sometimes, a doctor needs to drain them. Scarring may result. Multiple blackheads (comedones) also are present in the affected areas.