User:Noorulain Fatima/sandbox

FORBES DISEASE
Forbes disease(GSD III) is one among the many Glycogen Storage Disorders caused due to the deficiency of the Debrancher enzyme,namely, Amylo-1,6-glucosidase. By definition, a debranching enzyme, is involved in the breakdown of glycogen. And hence helps in the conversion of the glycogen(stored in liver and muscle) to the readily available form of energy i.e. glucose. In absence/deficiency of the debrancher enzyme, the glycogen is only broken down partially and the structure obtained a molecule called 'limit dextrin' which gets accumulated in the liver and muscle cells. Hence Forbes disease is also known as Limit Dextrinosis. Other Names include: -Cori Disease -Glycogenosis Type III -Amylo-1,6-glucosidase deficiency GSDIII is classified into 4 categories based on the symptoms it produces, namely GSDIIIa, GSDIIIb, GSDIIIc, and GSDIIId. In types IIIa and IIIc, both the liver and the muscles are affected while in types IIIb and IIId only the liver is affected.



Causes:
Debrancher deficiency is caused due to the defective gene- gene map locus 1p21. It is an autosomal recessive disorder and hence consanguineous mating might be the cause. All GSDs together affect less than 1 in 40,000 persons in the U.S.

Signs and symptoms-
Disease can begin at any time during the lifetime of the individual and is slowly progressive. The infantile onset maybe life-threatening in childhood. Symptoms of the disease during the first few years of life are indistinguishable from other GSDs. Some of the common symptoms include: •	Hepatomegaly

•	Hypoglycemia

•	Hyperlipemia

•	Cirrhosis(few cases)

•	Myopathy (including cardiomyopathy in a few cases) Hepatomegaly is the enlargement of the liver caused due to the abnormally high amount of glycogen. Also, since glycogen is not converted to glucose, patients also have low blood sugar level (hypoglycemia) and high amount of fatty substances (hyperlipemia). Some individuals maybe asymptomatic except having a protruding abdomen and an enlarged stomach and tend to lose them during adolescence and their liver reverts to its original size. Children with Cori disease often grow slowly during childhood and puberty maybe delayed but their adult height is usually normal. People with this disorder maybe expected to live a normal life span.

Diagnosis:
Presence is definite if the biopsies of the liver and muscle tissues test positive for abnormal glucose and debrancher enzyme levels.

Treatment:
•	Intravenous drips to avoid hypoglycemia

•	Frequent small servings of carbohydrate and a high protein diet are advisable during the day.

•	Genetic counseling for families with children having GSD.

Other Glycogen Storage Disorders:
•	Von Gierke disease

•	Anderson Disease

•	Hers Disease