What are the other Names for this Condition? (Also known as/Synonyms)

• Andersen Glycogenosis
• Glycogen Storage Disease Type IV
• Glycogenosis Type IV

What is Andersen's Disease? (Definition/Background Information)

• Andersen's Disease is rare, inherited disorder that affects the body's metabolic process of synthesis of an important storage substance, called glycogen, in the body. The condition is also known as Glycogen Storage Disease Type IV (or GSD Type IV)
• Individuals with a family history of the disorder are at risk for developing GSD Type IV. The condition is caused by mutations in the GBE1 gene and inherited in an autosomal recessive manner
• In Andersen's Disease, there is an abnormal storage of glycogen that takes place in the body. This abnormally-stored glycogen cannot be utilized by the body, resulting in the characteristic signs and symptoms of the condition.
• These signs and symptoms include reduced blood glucose, decreased muscle mass, weakness, enlarged liver and spleen, and even heart abnormalities. Andersen’s Disease can affect multiple organs and body systems
• Treatment options for Andersen’s Disease are geared toward addressing the symptoms of the disorder and offering supportive care. For individuals with liver failure, liver transplantation may be recommended
• Since Andersen’s Disease is an inherited disorder, there are no effective ways of preventing its occurrence. However, genetic counseling of prospective parents with a family history of the disorder may help in a better understanding of the disorder and the likelihood of their offspring developing the same
• The prognosis of Andersen’s Disease depends on the severity of the condition. Children with milder forms of the disorder have a better prognosis than those with severe signs and symptoms

Who gets Andersen's Disease? (Age and Sex Distribution)

• Andersen's Disease is a very uncommon condition. The abnormal glycogen storage in the body starts during the early stages of fetal development
• The condition occurs in one in 600,000-800,000 individuals worldwide
• Both genders are reported to be susceptible to the condition
• No distinct geographic, racial or ethnic distribution is reported for the occurrence of Andersen's Disease

What are the Risk Factors for Andersen's Disease? (Predisposing Factors)

• A major risk factor for developing Andersen’s Disease is a family history of the condition

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Andersen's Disease? (Etiology)

Andersen’s Disease is an inherited disorder that occurs due to mutations in the GBE1 gene.

• These mutations in the GBE1 gene result in a deficiency in the glycogen branching enzyme known as amyl-transglucosidase
• Glycogen is an important stored energy source for the body. The defective enzyme results in the formation and accumulation of an abnormal form of glycogen, called polyglucosan (with long, unbranched chains of glucose molecules)
• This accumulation of abnormal glycogen molecules in the tissues and organs (including the liver, muscles, etc.), results in the signs and symptoms of Andersen’s Disease
• Andersen’s Disease is inherited in an autosomal recessive manner, in which two copies of the defective gene must be inherited for an individual to develop the disease

Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children, born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Andersen's Disease?

There are different types of glycogen storage disorders (GSDs) and Andersen's Disease is one of the types. The signs and symptoms usually begin in the first few months of life. Some signs and symptoms associated with Andersen's Disease include:

• Breathing difficulties
• Productive cough with bloody sputum
• Variations in skin tone and color
• Weakness and exhaustion; inability to perform physical activities
• Decreased muscle mass
• Neuromuscular abnormalities
• Developmental delays
• Failure to gain weight and appearing malnourished
• Delayed or impaired mental development
• Heart conditions such as high blood pressure
• Accumulation of fluid in the abdomen
• Joint problems

How is Andersen's Disease Diagnosed?

The diagnosis of Andersen’s Disease is undertaken through the following tests and exams:

• An assessment of the child and the child’s family medical history
• Physical examination and an assessment of symptoms
• Blood tests for examining glucose levels
• Liver function test
• Urine analysis
• Genetic studies: A blood test can be performed to detect the mutation for Andersen's Disease
• Imaging radiological studies to determine organ enlargement, such as abdominal ultrasound for enlarged liver or spleen, and other structural anomalies, as required
• Biopsy of tissue samples, which may include a cheek swab
• Tests for enzyme activity in muscle, liver, and skin cells

Note: In some cases, prenatal diagnosis of the condition may be recommended.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Andersen's Disease?

Some potential complications associated with Andersen's Disease include:

• Scarring of the liver; liver cirrhosis
• Liver failure
• Development of an enlarged spleen (splenomegaly), which reduces the number of blood cells in the body
  • This can result in anemia causing signs and symptoms such as pale skin and fatigue, due to reduced red blood cell count
  • It can also cause thrombocytopenia due to decreased platelet count causing signs and symptoms such as bleeding disorders and easy bruising
• In developing fetus, a condition called ‘hydrops fetalis’ or accumulation of fluid, can lead to brain damage

How is Andersen's Disease Treated?

At the present time, there is no cure for Andersen’s Disease. Treatment is generally targeted at a particular set of symptoms the child may be experiencing.

• Generally, emphasis is given to the maintenance of adequate glucose levels in blood through proper diet
• Undertaking treatment for signs and symptoms due to liver cirrhosis
• For those with progressive liver failure, liver transplantation may be recommended
• For individuals with cardiac abnormalities, medications may be required to manage the condition

Supportive care for the affected individual is considered an important aspect of Andersen’s Disease management.

How can Andersen's Disease be Prevented?

• Currently, there are no specific methods or guidelines to prevent Andersen’s Disease, since it is a genetic condition
• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders such as Andersen’s Disease

Regular medical screening at periodic intervals with tests, and physical examinations are mandatory.

What is the Prognosis of Andersen's Disease? (Outcomes/Resolutions)

The prognosis of Andersen’s Disease depends on the combination of signs and symptoms.

• Children with severe signs and symptoms have poorer prognosis when compared to children with mild signs and symptoms. Studies have shown that in children with severe signs and symptoms, the expected life expectancy is 5 years
• Some individuals develop severe liver abnormalities and enlarged spleen within a few months after birth that get progressively worse. This development has a poor outcome
• Those who get diagnosed later in life and with milder symptoms may have a better prognosis with proper management of symptoms
• Those with progressive liver failure may need liver transplantation. The prognosis in such cases is guarded

Additional and Relevant Useful Information for Andersen's Disease:

There are 8 types of glycogen storage diseases, all of which are related to enzyme deficiencies or defects; Andersen’s Disease is Glycogen Storage Disease Type IV.