Juvenile Glycogenosis Type II – Causes, Symptoms & Treatment

Juvenile Glycogenosis Type II

Juvenile glycogenosis type II is a glycogen storage disease . It is also known as Pompe disease.

What is Juvenile Glycogenosis Type II?

Juvenile glycogenosis type II is a rare metabolic disease that is hereditary. Because it primarily occurs in the muscles, physicians also count it among the myopathies. Other designations for juvenile glycogenosis type II are Pompe disease , Pompe disease , Pompe disease , generalized glycogenosis or malignant glycogenosis .

The term Pompe disease goes back to the Dutch physician Johannes Cassanius Pompe (1901-1945). He first described the disease in 1932. In 1963, HG Hers found that the lack of lysosomal alpha-glucosidase is responsible for juvenile glycogenosis type II. The adult form of Pompe disease was described by AG Engel in 1969. Juvenile glycogenosis type II occurs only very rarely. In Germany there are only 100 to 200 people who suffer from the hereditary disease. Around the world there are said to be between 5,000 and 10,000 people.


Juvenile glycogenosis type II is caused by a genetic defect. This means that the enzyme alpha-glucosidase, also known as acid maltase, is only produced in insufficient quantities or not at all by the organism. Normally, the enzyme’s function is to break down glycogen . Glycogen is a special form of sugar.It is stored in the muscles of the skeleton and the heart. Small cell organelles that function as an intermediate storage facility are described as lysosomes. If there is an excess of glycogen within the lysosomes, this results in impairment of the cells, which has a negative effect on the entire musculature.

Because glycogen accumulates in the lysosomes, it is called a lysosomal storage disease . The gene for the alpha-glucosidase blueprint is present on chromosome 17. A defect in the alpha-glucosidase gene in both the mother and father is required for the onset of juvenile glycogenosis type II. Pompe disease is one of the autosomal recessive hereditary diseases.

Symptoms, Ailments & Signs

Pompe disease can be divided into three degrees of severity. In addition to the juvenile (late childhood) glycogenosis, this also includes the infantile (early childhood) and the adult (adult) form. Infantile glycogenosis is when the disease begins shortly after birth.

The affected babies suffer from severe muscle weakness , breathing problems , sedentary lifestyle, swallowing disorders , enlarged heart, liver and tongue as well as heart failure . The juvenile form often ends fatally for the sick infants.

Juvenile glycogenosis type II, on the other hand, only becomes apparent in early childhood. It is characterized by gait disturbances and increasing muscle weakness. In addition, the weakened respiratory muscles can lead to respiratory infections and breathing difficulties. The heart is rarely affected in this form. In adult glycogenosis, symptoms such as muscle weakness only appear in adulthood.

Diagnosis & disease progression

Since juvenile glycogenosis type II is a very rare disease, it must first be considered as a possibility by the treating physician. In principle, however, the diagnosis can be made relatively easily with a blood test . The white blood cells are examined for a defect in the alpha-glucosidase enzyme and a high content of glycogen.

Another diagnostic option is to take a tissue sample . This can also be checked for glycogen content and alpha-glucosidase activity. One of the abnormalities that can be seen microscopically is the enlargement of the lysosomes. A skin sample is also possible, from which connective tissue cells are cultivated.

The course of juvenile glycogenosis type II varies and cannot be predicted. Both mild and severe disease progressions can occur. If the course is severe, those affected are no longer able to move independently and often require artificial respiration. The sooner Pompe disease occurs, the less favorable the course of the disease. However, mental abilities are not affected by glycogenosis.


Type II glycogenosis usually causes a number of different symptoms. Most patients suffer primarily from swallowing disorders and breathing difficulties. The muscles can also be severely weakened and heart failure can occur.In the worst case, this can lead to the death of the patient, especially if no early treatment is initiated. There are also severe gait disorders and restricted mobility. Type II glycogenosis can also infect the airways, potentially reducing life expectancy. In many cases, the symptoms only appear in adulthood, so that an early diagnosis is not possible.

Type II glycogenosis can be treated relatively well with medication. Usually there are no special complications. Furthermore, acute emergencies can also be treated directly by an emergency doctor. This is the case when there is a severe headache or dizziness. In this case, the person concerned can also lose consciousness and possibly injure themselves in the event of a fall. It is not uncommon for rashes to appear on the skin.

When should you go to the doctor?

Breathing problems must always be examined by the person concerned as quickly as possible. If the body is undersupplied with oxygen over a longer period of time, life-threatening conditions can develop that require a timely response. In severe cases, an emergency service should be alerted in the event of a respiratory failure. If fears arise or if family members notice interruptions in breathing during the night’s sleep, a doctor must be consulted. If you have trouble swallowing, refuse to eat, or lose weight, see a doctor.

If the body does not get enough liquid for several days due to the symptoms, a feeling of inner dryness develops. A doctor’s visit must be made immediately, since dehydration threatens the premature death of the person concerned. If there is a reduced development of the muscles, there is a lack of movement or apathetic behavior, a doctor is needed.

The symptoms described can occur in both children and adults. To avoid sudden death, it is necessary to consult a doctor as soon as the first warning signs appear. Swelling of the chest, a feeling of tightness inside the body or a diffuse feeling of illness should be presented to a doctor. If there is an unsteady gait, an enlarged tongue or cardiac arrhythmia, a doctor’s visit is also necessary.

Treatment & Therapy

Since 2006, juvenile glycogenosis type II has been treated in Germany with enzyme replacement therapy (ERT) using Myozymes. The therapy is carried out in all patients in whom the diagnosis of Pompe disease has been confirmed. As part of the treatment, the patient is given the missing alpha-glucosidase enzyme every two weeks. It is administered through an intravenous infusion.

The enzyme is transported to the cells via the bloodstream. Once there, it attaches itself to the lysosym receptors, allowing it to penetrate into the interior of the lysosome. Metabolism is similar in healthy people. The effectiveness of enzyme replacement therapy is difficult to assess. So it depends on the starting position.

An early start of therapy is considered to be crucial for the success of the treatment. The infusion is given on an outpatient basis, so hospitalization is not usually required. Sometimes the infusions can cause side effects that occur about two hours after the treatment. These include dizziness , skin rashes , coughing , nausea or headaches . Allergic reactions are also possible.

Outlook & Forecast

A cure of the disease is impossible with the previous medical and legal possibilities. The patient has a causal genetic defect which, for legal reasons, cannot be changed. The treatment of the physicians is therefore aimed at relieving the existing symptoms and in particular at supplying the missing enzyme. Lifelong therapy is necessary to achieve stabilization of health. Once treatment is stopped, the patient’s health will deteriorate within a few days or weeks.

The sooner a diagnosis is made and enzyme replacement therapy is initiated, the better the chance of alleviating the symptoms that have occurred. Despite all efforts, a complete avoidance of symptoms is not currently achieved. A restriction of quality of life and well-being remains. In addition, side effects can occur. Since the missing enzyme is supplied to the organism via the bloodstream every 14 days, side effects or complications can occur at any time. The general risk of infection is also increased in patients due to the circumstances.

Although there are various risks associated with the use of this form of therapy, it still represents the best treatment option based on current scientific knowledge. The prognosis is worsened as soon as a patient shows an allergic reaction immediately after treatment.


Juvenile glycogenosis type II is an inherited disease. For this reason, prevention is not possible. Couples affected by Pompe disease who wish to have children are advised to seek genetic counseling.


Juvenile glycogenosis type II can only be treated in aftercare with the necessary medical instruction. There are no preventive measures for the hereditary disease, which is why genetic counseling is recommended for affected couples who wish to have children. The relatively rare disease requires close medical care.

In order to keep the risk for the patient low, you should always consult your doctor before you take any self-help measures. Those affected are extremely susceptible to respiratory infections, which is why preventing such diseases plays an important role. Especially in the cold winter months, patients must not come into contact with infected people.

Quitting smoking is definitely a good idea. Some patients suffer from muscular weakness. In this case, the doctor recommends physiotherapy. The patients should do the corresponding exercises regularly, which can also be done at home after an introduction by a trainer.

Here, too, there is a precise agreement with the therapist and the doctor beforehand, so that the body is not put under too much strain. The medication prescribed by the doctor must be taken regularly and exactly as directed. Through this cooperation, the patients can perceive an improvement, even if the disease cannot be cured.

You can do that yourself

Juvenile glycogenosis type II is a comparatively rare disease that must always be treated and cared for by a specialist. Therefore, any self-help measures must first be coordinated with the treating physician in order not to endanger the patient. In general, the people affected suffer from a particular susceptibility to infections of the respiratory tract. It therefore makes sense for patients to pay more attention to the prevention of such diseases. During the cold season in particular, patients avoid contact with those who are infected. They also generally abstain from smoking .

Some of those affected suffer from muscle weakness, so that physiotherapy treatment is of great importance for the quality of life. The patients can also carry out the exercises they have learned at home without the help of the trainer, but only if this is expressly permitted by the therapist.

Various drugs are now available for drug therapy, so that patients receive relatively good treatment. A prerequisite for successful therapy is the cooperation of the patients, who always attend the medical examination appointments with various specialists.

Lisa Newlon
 | Website

Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.