Pompe disease
Glycogen storage disease type II, also called Pompe disease, is an autosomal recessive disease that results from the deficiency of acid alpha-glucosidase – lysosomal hydrolase .
There are three main forms of the disease – infantile, juvenile and emerging in adulthood.
The infantile form appears at about 6 months of age and is characterized by its rapid progression and fatal outcome. In these cases, cardiac, skeletal and respiratory muscles are affected.
Respiratory and cardiac failure are the usual causes of death. The adult-onset form is a slowly progressive disease in which the heart is not affected.
In those affected, it manifests as proximal muscle weakness between the second and sixth decades of life.
Like the infantile form, patients with the adult form eventually develop respiratory failure.
In the juvenile or intermediate form babies and children over 6 months of age are affected.
In them, the disease manifests itself as weakness, but usually heart disease does not develop, as well as the clinical features of the other two forms.
Therefore, the later in life the disease occurs, the less likely it is to develop a heart complication.
What are the symptoms?
Infantile form:
• Cardiomegaly and congestive heart failure;
• Generalized hypotension, absent or reduced reflexes;
• Enlarged tongue and increased liver size;
• Reflexes may be suppressed or completely absent due to accumulation of glycogen in the spinal motor neurons;
• Impaired ability to direct attention;
Age form:
Feelings of weakness may only affect certain muscle groups, such as the upper arms, and may be asymmetrical.
What are the complications?
Infantile form:
• Cardiomegaly and congestive heart failure can cause death. Enlargement of the heart muscle accompanied by progressive left ventricular obstruction and rupture is the main cause of death.
• Aspiration pneumonia – the weakness of the respiratory muscles increases the risk of developing pneumonia;
In the elderly form of the disease, intracranial aneurysms represent the most serious complication. Liver failure may occur
Treatment of Pompe disease
Enzyme replacement therapy has been shown to be very effective and significantly improves the outlook for patients.
The alpha glucosidase enzyme, which is produced by recombinant DNA technology, is licensed for long-term replacement therapy for the disease.
Alpha glucosidase therapy has been shown to improve cardiac and skeletal muscle function.
The therapy has also been shown to significantly reduce the risk of death and the need for invasive ventilation among treated patients.
Treatment of heart and respiratory failure may be required. A change in diet may provide some improvement, but will not lead to a more favorable course of the disease.
A diet that includes foods high in protein and low in carbohydrates is beneficial for the disease.
Sometimes it is necessary to appoint physiotherapy and occupational therapy.
Fetal morphology and prenatal diagnostics such as chorionic biopsy and amniocentesis can be used to determine enzyme activity in the fetus.
Gene therapy remains a potentially effective treatment in the future.
Prognosis
Without enzyme-replacement therapy, the infantile form is usually fatal, with most deaths occurring within the first year after birth.
In case of later clinical onset of the disease, it proceeds more favorably and with much less pronounced symptoms.
The age-related form is not necessarily fatal, but complications such as aneurysm rupture or respiratory failure may cause severe illness and death.
