Pompe Disease (Infantile-Onset)
Description
Pompe disease, also known as glycogen storage disease type II (GSDII), is a rare, inherited disorder that affects muscle function. In its most severe form, infantile-onset Pompe disease, symptoms appear early in life, leading to progressive muscle weakness, breathing difficulties, and heart problems. This blog delves into the complexities of this devastating condition, exploring its causes, diagnosis, management, and the hope for a brighter future for individuals with Pompe disease.
Genes Involved
Pompe disease is caused by mutations in the gene that produces the enzyme acid alpha-glucosidase (GAA). This enzyme is crucial for breaking down glycogen, a type of stored sugar, within the body‘s cells. The GAA gene is located on chromosome 17.
Recognizing the Signs and Symptoms
Infantile-onset Pompe disease is characterized by a range of symptoms that typically emerge within the first few months of life. These symptoms include:
- Muscle weakness: A noticeable lack of muscle strength, often leading to delayed motor development, such as rolling over, sitting up, or crawling.
- Breathing difficulties: Respiratory problems due to weakness in the diaphragm and other breathing muscles, resulting in labored breathing and potential respiratory failure.
- Enlarged heart (cardiomegaly): The heart muscle weakens, leading to an enlarged heart, which can cause heart failure.
- Hypotonia: Reduced muscle tone, making the baby feel floppy and loose.
- Feeding difficulties: Difficulty sucking and swallowing due to weak muscles in the mouth and throat.
- Delayed growth: Infants with Pompe disease may not gain weight or grow as expected.
- Swollen liver: The liver may become enlarged due to the buildup of glycogen.
Causes
Pompe disease is an autosomal recessive disorder. This means that an individual must inherit two copies of the mutated gene, one from each parent, to develop the condition. If an individual inherits one copy of the mutated gene, they are considered a carrier but will not have symptoms. There are many different mutations in the GAA gene that can cause Pompe disease.
Inheritance/recurrence risk
If both parents are carriers of the mutated GAA gene, there is a 25% chance with each pregnancy that their child will inherit two copies of the mutated gene and develop Pompe disease. There is a 50% chance that their child will inherit one copy of the mutated gene and be a carrier. There is a 25% chance that their child will inherit two normal copies of the gene and be unaffected. Genetic counseling is essential for families with a history of Pompe disease to understand the risk of recurrence.
