Mucopolysaccharidosis Type VII (MPS VII Sly syndrome)
Description
Mucopolysaccharidosis Type VII (MPS VII), also known as Sly syndrome, is a rare genetic disorder that affects the body‘s ability to break down complex sugar molecules called glycosaminoglycans (GAGs). These GAGs accumulate in various tissues, particularly in bone, cartilage, and other connective tissues, leading to a range of health problems. This blog post will delve into the intricacies of MPS VII, exploring its causes, signs and symptoms, diagnosis, management approaches, and ways to thrive with this condition.
Genes Involved
Genes Involved:
MPS VII is caused by mutations in the β-glucuronidase (GUSB) gene located on chromosome 7. This gene provides instructions for producing the β-glucuronidase enzyme, which is essential for breaking down GAGs.
Recognizing the Signs and Symptoms
Recognizing the Signs and Symptoms:
MPS VII can manifest with a diverse range of symptoms, varying in severity from mild to severe. Common signs include:
- Skeletal Abnormalities: Short stature, joint stiffness, bone deformities (e.g., scoliosis, kyphosis), and fragile bones are characteristic features.
- Facial Features: A distinctive facial appearance with a broad forehead, flat nasal bridge, and a prominent tongue may be present.
- Respiratory Issues: Recurrent respiratory infections, airway obstruction, and sleep apnea can occur due to GAG accumulation in the airways.
- Cardiovascular Complications: Valvular heart disease, thickened heart walls, and enlarged hearts can arise from GAG deposits in the cardiovascular system.
- Hepatosplenomegaly: An enlarged liver and spleen may be present due to GAG buildup in these organs.
- Neurological Manifestations: Developmental delays, intellectual disabilities, hearing loss, and vision problems can occur in some cases.
- Other Symptoms: Corneal clouding (opacity of the cornea), coarse facial features, and skin abnormalities can also be seen.
Causes
Causes:
MPS VII is an inherited genetic disorder. This means it is passed down from parents to their children. In most cases, both parents are carriers of a faulty gene, but they themselves do not have the disease. If both parents carry the gene, there is a 25% chance their child will inherit two faulty genes and develop MPS VII.
Inheritance/recurrence risk
Inheritance or Recurrence Risk:
MPS VII follows an autosomal recessive inheritance pattern. This means that an individual must inherit two copies of the faulty gene, one from each parent, to develop the disorder. If both parents are carriers, there is a 25% chance their child will inherit the condition. For each subsequent pregnancy, the risk of having a child with MPS VII remains the same at 25%.
