Morquio B Syndrome

Description

Morquio B Syndrome, also known as mucopolysaccharidosis type IVB, is a rare genetic disorder that affects the body‘s ability to break down certain complex sugars called glycosaminoglycans (GAGs). This buildup of GAGs primarily affects the skeletal system, causing a variety of symptoms including short stature, skeletal abnormalities, and joint problems. Understanding Morquio B Syndrome is crucial for early diagnosis, effective management, and helping individuals thrive with this condition.

Genes Involved

Morquio B Syndrome is caused by mutations in the GALNS gene. This gene provides instructions for making an enzyme called N-acetylgalactosamine-6-sulfatase. This enzyme is crucial for breaking down a specific GAG called keratan sulfate. Without this enzyme, keratan sulfate accumulates in the body, leading to the symptoms of Morquio B Syndrome.

Recognizing the Signs and Symptoms

Recognizing the Signs and Symptoms of Morquio B Syndrome can be challenging as they often manifest gradually. Common signs include:

  • Short stature: This is usually the most prominent symptom, with individuals with Morquio B Syndrome often remaining shorter than average throughout their lives.
  • Skeletal abnormalities: These can include a barrel-shaped chest, a prominent forehead, a humpback, and a shortened neck.
  • Joint problems: Limited range of motion, joint pain, and early onset osteoarthritis are common.
  • Cardiovascular problems: Heart valve abnormalities, such as mitral valve prolapse, are possible.
  • Hearing loss: This can occur due to the accumulation of GAGs in the inner ear.
  • Corneal clouding: This can affect vision and is a common symptom.
  • Other symptoms: These can include enlarged liver and spleen, developmental delays, and intellectual disability.

Causes

Morquio B Syndrome is a genetic disorder, meaning it is caused by changes in the genes. These changes, or mutations, are inherited from the parents. Specifically, Morquio B Syndrome is caused by a mutation in the GALNS gene.

Inheritance/recurrence risk

Morquio B Syndrome is an autosomal recessive disorder. This means that both parents must carry a copy of the mutated gene for their child to inherit the condition. If both parents are carriers, there is a 25% chance with each pregnancy that their child will have Morquio B Syndrome. It is important to note that even if a child does not inherit the condition, they have a 50% chance of being a carrier.


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Disclaimer: The information provided here is not exhaustive by any means. Always consult your doctor or other qualified healthcare provider with any questions you may have regarding a medical condition, procedure, or treatment, whether it is a prescription medication, over-the-counter drug, vitamin, supplement, or herbal alternative.