Morquio syndrome is a problem that occurs when the body lacks or does not produce enough enzyme that will digest the long strands of sugar molecules. This would cause the sugar molecules to collect and harm the cells and tissues resulting in various skeletal and physical problems, hearing loss, vision problems and heart abnormalities. The syndrome is present at birth and early medical intervention can improve the quality of life of the patient.
Children with Morquio syndrome are treated based on the severity of the symptoms. A team of qualified healthcare specialists will work together in designing the best and most appropriate treatment strategy. The goal of the treatment is to help the patient deal with the odd effects of the syndrome as well as identify the potential complications and prevent them from developing.
Morquio syndrome is an inherited metabolic disorder wherein both parents pass the defective genes involved in the production of enzymes that digest long strands of sugar molecules to their offspring. The genes involved are:
- GALNS (galactosamine (N-acetyl)-6-sulfate sulfatase)
This gene is specifically involved in the production of N-acetylgalactosamine 6-sulfatase enzyme which not only digests long strands of sugar molecules but removes the sulfate molecules present in large amounts in the cornea and cartilage.
- GLB1(galactosidase beta 1)
This gene is responsible for the production of beta-galactosidase which helps break down sugar molecules. It is also involved in the production of elastin-binding protein which helps form elastic fibers in the connective tissues.
Mutations in these genes will deactivate the enzymes they produce, making them partially or completely absent. Morquio syndrome can be type A when there are mutations in GALNS gene; or type B if the mutations are found in the GLB1 gene. The syndrome is also referred to as MPS IV or Mucopolysaccharidosis type IV. This was discovered independently and simultaneously in 1929 by Uruguayan physician Luis Morquio and British radiologist James Frederick Brailsford.
Problems related to the syndrome arise when large sugar molecules remain unbroken, causing them to accumulate in many cells, tissues and organs, especially in the bones. This explains why persons afflicted with the condition have bone abnormalities. The amassing of large sugar molecules in the digestive units of cells also affects other proteins resulting in an additional set of problems. Morquio syndrome affects the bones, joints, ears, eyes, skin, spleen, liver, bone marrow and even the arteries. Some of the hallmark features of the syndrome are:
- Cloudy corneas
- Bell-shaped chest
- Broad mouth and widely-spaced teeth
- Prominent breastbone
- Stunted neck
- Curved spine
- Hypermobile joints
- Flat feet
- Prominent buttocks
- Vision problems
- Hearing loss
With the combined anomalies involving the spine, the affected individual will have some difficulties with some positions as well as in walking, resulting in a duck-like waddling gait. In addition, the heart a Morquio syndrome patient could suffer as well. Remarkably, intelligence is not affected by the condition.
Diagnosis and prognosis
Timely diagnosis and treatment can really make a big difference in improving the quality of life of the patient. It should be noted that the syndrome is not always obvious at birth unless there are significant heart anomalies or complications. In most cases, Morquio syndrome is detected sometime between the 1st and 3rd years of the child’s life when growth suddenly stops and physical and bone deformities become more pronounced.
The chances for survival highly depend on how severe the condition is. Some patients live only for 2 or 3 years after birth, while others reach childhood and adolescence. Still, others reach up to the 6th or 7th decade of their lives.
The treatment is planned based on the thorough evaluation of a team of doctors composed of a pediatrician, ophthalmologist, orthopedist and cardiologist. The pediatrician will look for the physical manifestations of the syndrome as well as organ involvement. An ophthalmologist will check for vision problems, while the orthopedist will examine for spine and bone abnormalities. The cardiologist will likewise investigate for heart anomalies. X-rays, MRI, echocardiogram and some blood work will confirm the condition.
There is no definite way to treat Morquio syndrome. However, treatment can improve the chance of survival of the patient as well as help him/her feel better. The syndrome can have detrimental effects on the social well-being of the person, making it hard for him/her to fit in with others. In addition, the associated health problems and future complications could prevent the patient from enjoying life to the fullest. But all these will be endeavored to be addressed in the treatment. Spinal fusion is usually done to correct undeveloped cervical vertebrae or neck bone. Other bone problems as well as heart defects are likewise treated accordingly.
Having a child with Morquio syndrome can be overwhelming and even frustrating. But knowing that many families are also dealing with the syndrome and coping successfully is a great source of encouragement.