Morquio syndrome

Definition:

Morquio syndrome is an inherited disease belonging to the group of mucopolysaccharide storage diseases. Two forms are recognized and called either A or B.

Type A disease is characterized by the absence of the enzyme galactosamine-6-sulfatase, and the excretion of keratan sulfate in the urine. Type B disease results from deficiency of beta galactosidase enzyme.

In both types there is accumulation in the body and brain of abnormally large amounts of a substance called mucopolysaccharide.

Alternative Names:
Mucopolysaccharidosis type IVA = galactosamine-6-sulfatase deficiency; Mucopolysaccharidosis type IVB = beta galactosidase deficiency

Causes, incidence, and risk factors:

Morquio syndrome is transmitted as an autosomal recessive trait. It has several symptoms in common with other mucopolysaccharide storage diseases such as coarse facial features, short stature, and skeletal and joint abnormalities.

Like Sanfilippo syndrome, onset of symptoms is delayed until after the first year, and life expectancy may exceed 20 years. Unlike Sanfilippo syndrome, the mental development is often normal.

Symptoms:
  • Family history of Morquio syndrome
  • Coarse facial features (more mild than either Hunter or Hurler syndrome)
  • Large head (macrocephaly)
  • Knock-knees
  • Widely spaced teeth
  • Bell-shaped chest with ribs flared out at the bottom
  • Short stature with a particularly short trunk
  • Hypermobile joints
  • Abnormal development of many bones including the spine
  • Compression of the spinal cord can lead to weakness or paralysis
Signs and tests:

Physical examination and testing shows:

Tests
Treatment:

There is no specific treatment for Morquio syndrome. Symptoms are treated as they occur. Patients with Morquio syndrome should have MRI of the lower skull and upper neck to determine if the upper vertebrae are underdeveloped. If they are a spinal fusion may prevent irreversible spinal cord injury.

Bone marrow transplantation or enzyme replacement therapy may be available in the future.

Support Groups:
National MPS Society, Inc. 610-942-0100, http://www.mpssociety.orgwww.mpssociety.org
Expectations (prognosis):
Bony abnormalities represent a significant problem, and correction through surgery should be made where possible. For example, small vertebrae at the top of the neck can cause slippage that damages the spinal cord so that paralysis may result. Death may occur as a result of cardiac complications.
Complications:
  • Heart failure
  • Difficulty with vision
  • Walking problems related to abnormal curvature of the spine
  • Abnormal neck bones can cause spinal cord damage that can cause severe disease including paralysis if not caught early; spinal fusion can prevent this
  • Breathing problems
Calling your health care provider:
Call your health care provider if symptoms of Morquio syndrome occur.
Prevention:
Genetic counseling is recommended for prospective parents with a family history of Morquio syndrome.

Review Date: 10/23/2001
Reviewed By: David G. Brooks, M.D., Ph.D., Division of Medical Genetics, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2003 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.