Morquio disease

Description, Causes and Risk Factors:

Alternative Name: Morquio syndrome, Brailsford-Morquio disease, Morquio-Ullrich disease, type IVA, B mucopolysaccharidosis, Galactosamine-6-sulfatase deficiency, mucopolysaccharidosis type IVB, Beta galactosidase deficiency, MPS IV.

Morquio syndrome is an inherited disease of metabolism in which the body is missing or does not have enough of a substance needed to break down long chains of sugar molecules called glycosaminoglycans (formerly called mucopolysaccharides). The syndrome belongs to a group of diseases called mucopolysaccharidoses (MPS). Specifically, it is known as MPS IV.

Morquio syndrome is an autosomal recessive trait. That means both your parents must pass you the defective gene in order for you to get this disease.

There are two forms of Morquio syndrome: Type A and Type B.

Morquio syndrome Types A: Persons with Type A do not have a substance (enzyme) called galactosamine-6-sulfatase.

• Morquio syndrome Types B: Persons with Type B do not produce enough of an enzyme called beta-galactosidase.

A genetic defect has been identified in the N-acetyl-galactosamine-6-sulfate sulfatase (GALNS gene) in Morquio's syndrome type IVA or beta-galactosidase (GLB1 gene) in Morquio's syndrome type IVB. The catabolism of chondroitin 6-sulfate is also affected by the GALNS gene defect.

The body needs these enzymes to break down a long strand of sugar molecules called the keratan sulfate sugar chain. In both types, abnormally large amounts of glycosaminoglycans build up in the body and brain, which can damage organs.

The syndrome is estimated to occur in 1 of every 200,000 births. Symptoms usually start between ages 1 and 3. A family history of the syndrome raises one's risk for the condition.

Symptoms:

Coarse facial features.

• Macrocephaly (large head).

• 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 bones, including the spine.

Diagnosis:

The doctor will perform a physical examination. Examination and testing may reveal:

Abnormal curvature of the spine (kyphoscoliosis).

• Cloudy cornea.

• Heart murmur (aortic regurgitation).

• Inguinal hernia.

• Liver enlargement.

• Loss of nerve function below the neck.

• Short stature (especially short trunk).

Urine Tests: Urine tests are usually done first. These tests may show extra mucopolysaccharides, but they can't determine the specific form of MPS.

Other tests may include:

Blood culture.

• Echocardiogram.

• Genetic testing.

• Hearing test.

• Slit-lamp eye exam.

• Skin fibroblast culture.

• X-rays of the long bones, ribs, and spine.

Treatment:

There is no specific treatment for Morquio syndrome. Treatment for Morquio syndrome is focused on managing symptoms and identifying complications quickly so that they can be treated. Patients can consult several different doctors for assistance with managing the condition, and various treatment options including prophylactic steps such as spinal fusion are available. When selecting a doctor to manage treatment, it is advisable to find one who has experience working with patients who have this condition.

NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.

Reference and Source are from:

DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.