Morquio Syndrome

Facts about Morquio Syndrome

Morquio Syndrome is a rare disease that is genetic in nature. It occurs when the body does not produce the chemical which breaks down long chains of sugar molecules, called glycosaminoglycans (previously known as mucopolysaccharides) Morquio Syndrome is one syndrome in a group of different syndromes or diseases known as mucopolysaccharidoses (MPS). It is specifically known as MPS IV.

In order to get this disease both of your parents must have the defective gene. One in every 200,000 babies is born with the disease, and it first presents itself between the ages of one and three. There are two types of Morquio Syndrome--in Type A, people do not have an enzyme called galactosamine-6-sulfatase. In Type B, people do not have enough of the enzyme, betagalactosidase. The long-chain sugar molecules which cannot be broken down are known as the keratan sulfate sugar chain.

The problem which occurs when these enzymes are not present in sufficient numbers is that glycosaminoglycans build up in body’s organs, including the brain, and these can cause major damage. Morquio Syndrome can cause abnormal development in the spine and other bones, a large head, knock-knees, a bell-shaped chest, shortness, abrasive facial features and teeth that are too far apart.

There is no one treatment for Morquio Syndrome. Rather, each of the symptoms are treated as they appear. Spinal surgery is often needed. Sometimes neck bones are inadequately developed and a spinal fusion is performed to prevent spinal cord damage. There are continually on-going clinical trials by drug companies and the government to try and find new treatments for this highly disabling disease 

There are many different types of tests done to confirm a diagnosis of Morquio Syndrome. These can include x-rays, eye and hearing tests, blood cultures, genetic tests, and an echocardiogram. Because of the seriousness of the disease, the tests may reveal many different complications. While brain function and cognitive ability are usually normal, cardiac problems can lead to death, and small neck bones can slip, causing spinal cord injury and paralysis. Other complications can include respiratory problems or vision and walking difficulties.

Other diseases in the mucopolysaccharidoses (MPS) family of diseases include Hurler Syndrome (MPS I H), Hunter Syndrome (MPS II), Sanfilippo Syndrome (MPS III), and Scheie Syndrome (MPS I S). Each of these has its own set of symptoms but they generally all cause bone and/or spinal problems, physical deformities, heart problems, abnormal facial features and varying levels of mental development.

Hurler Syndrome presents itself between the ages of three and eight. These children appear totally normal at birth. Symptoms of Hurler Syndrome include spinal abnormalities, stunted growth, a claw hand, heart valve problems, joint disease, deafness, eye problems, irregular facial features and mental retardation.

Hunter Syndrome has both a juvenile form and a later-onset form. Juveniles have hyperactivity, severe mental retardation, aggressive behavior and spasticity. The later version has no mental deficiency or a mild one. Both forms have the following symptoms: deafness, large head, joint problems, coarse facial features, increased hair and carpal tunnel syndrome.

Sanfilippo Syndrome can be diagnosed at around one year of age. Its symptoms include worsening mental retardation, joint and walking problems, coarse facial features with full lips, heavy eyebrows that meet, diarrhea, and sleeping difficulties.

Scheie Syndrome is the final disease in this family of genetic syndromes. Children with Scheie Syndrome do not develop symptoms until they are four to five years old. These include claw hands and deformed feet, increased body hair, stiffness in joints, abnormal facial features, and a loss of vision, which eventually will result in blindness.