Morquio’s disease is a very rare metabolic disorder caused by an enzyme defect. In the context of this disease, the breakdown of glycosaminoglycans is disrupted, causing damage to the affected tissue.
What is Morquio’s disease?
Morbus Morquio was first described in 1929 by the pediatrician Luis Morquio. It is a congenital metabolic disease caused by a defective protein. Depending on the defect, a distinction can be made between Morbus Morquio type A and Morbus Morquio type B. See growtheology for Comprehensive Guide to Blow-out Fracture.
Morquio’s disease is an inherited disease, with the mode of inheritance being autosomal recessive. If the mother and father carry a faulty gene, this gene can be passed on to the child. As a result, the corresponding enzyme is not produced in the body and the child subsequently develops Morquio’s disease. Depending on the enzyme defect, a distinction is made between Morquio type A and Morquio type B.
In Morquio type A disease, there is a defect in a 6-sulfatase. As a result, the body’s own glycosaminoglycans cannot be completely broken down and cleavage products are produced which are stored in lysosomes. In some cases, there is also an increased excretion of these intermediate products, such as keratan sulfate in Morquio type A disease or chondroitin-6 sulfate in Morquio type B disease.
In addition, the breakdown products are stored in the liver, spleen, connective tissue, eye and skeletal system, where they trigger functional disorders. They are only stored in connective tissue cells and not in the central nervous system, so that the patients have normal intelligence.
Symptoms, Ailments & Signs
The severity of Morbus Morquio disease varies, sometimes the disease is not diagnosed until adulthood due to a lack of symptoms. Typical symptoms are short stature with a very short neck, knock knees and corneal opacities. The intelligence of those affected is not reduced, nor are the liver and spleen enlarged.
Morquio’s disease patients rarely reach a height of more than 120 centimeters. The short stature is due to shortened tubular bones, which often only becomes apparent in the fourth year of life. In addition, those affected have a keel chest, their joints are hypermobile and the face is reminiscent of gargoyle figures (gargoyles), so that these changes are also referred to as gargoylism.
The chin is prominent and enlarged, the head is relatively large and the cheeks are quite pronounced. The bone changes that can be seen in the spine are also very noticeable. The vertebrae between the lumbar and thoracic spine often have the shape of a wedge, the vertebral bodies are relatively flat and the so-called deus axis (dental process of the second cervical vertebra) is not properly fixed, which can lead to spinal canal stenosis or even paraplegia.
The instability can also damage the spinal cord and neurological deficits such as sensory disturbances or paresis can occur. Furthermore, the teeth often have defects in the enamel, very often there are also hernias and umbilical hernias, which makes an operation necessary.
Diagnosis & course of disease
The diagnosis of Morquio’s disease can be made by detecting a high excretion of chondroitin sulfate or keratan sulfate. In addition, an X-ray examination of the ankles and wrists or the spine can be revealing, as this is where pronounced skeletal changes usually appear.
Furthermore, it is possible to determine the activity of the defective enzyme in the fibroblasts or leukocytes. If there is a genetic change in the family, a test can be carried out during pregnancy to determine whether the unborn child may have a disease.
Patients with Morquio’s disease suffer from various malformations in their bodies. In most cases, so-called knock knees occur, which can lead to restricted movement and thus severe restrictions in everyday life. The cornea also becomes cloudy and patients suffer from a very short neck. However, the intelligence of those affected is not affected by Morquio disease. There is also short growth.
Especially for children, this can mean bullying or depression because they feel uncomfortable with their stature. The head is also often unusually large, which can lead to inferiority complexes or reduced self-esteem. Furthermore, Morquio’s disease can lead to paralysis or sensory disturbances throughout the body, thereby significantly reducing the quality of life.
Various defects also appear on the teeth, which can complicate everyday life. Treatment of Morquio’s disease is symptomatic and aims to reduce symptoms. In this way, infections of the respiratory tract can be avoided. Those affected are also dependent on taking medication and physical therapy. With the treatment itself, there are no special complications.
When should you go to the doctor?
The enzyme defect known as “Morbus Morquio” is an extremely rare, congenital metabolic disorder that is not a common occurrence. In addition, the associated symptoms sometimes do not appear until adulthood. This often delays a visit to the doctor.
However, it is unusual that the massiveness of the symptoms in some sufferers of Morquio’s disease does not lead to symptoms. In most cases, this disease cannot be overlooked in view of the typical symptoms that occur, such as short stature in the range of 120 centimeters in height, a noticeably short neck or knock-knees. The shape of the face also indicates an accompanying gargoylism early on. Massive skeletal changes are also noted during a doctor’s visit.
The skeletal malformations associated with Morquio disease require treatment. There are also increased anesthetic risks. This makes surgical interventions that serve to correct painful misalignments or restricted mobility more difficult. Except for symptomatic treatment, doctors have not been able to do much for those affected. New enzyme replacement therapies for patients with Morquio’s disease are already being tested in some clinics.
Since the side effects of this illness often lead to inferiority complexes or bullying experiences, psychotherapeutic care should also be considered. Regular visits to the doctor or physiotherapeutic measures are unavoidable in Morbus Morquio. Visual and hearing impairments as well as immunological problems must be treated. Life expectancy can only be assumed to be 50 years with appropriate medical treatment.
Treatment & Therapy
Treatment of Morquio disease is mainly symptomatic (surgery, prostheses, spinal fusion to stabilize the neck), and enzyme replacement therapy is being tried. The provision of aids and physiotherapy treatment also play an important role. Many children who suffer from Morquio’s disease often also have hearing problems, so that a hearing aid makes sense in some cases.
Acute bacterial infections are very often treated with antibiotics. To prevent respiratory infections, it is also recommended to remove tonsils and polyps. Thorough dental care is also important, as the enamel is not very resistant. The opacity of the cornea usually does not affect vision, but those affected are often very sensitive to light, and tinted glasses can help here.
It is also important to carry out an ultrasound examination of the heart at regular intervals, since storage material is also deposited in the heart muscle. If there are problems in the skeletal system, physiotherapy is advisable, as it relieves pain and can also delay joint stiffness. The strength of the joints can also be supported with special splints.
Comprehensive neurological examinations are also important in order to be able to identify possible complications in the area of the cervical spine in good time. In Morbus Morquio patients, anesthesia should also only be carried out by a very experienced doctor, as certain precautionary measures are required. The prognosis depends on the severity of the disease and the quality of treatment. With appropriate treatment, those affected usually live to be more than 50 years old.
Outlook & Forecast
Morquio’s disease is incurable. The prognosis is based on the symptoms and the time at which therapy begins. Affected children must be provided with the necessary aids at an early stage in order to avoid further damage and improve their quality of life. Sick children can use tinted glasses, for example, to protect their sensitive eyes from the sun’s rays. With comprehensive treatment, a life expectancy of over 50 years is possible.
There is a prospect of a symptom-free life if the symptoms are treated comprehensively and no serious health complications such as respiratory infections occur. Regular ultrasound examinations of the heart can also improve the prognosis. Those affected also need therapeutic care in order to process the consequences of the disease. The sooner therapy is initiated, the better the prospects. Therefore, a doctor should be consulted at the first suspicion.
The extreme rarity of the disease can have a negative impact on the prognosis, since the condition may not be diagnosed until late. Examinations by appropriate specialists for genetic modifications are necessary in order to receive an early diagnosis and to be able to start the treatment of Morquio disease.
Because Morquio’s disease is a hereditary disease, it cannot be prevented. In the case of an existing disease, however, it is possible to ensure successful treatment with timely therapy. If there are already cases of Morquio disease in the family, genetic counseling can be used if there is a desire to have children, in order to be able to better assess the risk.
Morquio’s disease is a hereditary disease that is based on an enzyme defect. The disease is primarily treated symptomatically, since enzyme replacement therapy is currently still in the experimental stage. The therapy is therefore usually limited to aids that are intended to make everyday life more bearable for the patient. Prostheses must be precisely adjusted and replaced if necessary.
Dark-tinted glasses and sunglasses protect the sensitive eyes from strong light, hearing aids improve the often increasing hearing loss. Very thorough dental care is necessary, since in many cases tooth enamel is not sufficiently formed in Morbus Morquio. The extremely rare disease is often associated with social ostracism. Especially when they are children, patients suffer from teasing and bullying because of their deformities such as short stature, knock knees and an unnatural head size.
The empathy of parents and other contact persons is particularly important here. Psychotherapeutic help is therefore recommended for both those affected and their relatives. Relaxation techniques such as yoga can also contribute to psychological stabilization and give you new strength. Since Morquio’s disease occurs very rarely, self-help groups are rarely found. The Society for Mucopolysaccharidoses provides more information about the disease.
You can do that yourself
If the child was born with Morquio’s disease, the parents and other relatives are called upon first. Since enzyme replacement therapy is still in the experimental stage, Morquio’s disease is treated symptomatically. Great adherence to therapy is important here.
Prostheses, for example, have to be precisely adjusted and, if necessary, replaced or renewed. This also applies to other aids such as dark-tinted glasses and sunglasses to protect light-sensitive eyes, and hearing aids. Since Morquio’s disease is often associated with insufficiently formed tooth enamel, regular, thorough dental care is important.
Morquio’s disease is usually associated with short stature, knock knees and other malformations, especially on the head, which is why the affected children are often teased or even bullied. This gnaws at self-confidence and makes psychotherapeutic treatment advisable. Relatives should also seek psychotherapeutic support in order to be able to meet the demands that a child with Morquio’s disease places on them. Relaxation techniques such as yoga or Reiki bring balance and also give you strength.
Because the disease is extremely rare, there is no corresponding self-help group in this country that those affected and their relatives could join. Because Morquio’s disease is one of the mucopolysaccharidoses, the Gesellschaft für Mukopolysaccharidosen eV also provides information about Morquio’s disease (www.mps-ev.de/mps/mukopolysaccharidosen).