In melorheostosis, the bones of the extremities thicken in whole or in part without the patient noticing. Muscular edema, growth disorders or restricted movement are only seen in rare cases. Symptomatic therapy is limited to patients with actual symptoms.

What is melorheostosis?

Diseases with specified changes in bone density or bone structure are a diverse group that includes many individual diseases and can show a wide variety of clinical manifestations. One such manifestation is melorheostosis. The condition is also known as Léri syndrome and was first described in the 20th century. See AbbreviationFinder for abbreviations related to Melorheostosis.

The Parisian neurologist André Léri is considered the first to describe it, in whose honor the term Léri syndrome was introduced. Melorheostosis manifests itself in thickening of the skeleton, which is mostly in the extremities. The syndrome is sometimes referred to as mesenchymal dysplasia and is thus associated with anomalies in the embryonic mesenchymal tissue.

The manifestation can take place at any age. With a prevalence of less than 1 case in 1,000,000 people, melorheostosis is an extremely rare disease. The clinical terms candle wax disease and waxy bone disease are often used interchangeably with melorheostosis and describe the structural bone changes pictorially.

Causes

Waxy bone disease is believed to be sporadic. Familial clusters have not been observed to date. An inheritance could therefore not be identified so far and is not considered applicable on the basis of the previous cases. Nevertheless, the disease seems to be based on genetic factors that lead to structural changes and functional impairments in the bone tissue.

Bone changes have only recently been linked to a specific gene. Medicine currently suspects a mutation in the LEMD3/MAN1 gene to be the cause of the disease. This gene takes over the coding for protein elements of the inner nuclear membrane in the DNA. This is the inner part of the double-layered membrane that encloses the interior of cell nuclei and controls the transport of substances between the plasma and cytoplasm.

The mutation of the mentioned gene reduces the function of the nuclear membranes and thus impedes the exchange of substances between the nucleus and the cytoplasm. The factors that cause the mutation have not yet been clarified. For example, exposure to toxins or malnutrition during pregnancy are possible.

Symptoms, Ailments & Signs

Although it is a congenital condition, most patients with melorheostosis do not show any symptoms until late adulthood. They often remain asymptomatic for the rest of their lives and receive their diagnosis from an incidental finding. In other cases, the symptom complex manifests itself early on through dermal changes.

For example, fibrosis of the dermal tissue can develop on the skin over the changed bone structures. In addition, some patients show edema of the muscles over the affected bone regions, which is accompanied by thickening and impairment of the muscles, tendons or joints. Joints affected in this way in particular sometimes also cause pain or involuntary contractures of the muscles.

Patients with melorheostosis show growth disorders somewhat less frequently because the changes in the bones bridge the growth plates, for example. All changes in melorheostosis occur preferentially on the limbs. Only in absolutely exceptional cases do dermal and skeletal symptoms of the disease manifest themselves at other locations. Some patients also notice differences in length or deformation of the extremities as symptoms.

Diagnosis & disease progression

Since melorheostosis usually remains asymptomatic, she rarely takes her patients to the doctor. In most cases, the disease is recognized as an incidental finding in the X-ray image, for example in the case of X-rays in the context of a broken bone or accident. X-rays show dermatomal, striated sclerotizations and densifications that are reminiscent of dripping wax.

Radiologically, the doctor must rule out diseases such as osteomyelitis, osteopetrosis, osteopoikilia or Buschke-Ollendorff syndrome and scleroderma. This exclusion can take place, for example, by means of molecular genetic analysis. If there is evidence of mutations in the LEMD3/MAN1 gene, the diagnosis of melorheostosis is considered secure.

Complications

Melorheostosis does not always lead to symptoms or complications. In many cases, melorheostosis does not cause any symptoms, so people live with the disease throughout their lives. Even with an accidental diagnosis, treatment does not always have to be initiated if those affected do not complain of any symptoms.

Melorheostosis can also cause distortions in the skin or bones. This negatively affects the muscles and joints in particular, which can lead to disturbances in the patient’s movement. This also significantly restricts everyday life. In children, melorheostosis can lead to growth disorders and thus to developmental disorders.

This often leads to deformations of the extremities or to different lengths of the extremities. However, the patient’s life expectancy is not reduced by this disease. The symptoms of melorheostosis can be limited by various therapies and therapeutic measures.

In some cases, however, those affected have to live with the restricted mobility their entire lives. It is generally not possible to predict whether the course of the disease will be positive.

When should you go to the doctor?

Many patients with melorheostosis do not develop symptoms until late adulthood. Since the disease is characterized by being symptom-free over a long period of time, there are no signs or warning signals for those affected that make a doctor’s visit necessary. If the congenital disease shows the first limitations in motor skills, a doctor is needed. If the affected person suffers from loss of muscle strength, internal weakness or swelling near the bones, a doctor should be consulted. There is cause for concern if the arms and legs can no longer be stretched or bent as usual.

In the case of general movement restrictions or irregularities in the movement sequences, a doctor must be informed of the observations. If there is pain in the bones, joints or tendons, the cause should be clarified. The development of edema or disturbances in the voluntary contraction of the muscles should be examined and treated.

If the general risk of accidents and injuries increases due to the symptoms, everyday life should be restructured. A treatment plan is drawn up together with a doctor. In addition, the person concerned receives important information on preventive care and necessary measures when they visit a doctor. Deformations of the bones, abnormalities of the skeletal system and differences in length of the extremities must be examined by a doctor.

Treatment & Therapy

No causal therapy methods are currently available for patients with melorheostosis. The disease is currently considered incurable. Although gene therapy approaches are currently being researched as causal therapy steps for genetic diseases, they have not yet reached the clinical phase. Genetic diseases such as melorheostosis can therefore only be treated symptomatically at the present time.

With melorheostosis, the question arises as to the usefulness of such therapy. Since most patients remain asymptomatic until the end of their lives, no treatment is necessary in most cases. However, if symptoms are present, there are various treatment options available. Movement restrictions and growth disorders, for example, are often treated with the use of contractures and bone braces.

The dermal symptoms and fibrosis of the skin do not necessarily have to be treated. In most cases, they do not further affect the patient and almost never develop into serious phenomena. As long as the proliferation of connective tissue does not bother the patient, no therapy is usually applied. Symptoms such as edema of the muscles, on the other hand, should be treated very well. This treatment is always drug therapy and can, for example, correspond to the administration of diuretics.

Outlook & Forecast

The disease melorheostosis is currently considered incurable. Genetic causes probably cause the malformation of the bones. In most cases, there is still a positive prognosis for those affected. You will remain symptom-free for the rest of your life. The problems turn out to be minor. Some scientists are of the opinion that the typical signs rarely appear after the age of 20. As a result, developing boys and girls are considered a risk group.

If symptoms occur, they can usually be successfully remedied by physiotherapy or surgery. Doctors only perform an amputation in exceptional cases. Melorheostosis does not shorten life expectancy. However, patients may have to be able to cope with slight or severe movement restrictions. As a result, professional and private goals cannot always be fully realized. Mental stress can occur.

If there is no therapy, there are usually no disadvantages. This is due to the fact that the majority of those affected notice little or no symptoms. However, if complications occur, medical treatment is indicated. Refusing such offers of help can encourage immobility.

Prevention

So far, the triggering factors for a mutation in the LEMD3/MAN1 gene are not known: even the mutation itself has only recently been linked to the disease. As long as the causative factors are not known, melorheostosis cannot be prevented.

Aftercare

Since melorheostosis has so far been considered incurable, follow-up care focuses on stabilizing quality of life. Sometimes those affected remain symptom-free for the rest of their lives. The problems turn out to be minor. Some scientists are of the opinion that the typical signs rarely appear after the age of 20. As a result, developing boys and girls are considered a risk group.

In general, those affected and their families are advised to lead a healthy lifestyle with a balanced diet to support the immune system. He will also suggest certain relaxation and mental techniques for stabilization and advise as many leisure activities as possible, which should bring the affected family many happy hours together.

If the parents who have already been affected wish to have another child, a precise genetic test is recommended to determine in advance the probability of having another child with the disease.

You can do that yourself

In addition to medical therapy, those affected can alleviate the symptoms of melorheostosis with some measures and home remedies.

First of all, general tips such as taking it easy and avoiding stress apply. Since the growth disorders and movement restrictions are often associated with a low level of well-being, appropriate countermeasures should be taken. This can be a fulfilling hobby, but also a healthy diet, exercise or a chat with friends. Which strategies make sense in detail is best determined together with a therapist. In general, melorheostosis patients should always consult a psychologist who can give further tips on how to deal with the psychological complications of the bone disease.

The physical symptoms can be treated with the help of natural preparations. Pain can be relieved with natural remedies such as the anti-inflammatory devil’s claw or the soothing willow bark. Arnica and corresponding preparations from homeopathy help with stronger pain. In the case of edema, the affected area should be cooled and positioned upwards. Sometimes compression stockings also help, which should be custom-made if possible and must be worn consistently. Plant extracts from red vine leaves or horse chestnut seeds support the breakdown of water retention. Also aescrin, rutoside and ruscus root.