Skeletal dysplasias are malformations of bone or cartilage tissue. Hereditary mutations underlie many skeletal dysplasias. Causative treatment is not yet available for genetic osteochondrodysplasias.
What are skeletal dysplasias?
Dysplasias are malformations. Medicine distinguishes between different forms. Congenital forms, for example, are distinguished from acquired dysplasias. All dysplasias are classified as pathological phenomena and result in a visible malformation of tissues, organs, or the entire organism. A visible malformation may correspond, for example, to a body-proportional shift. Such shifts in body proportions are grouped under the collective term of skeletal dysplasia or osteochondrodysplasia. These types of dysplasia correspond to different developmental disorders of the bones or cartilaginous tissue. Different forms of skeletal dysplasia are distinguished. Depending on the exact localization of a skeletal malformation, medicine distinguishes, for example, epiphyseal, metaphyseal and spondyloid forms. In addition, lethal forms of skeletal dysplasia are treated as a separate subgroup. In addition, symptomatic causative subdivisions exist. This results, for example, in subgroups such as skeletal dysplasias with increased or decreased bone density.
Causes
The cause of skeletal dysplasia can vary in nature. In many cases, skeletal dysplasias occur as part of a congenital syndrome. In the narrow definition, osteochondrodysplasias have their cause in genes. Mutations of various DNA segments can cause body elements involved in bone or cartilage formation to become non-functional or insufficiently functional. Such phenomena are in many cases hereditary, but can also occur sporadically due to exogenous factors and are then referred to as new mutations. This mainly refers to genetic defects with defective differentiation, growth or formation processes of cartilage and bones as the cause of skeletal dysplasia. Distinctions are made between growth and developmental defects of the long bones or spine with early or late manifestation, bone density abnormalities, structural defects or metaphyseal modeling defects, and anarchic cartilage or fibrous tissue formation defects. Depending on the cause, exostoses, enchondromatoses, fibromatoses, osteopetroses, melorheostoses, and many other subtypes result in detail.
Symptoms, complaints, and signs
The symptoms of osteochondrodysplasia show a wide range of variation. For example, the skeletal changes may relate exclusively to body size. However, the physique or its proportion may just as well be characterized by the changes in anomalies. Basically, the symptoms for individual skeletal dysplasias can therefore hardly be generalized. For all dysplasias of the skeleton, the only thing that is ultimately true is that the physical development of those affected does not correspond to the conventional picture. Common symptoms of skeletal dysplasia are, for example, shortened arms or legs. The severity depends on the exact disease in each individual case. Just as often, a deformed spine may be symptomatic of skeletal dysplasia. Abnormal facial and skull shapes are also symptoms of various skeletal dysplasias, such as micrognathia. Apart from that, deformities of individual limbs may be a symptom of osteochondrodysplasia. The same is true for high bone fragility, as characterized for example by brittle bone disease. Particularly in the context of hereditary syndromes, skeletal dysplasias are often associated with other malformation symptoms, including mental retardation.
Diagnosis and course of the disease
The diagnosis of skeletal dysplasia is made clinically as well as radiologically. The physician usually develops an initial suspicion of a particular skeletal dysplasia by visual diagnosis, often immediately after birth in the case of congenital dysplasias. Some skeletal dysplasias can be detected prenatally by fine ultrasound. The diagnosis of dysplasia is confirmed by laboratory tests, which allow a differential diagnosis to bone diseases caused by metabolic changes. In the case of mutation-related skeletal dysplasias, molecular genetic examinations in the sense of chromosome structure analysis can often provide evidence of a specific mutation.This evidence is considered diagnostic and excludes, for example, dysostoses or metabolic disorders as the cause. The prognosis for patients with skeletal dysplasia depends primarily on the degree of dysplasia, the affected body regions, and organic involvement.
Complications
Malformations of the limbs or of the entire body structure are typical of all dysplasias of the skeleton. Complications arise when the particular dysplasia leads to limitations in mobility or secondary diseases of the joints and bones occur. Thus, as a result of skeletal dysplasia, joint wear, cramps and fractures often occur. Due to the deformed or shortened limbs, circulatory disorders may develop. In individual cases, this leads to blood clots, which always represent a medical emergency. The conspicuous physical appearance usually also places a psychological burden on those affected. Many sufferers develop inferiority complexes and social phobias in early childhood or adolescence. Suicidality is also increased in people with pronounced skeletal dysplasia. Treatment of the condition often results in minor and major complications. Surgical intervention is always associated with risks and occasionally causes infections or nerve injuries. The immobility of many sufferers also means that the wound is slow to heal and there are always wound healing problems and inflammations. If gene therapy is carried out, this can result in a serious disturbance of the immune system. If severe, the therapy causes cancer.
When should you see a doctor?
In skeletal dysplasia, the affected person usually always needs treatment by a doctor. There can be no self-healing in this disease. Since skeletal dysplasia is a hereditary disease, genetic counseling should also be performed if the patient wishes to have children in order to prevent the disease from being passed on to future generations. A doctor should be consulted if the affected person suffers from severe pain in the bones or a very unusual bone structure. This results in deformities or malpositions of the skeleton, with the affected person’s spine in particular being significantly deformed due to skeletal dysplasia. In many cases, the disease also leads to restrictions in movement. Therefore, if these complaints occur, an orthopedist must be consulted for skeletal dysplasia. In children, it is mainly the parents who must recognize the symptoms of the disease and consult a doctor with their child. In most cases, the complaints can be well alleviated.
Treatment and therapy
Because skeletal dysplasias in the narrow definition include only genetic diseases of the skeleton, no causative treatment exists for patients with skeletal dysplasia to date. For this reason, osteochondrodysplasias are not curable to date. Gene therapy has made substantial progress in recent years. However, gene therapy approaches have not yet reached the clinical phase. Under certain circumstances, gene therapy will open up first approaches for causal treatment of skeletal dysplasias after approval in the coming decades. So far, however, patients with osteochondrodysplasia are treated exclusively by symptomatic and supportive therapies. Thus, the treatment depends essentially on the symptoms in the individual case. As a rule, orthopedic treatment is indicated to correct deformities, lengths and axial deviations as far as possible. However, orthopedic correction is not possible in the context of all skeletal dysplasias. Bone density disorders, for example, cannot be corrected even by orthopedics. The situation is different for anarchic bone changes. Patients with such dysplasias can have foci surgically removed, for example. In the case of lethal skeletal dysplasias, the focus is again on supportive therapy. Patients with lethal diseases should primarily be relieved of pain. In addition, care by a psychologist can help the affected person and his or her relatives cope with the situation.
Prevention
Many skeletal dysplasias are now relatively well studied and can be diagnosed with near certainty by molecular genetic analysis.Since most skeletal dysplasias have a hereditary basis, genetic counseling during the family planning phase can be a preventive approach. Through genetic analysis, couples can have their personal risk of having a child with different skeletal dysplasias assessed. If the findings are appropriate, the decision may be made not to have a child of their own.
Follow-up
In most cases, the affected person has only very limited options for direct aftercare in the case of skeletal dysplasia. For this reason, the affected person should ideally see a doctor at an early stage to prevent the occurrence of other complications and discomforts, as this may also not result in independent healing. A doctor should be consulted already at the first symptoms and signs of skeletal dysplasia. Since this is a genetic disease, it cannot be completely cured. Therefore, those affected should have a genetic examination if they wish to have children, in order to prevent the occurrence of other complications and complaints. Many of those affected are dependent on regular check-ups and examinations by a doctor in order to control the symptoms on a regular basis. The support of the family is also very important, as this can also prevent depression and other psychological upsets. It can also be useful to get in touch with other people affected by skeletal dysplasia, as this can lead to an exchange of information. It may be that the patient’s life expectancy is limited by this disease.
What you can do yourself
The options for self-help are very limited in the case of skeletal dysplasia. The deformities need to be taken care of and treated by a doctor, as alternative healing methods do not bring any improvement in the structure of the skeletal system. The affected person can focus on promoting and supporting his or her mental health as well as working closely with the treating physician or therapist. Physical improvements are only possible within a limited framework. Physiotherapeutic treatment is normally provided to optimize movement patterns. The training and exercise units learned there can also be used independently in everyday life. This procedure improves mobility and can contribute to an increase in well-being. Nevertheless, the patient lives with visual blemishes as well as restrictions of movement possibilities. In order to prevent the development of a mental illness, the strengthening of self-confidence is essential. The social environment should be sufficiently informed about the existing health disorder so that unpleasant situations in everyday contact are reduced to a minimum. Sports activities or other physical movements in everyday life should be adapted to the possibilities of the organism. If necessary, relatives or friends should be asked for help in accomplishing certain tasks. Situations of overexertion or excessive physical strain should be avoided. These may lead to an increase in symptoms or further irreversible damage.
