Osteopetrosis (or marble disease) is a severe congenital disease of the skeleton, which is characterized by excessive ossification (generalized or local). In most known cases, the pathology is inherited. Very rarely, the disease is found in a healthy family.
Pathology was first studied and described by the German doctor Albers-Schoenberg in 1904. Marble osteopetrosis is also known in the literature as congenital systemic osteosclerosis. In children, the diagnosis is made almost immediately after birth. The disease is severe, fatal cases are not uncommon. In a milder course, osteopetrosis is determined only in adulthood and is usually an accidental finding during radiography due to a bone fracture.
Causes of occurrence
For many years, scientists can not come to a consensus on the etiology of Alberts-Schoenberg disease. It is believed that pathological processes are launched in the body that interfere with the normal absorption of calcium and phosphorus. Serious disturbances in the metabolism of minerals lead to the appearance of a disease called osteopetrosis. What is it and why the mechanism of destruction of bone tissue is activated , it is not possible to find out.
In most cases, it is possible to trace the unambiguous hereditary nature of the disease. Osteopetrosis (“deadly marble”) can be transmitted both in an autosomal dominant and an autosomal recessive way. In the first case, the pathology is detected already in adulthood and passes relatively easily. In recessive transmission of the symptom, Alberts-Schoenberg disease is diagnosed immediately after birth and proceeds with a large number of complications.
How does the pathology develop?
The pathogenesis of osteopetrosis is not well understood. It is assumed that the normal interaction of bone and hematopoietic tissue is still disturbed in utero. Osteoclasts - the cells responsible for the destruction of the skeleton - do not fulfill their function. As a result, the structure of the bones changes, they deform and cease to cope with their task. In addition, the blood supply and skeleton innervation are significantly impaired. Most often, long tubular bones, bones of the skull, pelvis and spine are affected.
Classification of Osteopetrosis
- Autosomal recessive form (develops from birth, proceeds with severe complications and frequent death).
- Autosomal dominant form (detected in adulthood, has a benign course).
Osteopetrosis - what is it? Symptoms of the disease
In a recessive mode of transmission, the first signs of pathology appear immediately after birth. Boys and girls get sick equally often. The child's face has a characteristic appearance: wide cheekbones, eyes set far apart. The root of the nose is always depressed, the nostrils are turned outward, and the lips are thick. Soon progressive anemia and hydrocephalus develops, a marked increase in the liver and spleen occurs. Hemorrhagic diathesis is very common. The inevitable finale is multiple bone damage. When the process spreads to the cranium, compression of the optic and auditory nerves occurs, blindness and deafness develop.
Osteopetrosis is a deadly process affecting almost all long tubular bones. Most children do not even live to be 10 years old. Purulent osteomyelitis of bone tissue develops, leading to disability. The cause of death, as a rule, is severe anemia and sepsis.
In the dominant version, the pathology is detected in children of school age, as well as in adults. As a rule, the patient does not even suspect that such an insidious disease has settled in his body. Osteopetrosis is usually an accidental finding during radiography for a bone fracture. In many cases, the pathology is completely asymptomatic. Some patients complain of periodic bone pain, others become frequent clients of traumatologists, now and then getting on the operating table with pathological fractures. Anemia, as a rule, is slightly expressed, neurological disorders as a result of compression of nerve fibers are rare.
In mild forms of Alberts-Schoenberg disease, mental abnormalities in development are not noticed. Very characteristic of this pathology is late teething, their improper development, a tendency to tooth decay. Low growth at birth is not peculiar, lag in physical development is detected closer to the year.
Osteopetrosis (deadly marble). Diagnostics
In the case of early development of pathology, a small patient falls into the hands of doctors in the first months of life. In this case, the diagnosis is usually not particularly difficult. The characteristic appearance of the patient makes it possible to suspect osteopetrosis. At an older age, patients are usually already registered with an orthopedic surgeon due to frequent fractures. In adults, the clinical picture is blurred, many signs do not appear, which makes diagnosis difficult.
In all cases, regardless of age, an X-ray examination can confirm or refute osteopetrosis. What is this and what is the meaning of the method? In a specially equipped office, a picture of the affected area is taken in two projections. On radiographs, bone compaction is clearly visible, while the border between the tubular and spongy substances is absent. The bones are deformed, metaphyses (areas near the joints) are significantly expanded. Typically, the spine, skull, and pelvis are involved. The wave-like course of the disease provides a transverse striation of the vertebrae and long tubular bones, which is clearly visible in the x-ray.
Osteopetrosis treatment
Radical healing from this serious illness has not been developed. The treatment is mainly symptomatic, aimed at improving the general condition and improving the quality of life. If Albers-Schoenberg disease is detected at an early age, a bone marrow transplant can be performed on the patient. This is a relatively new procedure that allows you to save the life of a child even in the event of severe skeletal lesions. The sooner a bone marrow transplant is performed, the greater the chances of a successful outcome of the disease.
For the operation, it is required to obtain material from a close relative, with whom the patient will show maximum compatibility with HLA genes. Otherwise, the bone marrow does not take root, serious complications arise that threaten the patient's life. To determine the compatibility, special blood tests are performed to determine the similarity of the donor and recipient genomes.
With a successful outcome of the operation, the bone structure is gradually restored. There is an improvement in the general condition, normal vision and hearing. Transplantation is the only chance for those patients for whom other treatment methods have not brought any visible results.
Bone marrow stem cell transplantation is also a very promising area for healing from a disease such as osteopetrosis. What it is? In this case, not a whole organ is transplanted, but only individual cells. They take root in the patient’s bone marrow and restore normal blood formation. This procedure is much easier to tolerate in small patients, since it does not require intravenous anesthesia.
For the treatment of adults, calcitriol or γ-interferon is used, which normalize the activity of osteoclasts, thereby inhibiting the destruction and compaction of bone tissue. Such therapy can significantly reduce the risk of new fractures, which favorably affects the patient's quality of life.
Complications of Osteopetrosis
Frequent fractures of long tubular bones are a problem that sooner or later every patient faces. The thigh is most affected, damage to the lower jaw, spine, and chest is not ruled out. Against the background of impaired hematopoiesis, purulent osteomyelitis develops, which is difficult to treat. Pronounced deformities of the extremities are the inevitable result of a serious illness called osteopetrosis. Photos of the consequences of this pathology look quite scary.
Forecast
The course of the disease largely depends on the age of the patient. In some cases, the development of pathology may suddenly stop and do not remind of itself for many years. In other embodiments, the disease progresses with severe anemia and frequent purulent infections. The younger the child, the greater the likelihood of serious complications and death. And, on the contrary, in adulthood, the disease manifests itself much less actively, annoying only the increased fragility of the bones of the skeleton.
Regardless of the severity of the disease, all patients with a confirmed diagnosis should be followed up by an orthopedist for life. An experienced doctor will be able to timely identify any complications that arise and, if necessary, to prescribe additional methods of examination and treatment.