The osteosclerosis is a type of osteopetrosis with abnormal hardening of the bones, which leads to increased skeletal density at low disorder of skeletal formation. In some species are among the consequences cytopenias by an advance of the bone into the marrow cavity.
The osteosclerosis is a type of osteopetrosis with abnormal hardening of the bones, which leads to increased skeletal density at low disorder of skeletal formation. In some species are among the consequences cytopenias by an advance of the bone into the marrow cavity. Osteopetrosis, delayed manifestation (Albers-Schonberg syndrome) This form of osteopetrosis is autosomal dominant, benign and manifests itself later during childhood, adolescence or early adulthood. The defective CLCN7 gene encodes a chloride channel, which is apparently important for osteoclast function. This disorder is relatively common with great geographic and ethnic distribution. The affected patients are asymptomatic, general health is not affected. However, facial paralysis and numbness may occur due to entrapment of cranial nerves. Bony growths can narrow the marrow cavity, thereby causing cytopenias of anemia to pancytopenia. In case of extramedullary hematopoiesis may occur hepatosplenomegaly. As a result of hypersplenism may worsen the anemia. The skeleton is radiologically at birth without any findings. The bone sclerosis but is increasingly evident with increasing age of the children; the diagnosis is often made by chance when an x-ray for some other reason is made. The bone involvement is extensive, but irregular. The cap is tight and the sinuses are obliterated. The sclerosis of the vertebral end plates are the spine the characteristic appearance of a “gross jerseys”. Some patients may require the treatment of anemia transfusion or splenectomy. Osteopetrosis with early manifestations of this form of osteopetrosis is autosomal recessive and is malignant, congenital and manifests itself in infancy. It is rare, often fatal and is caused by a mutation in the osteoclast-associated gene TCIRG1. The bone overgrowth increasingly destroys the marrow cavity, resulting in severe pancytopenia. Early symptoms include failure to thrive and spontaneous occurrence of subcutaneous bleeding and abnormal bleeding and anemia. Paralysis of the nerves. optic, oculomotor nerve and faciales and hepatosplenomegaly occur later. A bone marrow suppression with anemia, fulminant infection and bleeding usually results in the first year of life to death. The diagnosis is suspected by the presence of bony growths associated with anemia, abnormal bleeding and growth disorder. Usually, radiographs are made, along with blood tests and coagulation tests. A generalized increased bone density is the predominant radiological feature. X-rays of the long bones are transverse bands in the Metaphysengebieten and longitudinal stripes in the shafts. Proceeds the disease, the ends of long bones, particularly the proximal humerus and the distal femur, bottle-shaped develop. Characteristic Endoknochen (bone in a bone) occur in the vertebrae, on the basin and in the tubular bones. The skull bones thicken, and the spine is similar to a “gross Jersey”. Bone marrow transplantation with an HLA-identical transplant have yielded excellent results. Poor results were however obtained with non-HLA-identical transplants. Prednisone, calcitriol and interferon-? are effective in some cases. Osteopetrosis with renal tubular acidosis This form is inherited as an autosomal recessive trait. The genetic defect involves a mutation of the carbonic anhydrase II gene. It causes weakness, stunted growth and failure to thrive. The skeleton appears radiographically dense and it can be seen cerebral calcifications. Renal tubular acidosis is present, the carbonic anhydrase in red blood cells is reduced. A bone marrow transplant cures the osteopetrosis, but has no effect on renal tubular acidosis. Long-term therapy with bicarbonate and electrolyte replacement can correct the renal losses. Pyknodysostosis This autosomal recessive disease caused by loss of function mutations caused in the gene encoding cathepsin K, an osteoclast-derived protease that is essential for the degradation of the extracellular bone matrix. In this autosomal recessive disorder, a small body size falls already in childhood. The adult size is ? 150 cm. Other symptoms include an enlarged head, short and broad hands and feet, short sclerotic Phalange, dystrophic nails and retained baby teeth. Blue sclera (due to a shortage in the connective tissue, so that the vessels underlying shine through) are usually detected during childhood. Sufferers are very similar. They have narrow faces, a receding chin and decayed, missing Asked teeth. The head skull shows bump-like projections and the anterior fontanelle remains open. Pathological fractures are a major complication. The diagnosis is suspected by the presence of blue sclera, short stature and characteristic skeletal features. Typically, an X-ray is performed. Bone sclerosis appear on X-rays during childhood, but neither Knochenstreifungen or inner bone formations (Endoknochen) can be seen. The facial bones and paranasal sinuses are hypoplastic and the mandibular angle is obtuse. The distal phalanges are rudimentary. The clavicles can be graceful, with underdevelopment of the lateral parts. With the help of plastic surgery severe deformities of the face and jaws can be corrected.