Osteopetrosis

Excerpt

The name osteopetrosis is derived from the Greek language. ‘Osteo’ means bone, and ‘petrosis,’ meaning stone. Therefore, the disease is often referred to colloquially as “marble bone disease.” The disease was originally described by a radiologist in Germany, Dr. Albers-Schonberg, in 1904. Bone with abnormally increased density is the key radiographic finding. This increased density is secondary to osteoclast dysfunction and leads to the affected bones being abnormally brittle.

The name osteopetrosis encompasses a group of hereditary metabolic bone diseases, all of which detrimentally affect bone growth and remodeling leading to generalized osteosclerosis and the potential of pathologic fractures, pancytopenia, and even cranial neuropathies and hepatosplenomegaly in severe cases.

Four disease forms are known. The malignant autosomal recessive form, not named malignant due to any relation to oncology but rather due to the degree of condition severity, is very severe and often leads to mortality in early childhood. The intermediate autosomal recessive form usually becomes clinically significant during the first decade of life. These patients will often suffer pathologic fractures and progressive cranial nerve compression neuropathies but typically live into adulthood. There are two subclassifications of autosomal dominant osteopetrosis, and these patients are often asymptomatic into adulthood. Type I typically does not have increased fracture risk and presents with isolated osteosclerotic thickening of the cranial vault. Patients with type II often present in adulthood with anemia, pathologic fracture, or early arthritis.