NIH

Zebra of the Week: Osteopetrosis

May 19, 2025

Osteopetrosis refers to a group of rare, inherited skeletal disorders characterized by increased bone density and abnormal bone growth. Symptoms and severity can vary greatly, ranging from neonatal onset with serious complications (such as bone marrow failure) to the incidental finding of osteopetrosis on X-ray. Depending on severity and age of onset, features may include fractures, short stature, compressive neuropathies, hypocalcemia with attendant tetanic seizures, and pancytopenia.

In rare cases, there may be neurological impairment or involvement of other body systems. Osteopetrosis may be caused by genetic changes in at least 10 genes. Inheritance can be autosomal recessive, autosomal dominant, or X-linked recessive with the most severe forms being autosomal recessive.

• Population estimate: Fewer than 50,000 people in the U.S. have this disease.
• Symptoms: May start to appear at any time in life.

Source:

NIH GARD. (Accessed 2025, May 16). Osteopetrosis. https://rarediseases.info.nih.gov/diseases/4155/osteopetrosis