Osteopetrosis Clinical Presentation

Updated: Sep 11, 2017
  • Author: Robert Blank, MD, PhD; Chief Editor: George T Griffing, MD  more...
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History and Physical Examination

Infantile osteopetrosis

Infantile osteopetrosis (also called malignant osteopetrosis) is diagnosed early in life. Failure to thrive and growth retardation are symptoms.

Bony defects and associated symptoms occur, including the following:

  • Nasal stuffiness due to mastoid and paranasal sinus malformation is often the presenting feature of infantile osteopetrosis

  • Neuropathies related to cranial nerve entrapment occur due to failure of the foramina in the skull to widen completely

  • Manifestations include deafness, proptosis, and hydrocephalus.

  • Dentition may be delayed

  • Osteomyelitis of the mandible is common due to an abnormal blood supply

  • Bones are fragile and can fracture easily

  • Defective osseous tissue tends to replace bone marrow, which can cause bone marrow failure with resultant pancytopenia

  • Patients suffer from anemia, easy bruising and bleeding (due to thrombocytopenia), and recurrent infections (due to inherent defects in the immune system)

  • Extramedullary hematopoiesis may occur, with resultant hepatosplenomegaly, hypersplenism, and hemolysis

  • Other manifestations include sleep apnea and blindness due to retinal degeneration

Adult osteopetrosis

Adult osteopetrosis (also called benign osteopetrosis) is diagnosed in late adolescence or adulthood. Two distinct types have been described, type I and type II, on the basis of radiographic, biochemical, and clinical features. (See Table 3, below.) [15]

Table 3. Types of Adult Osteopetrosis (Open Table in a new window)


Type I

Type II

Skull sclerosis

Marked sclerosis mainly of the vault

Sclerosis mainly of the base


Does not show much sclerosis

Shows the rugger-jersey appearance


No endobones

Shows endobones in the pelvis

Transverse banding of metaphysis


May or may not be present

Risk of fracture



Serum acid phosphatase


Very high

Approximately one half of patients are asymptomatic, and the diagnosis is made incidentally; the diagnosis often made in late adolescence, because radiologic abnormalities start appearing only in childhood. In other patients, the diagnosis is based on family history. Still other patients might present with osteomyelitis or fractures.

Many patients have bone pains. Bony defects are common and include neuropathies due to cranial nerve entrapment (eg, with deafness, with facial palsy), carpal tunnel syndrome, and osteoarthritis. Bones are fragile and may fracture easily. Approximately 40% of patients have recurrent fractures. Osteomyelitis of the mandible occurs in 10% of patients.

Other manifestations include visual impairment due to retinal degeneration and psychomotor retardation. Bone marrow function is not compromised.

Physical examination

Physical findings are related to bony defects and include short stature, frontal bossing, a large head, nystagmus, hepatosplenomegaly, and genu valgum in infantile osteopetrosis.