The patient has a history of type I autosomal dominant osteopetrosis.

Autosomal dominant osteopetrosis is the less severe type of osteopetrosis and should be considered and compared with the other subtype: autosomal recessive osteopetrosis. The autosomal dominant (AD) type is less severe than its autosomal recessive (AR) mate. Hence, it is also given the name "benign" or "adult" since patients survive into adulthood (something that is unlikely with the AR type).

Classification

• type I: pronounced osteosclerosis of cranial vault with clinical presentation as cranial nerve palsies
• type II: end plate thickening of vertebrae (sandwich vertebra) and endobones ("bone-within-bone" appearance) in pelvis, increased risk of fracture

Differential diagnosis of diffuse calvarial thickening is listed in this article:

Calvarial thickening