Four stages are recognised in this condition. The first (latent stage) show no symptoms or signs. This stage typically lasts up to the early 20s. This is followed by the osseous stage. This is characterised by recurrent bone pain usually affecting the long bones of the limbs. This is usually followed by pathological fractures of these bones. The third stage (early neurological) is marked by the onset of symptoms typical of a frontal lobe syndrome (euphoria, lack of concentration, loss of judgment and social inhibitions) with memory loss. Epilepsy may occur. This stage usually has its onset in the late 20s and early 30s. The final stage is characterised by severe dementia and paralysis. Death usually occurs in the late 40s or early 50s.
Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy
Chronic multifocal Langerhans cell histiocytosis
Terminal osseous dysplasia with pigmentary defects
Generalized arterial calcification of infancy
Diffuse idiopathic skeletal hyperostosis
Diffuse capillary malformation with overgrowth
Fibrous hamartoma of infancy
Melanotic neuroectodermal tumor of infancy