MedGen

Pseudarthrosis, or "false joint" of the tibia is the result of a developmental failure in the tibia progressing to spontaneous fracture and subsequent fibrous nonunion. The fracture is rarely present at birth but commonly develops during the first 18 months of life. [from HPO]

Neurofibromatosis 1 (NF1) is a multisystem disorder characterized by multiple café au lait macules, intertriginous freckling, multiple cutaneous neurofibromas, and learning disability or behavior problems. About half of people with NF1 have plexiform neurofibromas, but most are internal and not suspected clinically. Plexiform neurofibromas can cause pain, neurologic deficits, and abnormalities of involved or adjacent structures. Less common but potentially more serious manifestations include optic nerve and other central nervous system gliomas, malignant peripheral nerve sheath tumors, scoliosis, tibial dysplasia, vasculopathy, and gastrointestinal, endocrine, or pulmonary disease. [from GeneReviews]