Freiberg Disease and Avascular Necrosis of the Metatarsal Heads.

Freiberg disease is characterized as osteochondrosis of the second metatarsal head. It is the fourth most common form of primary osteochondrosis with a significant predilection to the adolescent athletic female population, although it has been seen over a wide age range. If treated early, osteochondroses such as Freiberg disease are essentially self-limiting, often resolving with nonoperative management.

Identification of familial and de novo microduplications of 22q11.21-q11.23 distal to the 22q11.21 microdeletion syndrome region.

Deletions of the 22q11.2 region distal to the 22q11.21 microdeletion syndrome region have recently been described in individuals with mental retardation and congenital anomalies.