Langer–Giedion syndrome (LGS) is a very uncommon autosomal dominant genetic disorder caused by a deletion of a small section of material on chromosome 8.

In addition, individuals with Langer–Giedion syndrome may develop hip problems similar to those seen in Legg–Calvé–Perthes disease such as progressive degeneration of the head of the thigh bone.

[citation needed] As affected individuals age they often develop benign boney growths called exostoses which project off the surfaces of the bones.

Depending on the location of the exostoses they cause numerous complications such as compression of the spinal cord, asymmetric growth of the limbs and reduced mobility.

This progresses to joint stiffness later in life when osteochondromas begin to develop, typically between infancy and mid-childhood, which decreases mobility.

[9] The majority of individuals with Langer–Giedion syndrome have sparse scalp hair; this is particularly severe in males, who often experience alopecia shortly after puberty.