Claim: Langer–Giedion syndrome occurs when an entire gene (8q23.2–q24.1) is missing and includes the EXT1 gene.
Evidence: 646 (CCDS) The syndrome occurs when a small piece of chromosome 8's long arm, which contains a number of genes, is missing. The loss of these genes is responsible for some of the overall characteristics of Langer–Giedion syndrome.