Langer-Giedion Syndrome can be a true contiguous gene deletion syndrome a result of deletions in the the TRPS and EXT1 genes. The lack of a functional EXT1 gene causes the bone exostoses, bone anomalies and facial abnormalities which can be affecting patients. The EXT1 gene as well as the TRPS1 gene are both absent in patients and research suggests that other genes based in the 8q24.11-8q24.13 region of chromosome 8 might be deleted or non-functional also. Longer deletions in this region are seen as mental retardation as well as the other variations in symptoms stated earlier.