What are the genetic changes related to spondylocostal dysostosis ?
Mutations in at least four genes are known to cause spondylocostal dysostosis: Mutations in the DLL3 gene cause spondylocostal dysostosis type 1; mutations in the MESP2 gene cause spondylocostal dysostosis type 2; mutations in the LFNG gene cause spondylocostal dysostosis type 3; and mutations in the HES7 gene cause spondylocostal dysostosis type 4. The genetic cause of AD spondylocostal dysostosis is unknown.  The DLL3, MESP2, LFNG, and HES7 genes play a role in the Notch signaling pathway, an important pathway in embryonic development. One of the functions of the Notch pathway is separating future vertebrae from one another during early development, a process called somite segmentation. When this pathway is disrupted, somite segmentation does not occur properly, resulting in the malformation and fusion of the bones of the spine and ribs seen in spondylocostal dysostosis.  Mutations in the four identified genes account for approximately 25 percent of diagnosed spondylocostal dysostosis. Researchers suggest that additional genes in the Notch signaling pathway might also be involved.