What are the genetic changes related to Ehlers-Danlos syndrome ?
Mutations in more than a dozen genes have been found to cause Ehlers-Danlos syndrome. The classical type results most often from mutations in either the COL5A1 gene or the COL5A2 gene. Mutations in the TNXB gene have been found in a very small percentage of cases of the hypermobility type (although in most cases, the cause of this type is unknown). The vascular type results from mutations in the COL3A1 gene. PLOD1 gene mutations cause the kyphoscoliosis type. Mutations in the COL1A1 gene or the COL1A2 gene result in the arthrochalasia type. The dermatosparaxis type is caused by mutations in the ADAMTS2 gene. The other, less well-characterized forms of Ehlers-Danlos syndrome result from mutations in other genes, some of which have not been identified.  Some of the genes associated with Ehlers-Danlos syndrome, including COL1A1, COL1A2, COL3A1, COL5A1, and COL5A2, provide instructions for making pieces of several different types of collagen. These pieces assemble to form mature collagen molecules that give structure and strength to connective tissues throughout the body. Other genes, including ADAMTS2, PLOD1, and TNXB, provide instructions for making proteins that process or interact with collagen. Mutations that cause the different forms of Ehlers-Danlos syndrome disrupt the production or processing of collagen, preventing these molecules from being assembled properly. These defects weaken connective tissues in the skin, bones, and other parts of the body, resulting in the characteristic features of this condition.