What are the genetic changes related to cold-induced sweating syndrome ?
About 90 percent of cases of cold-induced sweating syndrome and Crisponi syndrome result from mutations in the CRLF1 gene. These cases are designated as CISS1. The remaining 10 percent of cases are caused by mutations in the CLCF1 gene and are designated as CISS2.  The proteins produced from the CRLF1 and CLCF1 genes work together as part of a signaling pathway that is involved in the normal development of the nervous system. This pathway appears to be particularly important for the development and maintenance of motor neurons, which are nerve cells that control muscle movement. Studies suggest that this pathway also has a role in a part of the nervous system known as the sympathetic nervous system, specifically in the regulation of sweating in response to temperature changes and other factors. The proteins produced from the CRLF1 and CLCF1 genes appear to be critical for the normal development and maturation of nerve cells that control the activity of sweat glands.  Additionally, the CRLF1 and CLCF1 genes likely have functions outside the nervous system, including roles in the body's inflammatory response and in bone development. However, little is known about their involvement in these processes.  Mutations in either the CRLF1 or CLCF1 gene disrupt the normal development of several body systems, including the nervous system. The role of these genes in sympathetic nervous system development may help explain the abnormal sweating that is characteristic of this condition, including unusual sweating patterns and related problems with body temperature regulation. The involvement of these genes in motor neuron development and bone development provides clues to some of the other signs and symptoms of cold-induced sweating syndrome, including distinctive facial features, facial muscle weakness, and skeletal abnormalities. However, little is known about how CRLF1 or CLCF1 gene mutations underlie these other features of cold-induced sweating syndrome.