Original
NS is a genetic syndrome that is inherited. one parent with NS has a 50/50 chance of having children with NS. NS is caused by a mutation of one of the PTPN11 , SOS1, RAF1 or the RIT1 genes. NS can be present in every generation or skip many generations. in some cases NS has never occurred in a family. NS occurs in 1 in every 1,000 to 2,500 births.