Understanding the Genetics Behind Cystic Fibrosis

If two carrier parents are planning to have a second child, what does this mean about their risk? Some may think that having had one child with the disease means that the second child has a higher or lower risk of getting it too. Turns out though, that genes don't discriminate against first or second-borns. Each child's risk resets with each conception. The chance that the second or even third child will get cystic fibrosis is still 25% regardless of whether or not the first child got the disease or not.