Mary and John want to have a second child. They have a 10-year-old with Down syndrome, and they have questions about the risks of having a second child with Down syndrome. Explain the risk for the d


Mary and John want to have a second child. They have a 10-year-old with Down syndrome, and they have questions about the risks of having a second child with Down syndrome.  

Explain the risk for the development of Down syndrome and the recurrence risk in a second pregnancy.