The following information may help to address your question:
Down syndrome is usually not
Less commonly, a parent may carry a rearrangement of their chromosomes that increases their chance of having a child with Down syndrome as well as fertility problems and miscarriages. Click here to read more about this type of Down syndrome, called
A genetic professional can review your son and daughter-in-law's
Once again a genetic professional can help assess your children's, and their future offspring’s, risk for HSCR. Family history information (and where possible medical records) can be very important in assessing this risk.
These syndromes have many other signs and symptoms. When HSCR occurs as part of a syndrome, inheritance risk will depend on the parent syndrome's mode of inheritance.